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Chemistry guideFirst assessment 2016

Chemistry guideFirst assessment 2016

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International Baccalaureate, Baccalauréat International and Bachillerato Internacional are registered trademarks of the International Baccalaureate Organization.

Diploma ProgrammeChemistry guide

Published February 2014Updated February 2015

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IB mission statementThe International Baccalaureate aims to develop inquiring, knowledgeable and caring young people who help to create a better and more peaceful world through intercultural understanding and respect.

To this end the organization works with schools, governments and international organizations to develop challenging programmes of international education and rigorous assessment.

These programmes encourage students across the world to become active, compassionate and lifelong learners who understand that other people, with their differences, can also be right.

© International Baccalaureate Organization 2014

Chemistry guide

Contents

Introduction 1

Purpose of this document 1

The Diploma Programme 2

Nature of science 6

Nature of chemistry 13

Aims 18

Assessment objectives 19

Syllabus 20

Syllabus outline 20

Approaches to the teaching of chemistry 22

Syllabus content 27

Assessment 167

Assessment in the Diploma Programme 167

Assessment outline—SL 169

Assessment outline—HL 170

External assessment 171

Internal assessment 173

The group 4 project 185

Appendices 190

Glossary of command terms 190

Bibliography 193

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Introduction

Purpose of this document

This publication is intended to guide the planning, teaching and assessment of the subject in schools. Subject teachers are the primary audience, although it is expected that teachers will use the guide to inform students and parents about the subject.

This guide can be found on the subject page of the online curriculum centre (OCC) at http://occ.ibo.org, a password-protected IB website designed to support IB teachers. It can also be purchased from the IB store at http://store.ibo.org.

Additional resourcesAdditional publications such as teacher support materials, subject reports, internal assessment guidance and grade descriptors can also be found on the OCC. Past examination papers as well as markschemes can be purchased from the IB store.

Teachers are encouraged to check the OCC for additional resources created or used by other teachers. Teachers can provide details of useful resources, for example: websites, books, videos, journals or teaching ideas.

AcknowledgmentThe IB wishes to thank the educators and associated schools for generously contributing time and resources to the production of this guide.

First assessment 2016

Chemistry guide22

Introduction

The Diploma Programme

The Diploma Programme is a rigorous pre-university course of study designed for students in the 16 to 19 age range. It is a broad-based two-year course that aims to encourage students to be knowledgeable and inquiring, but also caring and compassionate. There is a strong emphasis on encouraging students to develop intercultural understanding, open-mindedness, and the attitudes necessary for them to respect and evaluate a range of points of view.

The Diploma Programme modelThe course is presented as six academic areas enclosing a central core (see figure 1). It encourages the concurrent study of a broad range of academic areas. Students study two modern languages (or a modern language and a classical language), a humanities or social science subject, a science, mathematics and one of the creative arts. It is this comprehensive range of subjects that makes the Diploma Programme a demanding course of study designed to prepare students effectively for university entrance. In each of the academic areas students have flexibility in making their choices, which means they can choose subjects that particularly interest them and that they may wish to study further at university.

Figure 1Diploma Programme model


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Choosing the right combinationStudents are required to choose one subject from each of the six academic areas, although they can, instead of an arts subject, choose two subjects from another area. Normally, three subjects (and not more than four) are taken at higher level (HL), and the others are taken at standard level (SL). The IB recommends 240 teaching hours for HL subjects and 150 hours for SL. Subjects at HL are studied in greater depth and breadth than at SL.

At both levels, many skills are developed, especially those of critical thinking and analysis. At the end of the course, students’ abilities are measured by means of external assessment. Many subjects contain some element of coursework assessed by teachers.

The core of the Diploma Programme modelAll Diploma Programme students participate in the three course elements that make up the core of the model. Theory of knowledge (TOK) is a course that is fundamentally about critical thinking and inquiry into the process of knowing rather than about learning a specific body of knowledge. The TOK course examines the nature of knowledge and how we know what we claim to know. It does this by encouraging students to analyse knowledge claims and explore questions about the construction of knowledge. The task of TOK is to emphasize connections between areas of shared knowledge and link them to personal knowledge in such a way that an individual becomes more aware of his or her own perspectives and how they might differ from others.

Creativity, action, service (CAS) is at the heart of the Diploma Programme. The emphasis in CAS is on helping students to develop their own identities, in accordance with the ethical principles embodied in the IB mission statement and the IB learner profile. It involves students in a range of activities alongside their academic studies throughout the Diploma Programme. The three strands of CAS are Creativity (arts and other experiences that involve creative thinking), Action (physical exertion contributing to a healthy lifestyle) and Service (an unpaid and voluntary exchange that has a learning benefit for the student). Possibly, more than any other component in the Diploma Programme, CAS contributes to the IB’s mission to create a better and more peaceful world through intercultural understanding and respect.

The extended essay, including the world studies extended essay, offers the opportunity for IB students to investigate a topic of special interest, in the form of a 4,000-word piece of independent research. The area of research undertaken is chosen from one of the students’ Diploma Programme subjects, or in the case of the interdisciplinary world studies essay, two subjects, and acquaints them with the independent research and writing skills expected at university. This leads to a major piece of formally presented, structured writing, in which ideas and findings are communicated in a reasoned and coherent manner, appropriate to the subject or subjects chosen. It is intended to promote high-level research and writing skills, intellectual discovery and creativity. As an authentic learning experience it provides students with an opportunity to engage in personal research on a topic of choice, under the guidance of a supervisor.


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Approaches to teaching and approaches to learningApproaches to teaching and learning across the Diploma Programme refer to deliberate strategies, skills and attitudes which permeate the teaching and learning environment. These approaches and tools, intrinsically linked with the learner profile attributes, enhance student learning and assist student preparation for the Diploma Programme assessment and beyond. The aims of approaches to teaching and learning in the Diploma Programme are to:

• empower teachers as teachers of learners as well as teachers of content

• empower teachers to create clearer strategies for facilitating learning experiences in which students are more meaningfully engaged in structured inquiry and greater critical and creative thinking

• promote both the aims of individual subjects (making them more than course aspirations) and linking previously isolated knowledge (concurrency of learning)

• encourage students to develop an explicit variety of skills that will equip them to continue to be actively engaged in learning after they leave school, and to help them not only obtain university admission through better grades but also prepare for success during tertiary education and beyond

• enhance further the coherence and relevance of the students’ Diploma Programme experience

• allow schools to identify the distinctive nature of an IB Diploma Programme education, with its blend of idealism and practicality.

The five approaches to learning (developing thinking skills, social skills, communication skills, self-management skills and research skills) along with the six approaches to teaching (teaching that is inquiry-based, conceptually focused, contextualized, collaborative, differentiated and informed by assessment) encompass the key values and principles that underpin IB pedagogy.

The IB mission statement and the IB learner profileThe Diploma Programme aims to develop in students the knowledge, skills and attitudes they will need to fulfill the aims of the IB, as expressed in the organization’s mission statement and the learner profile. Teaching and learning in the Diploma Programme represent the reality in daily practice of the organization’s educational philosophy.

Academic honestyAcademic honesty in the Diploma Programme is a set of values and behaviours informed by the attributes of the learner profile. In teaching, learning and assessment, academic honesty serves to promote personal integrity, engender respect for the integrity of others and their work, and ensure that all students have an equal opportunity to demonstrate the knowledge and skills they acquire during their studies.

All coursework—including work submitted for assessment—is to be authentic, based on the student’s individual and original ideas with the ideas and work of others fully acknowledged. Assessment tasks that require teachers to provide guidance to students or that require students to work collaboratively must be completed in full compliance with the detailed guidelines provided by the IB for the relevant subjects.

For further information on academic honesty in the IB and the Diploma Programme, please consult the IB publications Academic honesty (2011), The Diploma Programme: From principles into practice (2009) and General regulations: Diploma Programme (2011). Specific information regarding academic honesty as it pertains to external and internal assessment components of this Diploma Programme subject can be found in this guide.


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Acknowledging the ideas or work of another personCoordinators and teachers are reminded that candidates must acknowledge all sources used in work submitted for assessment. The following is intended as a clarification of this requirement.

Diploma Programme candidates submit work for assessment in a variety of media that may include audio-visual material, text, graphs, images and/or data published in print or electronic sources. If a candidate uses the work or ideas of another person the candidate must acknowledge the source using a standard style of referencing in a consistent manner. A candidate’s failure to acknowledge a source will be investigated by the IB as a potential breach of regulations that may result in a penalty imposed by the IB final award committee.

The IB does not prescribe which style(s) of referencing or in-text citation should be used by candidates; this is left to the discretion of appropriate faculty/staff in the candidate’s school. The wide range of subjects, three response languages and the diversity of referencing styles make it impractical and restrictive to insist on particular styles. In practice, certain styles may prove most commonly used, but schools are free to choose a style that is appropriate for the subject concerned and the language in which candidates’ work is written. Regardless of the reference style adopted by the school for a given subject, it is expected that the minimum information given includes: name of author, date of publication, title of source, and page numbers as applicable.

Candidates are expected to use a standard style and use it consistently so that credit is given to all sources used, including sources that have been paraphrased or summarized. When writing text candidates must clearly distinguish between their words and those of others by the use of quotation marks (or other method, such as indentation) followed by an appropriate citation that denotes an entry in the bibliography. If an electronic source is cited, the date of access must be indicated. Candidates are not expected to show faultless expertise in referencing, but are expected to demonstrate that all sources have been acknowledged. Candidates must be advised that audio-visual material, text, graphs, images and/or data published in print or in electronic sources that is not their own must also attribute the source. Again, an appropriate style of referencing/citation must be used.

Learning diversity and learning support requirementsSchools must ensure that equal access arrangements and reasonable adjustments are provided to candidates with learning support requirements that are in line with the IB documents Candidates with assessment access requirements and Learning diversity in the International Baccalaureate programmes: Special educational needs within the IB programmes.

Chemistry guide66

Introduction

Nature of science

The Nature of science (NOS) is an overarching theme in the biology, chemistry and physics courses. This section, titled Nature of science, is in the biology, chemistry and physics guides to support teachers in their understanding of what is meant by the nature of science. The “Nature of science” section of the guide provides a comprehensive account of the nature of science in the 21st century. It will not be possible to cover in this document all the themes in detail in the three science courses, either for teaching or assessment.

It has a paragraph structure (1.1, 1.2, etc) to link the significant points made to the syllabus (landscape pages) references on the NOS. The NOS parts in the subject-specific sections of the guide are examples of a particular understanding. The NOS statement(s) above every sub-topic outline how one or more of the NOS themes can be exemplified through the understandings, applications and skills in that sub-topic. These are not a repeat of the NOS statements found below but an elaboration of them in a specific context. See the section on “Format of the syllabus”.

Technology

Although this section is about the nature of science, the interpretation of the word technology is important, and the role of technology emerging from and contributing to science needs to be clarified. In today’s world, the words science and technology are often used interchangeably, however, historically this is not the case. Technology emerged before science, and materials were used to produce useful and decorative artefacts long before there was an understanding of why materials had different properties that could be used for different purposes. In the modern world the reverse is the case: an understanding of the underlying science is the basis for technological developments. These new technologies in their turn drive developments in science.

Despite their mutual dependence they are based on different values: science on evidence, rationality and the quest for deeper understanding; technology on the practical, the appropriate and the useful with an increasingly important emphasis on sustainability.

1. What is science and what is the scientific endeavour?1.1. The underlying assumption of science is that the universe has an independent, external reality

accessible to human senses and amenable to human reason.

1.2. Pure science aims to come to a common understanding of this external universe; applied science and engineering develop technologies that result in new processes and products. However, the boundaries between these fields are fuzzy.

1.3. Scientists use a wide variety of methodologies which, taken together, make up the process of science. There is no single “scientific method”. Scientists have used, and do use, different methods at different times to build up their knowledge and ideas but they have a common understanding about what makes them all scientifically valid.

1.4. This is an exciting and challenging adventure involving much creativity and imagination as well as exacting and detailed thinking and application. Scientists also have to be ready for unplanned, surprising, accidental discoveries. The history of science shows this is a very common occurrence.

Nature of science

Chemistry guide 7

1.5. Many scientific discoveries have involved flashes of intuition and many have come from speculation or simple curiosity about particular phenomena.

1.6. Scientists have a common terminology and a common reasoning process, which involves using deductive and inductive logic through analogies and generalizations. They share mathematics, the language of science, as a powerful tool. Indeed, some scientific explanations only exist in mathematical form.

1.7. Scientists must adopt a skeptical attitude to claims. This does not mean that they disbelieve everything, but rather that they suspend judgment until they have a good reason to believe a claim to be true or false. Such reasons are based on evidence and argument.

1.8. The importance of evidence is a fundamental common understanding. Evidence can be obtained by observation or experiment. It can be gathered by human senses, primarily sight, but much modern science is carried out using instrumentation and sensors that can gather information remotely and automatically in areas that are too small, or too far away, or otherwise beyond human sense perception. Improved instrumentation and new technology have often been the drivers for new discoveries. Observations followed by analysis and deduction led to the Big Bang theory of the origin of the universe and to the theory of evolution by natural selection. In these cases, no controlled experiments were possible. Disciplines such as geology and astronomy rely strongly on collecting data in the field, but all disciplines use observation to collect evidence to some extent. Experimentation in a controlled environment, generally in laboratories, is the other way of obtaining evidence in the form of data, and there are many conventions and understandings as to how this is to be achieved.

1.9. This evidence is used to develop theories, generalize from data to form laws and propose hypotheses. These theories and hypotheses are used to make predictions that can be tested. In this way theories can be supported or opposed and can be modified or replaced by new theories.

1.10. Models, some simple, some very complex, based on theoretical understanding, are developed to explain processes that may not be observable. Computer-based mathematical models are used to make testable predictions, which can be especially useful when experimentation is not possible. Models tested against experiments or data from observations may prove inadequate, in which case they may be modified or replaced by new models.

1.11. The outcomes of experiments, the insights provided by modelling and observations of the natural world may be used as further evidence for a claim.

1.12. The growth in computing power has made modelling much more powerful. Models, usually mathematical, are now used to derive new understandings when no experiments are possible (and sometimes when they are). This dynamic modelling of complex situations involving large amounts of data, a large number of variables and complex and lengthy calculations is only possible as a result of increased computing power. Modelling of the Earth’s climate, for example, is used to predict or make a range of projections of future climatic conditions. A range of different models have been developed in this field and results from different models have been compared to see which models are most accurate. Models can sometimes be tested by using data from the past and used to see if they can predict the present situation. If a model passes this test, we gain confidence in its accuracy.

1.13. Both the ideas and the processes of science can only occur in a human context. Science is carried out by a community of people from a wide variety of backgrounds and traditions, and this has clearly influenced the way science has proceeded at different times. It is important to understand, however, that to do science is to be involved in a community of inquiry with certain common principles, methodologies, understandings and processes.

Nature of science

Chemistry guide8

2. The understanding of science2.1. Theories, laws and hypotheses are concepts used by scientists. Though these concepts are connected,

there is no progression from one to the other. These words have a special meaning in science and it is important to distinguish these from their everyday use.

2.2. Theories are themselves integrated, comprehensive models of how the universe, or parts of it, work. A theory can incorporate facts and laws and tested hypotheses. Predictions can be made from the theories and these can be tested in experiments or by careful observations. Examples are the germ theory of disease or atomic theory.

2.3. Theories generally accommodate the assumptions and premises of other theories, creating a consistent understanding across a range of phenomena and disciplines. Occasionally, however, a new theory will radically change how essential concepts are understood or framed, impacting other theories and causing what is sometimes called a “paradigm shift” in science. One of the most famous paradigm shifts in science occurred when our idea of time changed from an absolute frame of reference to an observer-dependent frame of reference within Einstein’s theory of relativity. Darwin’s theory of evolution by natural selection also changed our understanding of life on Earth.

2.4. Laws are descriptive, normative statements derived from observations of regular patterns of behaviour. They are generally mathematical in form and can be used to calculate outcomes and to make predictions. Like theories and hypotheses, laws cannot be proven. Scientific laws may have exceptions and may be modified or rejected based on new evidence. Laws do not necessarily explain a phenomenon. For example, Newton’s law of universal gravitation tells us that the force between two masses is inversely proportional to the square of the distance between them, and allows us to calculate the force between masses at any distance apart, but it does not explain why masses attract each other. Also, note that the term law has been used in different ways in science, and whether a particular idea is called a law may be partly a result of the discipline and time period at which it was developed.

2.5. Scientists sometimes form hypotheses—explanatory statements about the world that could be true or false, and which often suggest a causal relationship or a correlation between factors. Hypotheses can be tested by both experiments and observations of the natural world and can be supported or opposed.

2.6. To be scientific, an idea (for example, a theory or hypothesis) must focus on the natural world and natural explanations and must be testable. Scientists strive to develop hypotheses and theories that are compatible with accepted principles and that simplify and unify existing ideas.

2.7. The principle of Occam’s razor is used as a guide to developing a theory. The theory should be as simple as possible while maximizing explanatory power.

2.8. The ideas of correlation and cause are very important in science. A correlation is a statistical link or association between one variable and another. A correlation can be positive or negative and a correlation coefficient can be calculated that will have a value between +1, 0 and -1. A strong correlation (positive or negative) between one factor and another suggests some sort of causal relationship between the two factors but more evidence is usually required before scientists accept the idea of a causal relationship. To establish a causal relationship, ie one factor causing another, scientists need to have a plausible scientific mechanism linking the factors. This strengthens the case that one causes the other, eg smoking and lung cancer. This mechanism can be tested in experiments.

2.9. The ideal situation is to investigate the relationship between one factor and another while controlling all other factors in an experimental setting; however, this is often impossible and scientists, especially in biology and medicine, use sampling, cohort studies and case control studies to strengthen their understanding of causation when experiments (such as double blind tests and clinical trials) are not possible. Epidemiology in the field of medicine involves the statistical analysis of data to discover possible correlations when little established scientific knowledge is available or the circumstances are too difficult to control entirely. Here, as in other fields, mathematical analysis of probability also plays a role.

Nature of science

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3. The objectivity of science3.1. Data is the lifeblood of scientists and may be qualitative or quantitative. It can be obtained purely from

observations or from specifically designed experiments, remotely using electronic sensors or by direct measurement. The best data for making accurate and precise descriptions and predictions is often quantitative and amenable to mathematical analysis. Scientists analyse data and look for patterns, trends and discrepancies, attempting to discover relationships and establish causal links. This is not always possible, so identifying and classifying observations and artefacts (eg types of galaxies or fossils) is still an important aspect of scientific work.

3.2. Taking repeated measurements and large numbers of readings can improve reliability in data collection. Data can be presented in a variety of formats such as linear and logarithmic graphs that can be analysed for, say, direct or inverse proportion or for power relationships.

3.3. Scientists need to be aware of random errors and systematic errors, and use techniques such as error bars and lines of best fit on graphs to portray the data as realistically and honestly as possible. There is a need to consider whether outlying data points should be discarded or not.

3.4. Scientists need to understand the difference between errors and uncertainties, accuracy and precision, and need to understand and use the mathematical ideas of average, mean, mode, median, etc. Statistical methods such as standard deviation and chi-squared tests are often used. It is important to be able to assess how accurate a result is. A key part of the training and skill of scientists is in being able to decide which technique is appropriate in different circumstances.

3.5. It is also very important for scientists to be aware of the cognitive biases that may impact experimental design and interpretation. The confirmation bias, for example, is a well-documented cognitive bias that urges us to find reasons to reject data that is unexpected or does not conform to our expectations or desires, and to perhaps too readily accept data that agrees with these expectations or desires. The processes and methodologies of science are largely designed to account for these biases. However, care must always be taken to avoid succumbing to them.

3.6. Although scientists cannot ever be certain that a result or finding is correct, we know that some scientific results are very close to certainty. Scientists often speak of “levels of confidence” when discussing outcomes. The discovery of the existence of a Higgs boson is such an example of a “level of confidence”. This particle may never be directly observable, but to establish its “existence” particle physicists had to pass the self-imposed definition of what can be regarded as a discovery—the 5-sigma “level of certainty”—or about a 0.00003% chance that the effect is not real based on experimental evidence.

3.7. In recent decades, the growth in computing power, sensor technology and networks has allowed scientists to collect large amounts of data. Streams of data are downloaded continuously from many sources such as remote sensing satellites and space probes and large amounts of data are generated in gene sequencing machines. Experiments in CERN’s Large Hadron Collider regularly produce 23 petabytes of data per second, which is equivalent to 13.3 years of high definition TV content per second.

3.8. Research involves analysing large amounts of this data, stored in databases, looking for patterns and unique events. This has to be done using software which is generally written by the scientists involved. The data and the software may not be published with the scientific results but would be made generally available to other researchers.

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Chemistry guide10

4. The human face of science4.1. Science is highly collaborative and the scientific community is composed of people working in science,

engineering and technology. It is common to work in teams from many disciplines so that different areas of expertise and specializations can contribute to a common goal that is beyond one scientific field. It is also the case that how a problem is framed in the paradigm of one discipline might limit possible solutions, so framing problems using a variety of perspectives, in which new solutions are possible, can be extremely useful.

4.2. Teamwork of this sort takes place with the common understanding that science should be open-minded and independent of religion, culture, politics, nationality, age and gender. Science involves the free global interchange of information and ideas. Of course, individual scientists are human and may have biases and prejudices, but the institutions, practices and methodologies of science help keep the scientific endeavour as a whole unbiased.

4.3. As well as collaborating on the exchange of results, scientists work on a daily basis in collaborative groups on a small and large scale within and between disciplines, laboratories, organizations and countries, facilitated even more by virtual communication. Examples of large-scale collaboration include:

– The Manhattan project, the aim of which was to build and test an atomic bomb. It eventually employed more than 130,000 people and resulted in the creation of multiple production and research sites that operated in secret, culminating in the dropping of two atomic bombs on Hiroshima and Nagasaki.

– The Human Genome Project (HGP), which was an international scientific research project set up to map the human genome. The $3-billion project beginning in 1990 produced a draft of the genome in 2000. The sequence of the DNA is stored in databases available to anyone on the internet.

– The IPCC (Intergovernmental Panel on Climate Change), organized under the auspices of The United Nations, is officially composed of about 2,500 scientists. They produce reports summarizing the work of many more scientists from all around the world.

– CERN, the European Organization for Nuclear Research, an international organization set up in 1954, is the world’s largest particle physics laboratory. The laboratory, situated in Geneva, employs about 2,400 people and shares results with 10,000 scientists and engineers covering over 100 nationalities from 600 or more universities and research facilities.

All the above examples are controversial to some degree and have aroused emotions amongst scientists and the public.

4.4. Scientists spend a considerable amount of time reading the published results of other scientists. They publish their own results in scientific journals after a process called peer review. This is when the work of a scientist or, more usually, a team of scientists is anonymously and independently reviewed by several scientists working in the same field who decide if the research methodologies are sound and if the work represents a new contribution to knowledge in that field. They also attend conferences to make presentations and display posters of their work. Publication of peer-reviewed journals on the internet has increased the efficiency with which the scientific literature can be searched and accessed. There are a large number of national and international organizations for scientists working in specialized areas within subjects.

4.5. Scientists often work in areas, or produce findings, that have significant ethical and political implications. These areas include cloning, genetic engineering of food and organisms, stem cell and reproductive technologies, nuclear power, weapons development (nuclear, chemical and biological), transplantation of tissue and organs and in areas that involve testing on animals (see IB animal experimentation policy). There are also questions involving intellectual property rights and

Nature of science

Chemistry guide 11

the free exchange of information that may impact significantly on a society. Science is undertaken in universities, commercial companies, government organizations, defence agencies and international organizations. Questions of patents and intellectual property rights arise when work is done in a protected environment.

4.6. The integrity and honest representation of data is paramount in science—results should not be fixed or manipulated or doctored. To help ensure academic honesty and guard against plagiarism, all sources are quoted and appropriate acknowledgment made of help or support. Peer review and the scrutiny and skepticism of the scientific community also help achieve these goals.

4.7. All science has to be funded and the source of the funding is crucial in decisions regarding the type of research to be conducted. Funding from governments and charitable foundations is sometimes for pure research with no obvious direct benefit to anyone whereas funding from private companies is often for applied research to produce a particular product or technology. Political and economic factors often determine the nature and extent of the funding. Scientists often have to spend time applying for research grants and have to make a case for what they want to research.

4.8. Science has been used to solve many problems and improve man’s lot, but it has also been used in morally questionable ways and in ways that inadvertently caused problems. Advances in sanitation, clean water supplies and hygiene led to significant decreases in death rates but without compensating decreases in birth rates this led to huge population increases with all the problems of resources, energy and food supplies that entails. Ethical discussions, risk-benefit analyses, risk assessment and the precautionary principle are all parts of the scientific way of addressing the common good.

5. Scientific literacy and the public understanding of science5.1. An understanding of the nature of science is vital when society needs to make decisions involving

scientific findings and issues. How does the public judge? It may not be possible to make judgments based on the public’s direct understanding of a science, but important questions can be asked about whether scientific processes were followed and scientists have a role in answering such questions.

5.2. As experts in their particular fields, scientists are well placed to explain to the public their issues and findings. Outside their specializations, they may be no more qualified than ordinary citizens to advise others on scientific issues, although their understanding of the processes of science can help them to make personal decisions and to educate the public as to whether claims are scientifically credible.

5.3. As well as comprising knowledge of how scientists work and think scientific literacy involves being aware of faulty reasoning. There are many cognitive biases/fallacies of reasoning to which people are susceptible (including scientists) and these need to be corrected whenever possible. Examples of these are the confirmation bias, hasty generalizations, post hoc ergo propter hoc (false cause), the straw man fallacy, redefinition (moving the goal posts), the appeal to tradition, false authority and the accumulation of anecdotes being regarded as evidence.

5.4. When such biases and fallacies are not properly managed or corrected, or when the processes and checks and balances of science are ignored or misapplied, the result is pseudoscience. Pseudoscience is the term applied to those beliefs and practices which claim to be scientific but do not meet or follow the standards of proper scientific methodologies, ie they lack supporting evidence or a theoretical framework, are not always testable and hence falsifiable, are expressed in a non-rigorous or unclear manner and often fail to be supported by scientific testing.

5.5. Another key issue is the use of appropriate terminology. Words that scientists agree on as being scientific terms will often have a different meaning in everyday life and scientific discourse with the public needs to take this into account. For example, a theory in everyday use means a hunch or

Nature of science

Chemistry guide12

speculation, but in science an accepted theory is a scientific idea that has produced predictions that have been thoroughly tested in many different ways. An aerosol is just a spray can to the general public, but in science it is a suspension of solid or liquid particles in a gas.

5.6. Whatever the field of science—whether it is in pure research, applied research or in engineering new technology—there is boundless scope for creative and imaginative thinking. Science has achieved a great deal but there are many, many unanswered questions to challenge future scientists.

The flow chart below is part of an interactive flow chart showing the scientific process of inquiry in practice. The interactive version can be found at “How science works: The flowchart”. Understanding Science. University of California Museum of Paleontology. 1 February 2013 <http://undsci.berkeley.edu/article/scienceflowchart>.

Supportive, contradictory, surprisingor inconclusive data may...

Developtechnology

Addresssocietal issues

Satisfycuriosity

Solve everydayproblems

Buildknowledge

Informpolicy

Makingobservations

Askingquestions

Findinginspiration

Exploring theliterature

Sharing dataand ideas

...oppose ahypothesis.

Discussion withcolleagues

Feedback andpeer review

Coming upwith new

questions/ideas

Publication

Replication

Theorybuilding

EXPLORATIONAND DISCOVERY

COMMUNITYANALYSIS AND

FEEDBACK

BENEFITS ANDOUTCOMES

TESTINGIDEAS

Gathering data

Interpreting data

New technology

Curiosity

Practical problem

Personal motivation

Surprising observation

Serendipity

Hypotheses Expectedresults/observations

Actualresults/observations

...support ahypothesis.

... inspirerevised/newhypothesis.

... inspirerevised

assumptions.

How science works

www.understandingscience.org© 2008 The University of California Museum of Paleontology, Berkeley, and the Regents of the University of California

Figure 2Pathways to scientific discovery

Chemistry guide 1313

Introduction

Nature of chemistry

Chemistry is an experimental science that combines academic study with the acquisition of practical and investigational skills. It is often called the central science, as chemical principles underpin both the physical environment in which we live and all biological systems. Apart from being a subject worthy of study in its own right, chemistry is a prerequisite for many other courses in higher education, such as medicine, biological science and environmental science, and serves as useful preparation for employment.

Earth, water, air and fire are often said to be the four classical elements. They have connections with Hinduism and Buddhism. The Greek philosopher Plato was the first to call these entities elements. The study of chemistry has changed dramatically from its origins in the early days of alchemists, who had as their quest the transmutation of common metals into gold. Although today alchemists are not regarded as being true scientists, modern chemistry has the study of alchemy as its roots. Alchemists were among the first to develop strict experimentation processes and laboratory techniques. Robert Boyle, often credited with being the father of modern chemistry, began experimenting as an alchemist.

Despite the exciting and extraordinary development of ideas throughout the history of chemistry, certain things have remained unchanged. Observations remain essential at the very core of chemistry, and this sometimes requires decisions about what to look for. The scientific processes carried out by the most eminent scientists in the past are the same ones followed by working chemists today and, crucially, are also accessible to students in schools. The body of scientific knowledge has grown in size and complexity, and the tools and skills of theoretical and experimental chemistry have become so specialized, that it is difficult (if not impossible) to be highly proficient in both areas. While students should be aware of this, they should also know that the free and rapid interplay of theoretical ideas and experimental results in the public scientific literature maintains the crucial link between these fields.

The Diploma Programme chemistry course includes the essential principles of the subject but also, through selection of an option, allows teachers some flexibility to tailor the course to meet the needs of their students. The course is available at both standard level (SL) and higher level (HL), and therefore accommodates students who wish to study chemistry as their major subject in higher education and those who do not.

At the school level both theory and experiments should be undertaken by all students. They should complement one another naturally, as they do in the wider scientific community. The Diploma Programme chemistry course allows students to develop traditional practical skills and techniques and to increase facility in the use of mathematics, which is the language of science. It also allows students to develop interpersonal skills, and digital technology skills, which are essential in 21st century scientific endeavour and are important life-enhancing, transferable skills in their own right.

Teaching approachThere are a variety of approaches to the teaching of chemistry. By its very nature, chemistry lends itself to an experimental approach, and it is expected that this will be reflected throughout the course.

The order in which the syllabus is arranged is not the order in which it should be taught, and it is up to individual teachers to decide on an arrangement that suits their circumstances. Sections of the option material may be taught within the core or the additional higher level (AHL) material if desired, or the option material can be taught as a separate unit.

Nature of chemistry

Chemistry guide14

Science and the international dimensionScience itself is an international endeavour—the exchange of information and ideas across national boundaries has been essential to the progress of science. This exchange is not a new phenomenon but it has accelerated in recent times with the development of information and communication technologies. Indeed, the idea that science is a Western invention is a myth—many of the foundations of modern-day science were laid many centuries before by Arabic, Indian and Chinese civilizations, among others. Teachers are encouraged to emphasize this contribution in their teaching of various topics, perhaps through the use of timeline websites. The scientific method in its widest sense, with its emphasis on peer review, open-mindedness and freedom of thought, transcends politics, religion, gender and nationality. Where appropriate within certain topics, the syllabus details sections in the group 4 guides contain links illustrating the international aspects of science.

On an organizational level, many international bodies now exist to promote science. United Nations bodies such as UNESCO, UNEP and WMO, where science plays a prominent part, are well known, but in addition there are hundreds of international bodies representing every branch of science. The facilities for large-scale research in, for example, particle physics and the Human Genome Project are expensive, and only joint ventures involving funding from many countries allow this to take place. The data from such research is shared by scientists worldwide. Group 4 teachers and students are encouraged to access the extensive websites and databases of these international scientific organizations to enhance their appreciation of the international dimension.

Increasingly there is a recognition that many scientific problems are international in nature and this has led to a global approach to research in many areas. The reports of the Intergovernmental Panel on Climate Change are a prime example of this. On a practical level, the group 4 project (which all science students must undertake) mirrors the work of real scientists by encouraging collaboration between schools across the regions.

The power of scientific knowledge to transform societies is unparalleled. It has the potential to produce great universal benefits, or to reinforce inequalities and cause harm to people and the environment. In line with the IB mission statement, group 4 students need to be aware of the moral responsibility of scientists to ensure that scientific knowledge and data are available to all countries on an equitable basis and that they have the scientific capacity to use this for developing sustainable societies.

Students’ attention should be drawn to sections of the syllabus with links to international-mindedness. Examples of issues relating to international-mindedness are given within sub-topics in the syllabus content. Teachers could also use resources found on the Global Engage website (http://globalengage.ibo.org).

Distinction between SL and HLGroup 4 students at standard level (SL) and higher level (HL) undertake a common core syllabus, a common internal assessment (IA) scheme and have some overlapping elements in the option studied. They are presented with a syllabus that encourages the development of certain skills, attributes and attitudes, as described in the “Assessment objectives” section of this guide.

While the skills and activities of group 4 science subjects are common to students at both SL and HL, students at HL are required to study some topics in greater depth, in the additional higher level (AHL) material and in the common options. The distinction between SL and HL is one of breadth and depth.

Nature of chemistry

Chemistry guide 15

Prior learningPast experience shows that students will be able to study a group 4 science subject at SL successfully with no background in, or previous knowledge of, science. Their approach to learning, characterized by the IB learner profile attributes, will be significant here.

However, for most students considering the study of a group 4 subject at HL, while there is no intention to restrict access to group 4 subjects, some previous exposure to formal science education would be necessary. Specific topic details are not specified but students who have undertaken the IB Middle Years Programme (MYP) or studied an equivalent national science qualification or a school-based science course would be well prepared for an HL subject.

Links to the Middle Years ProgrammeStudents who have undertaken the MYP science, design and mathematics courses will be well prepared for group 4 subjects. The alignment between MYP science and Diploma Programme group 4 courses allows for a smooth transition for students between programmes. The concurrent planning of the new group 4 courses and MYP: Next chapter (both launched in 2014) has helped develop a closer alignment.

Scientific inquiry is central to teaching and learning science in the MYP. It enables students to develop a way of thinking and a set of skills and processes that, while allowing them to acquire and use knowledge, equip them with the capabilities to tackle, with confidence, the internal assessment component of group 4 subjects. The vision of MYP sciences is to contribute to the development of students as 21st century learners. A holistic sciences programme allows students to develop and utilize a mixture of cognitive abilities, social skills, personal motivation, conceptual knowledge and problem-solving competencies within an inquiry-based learning environment (Rhoton 2010). Inquiry aims to support students’ understanding by providing them with opportunities to independently and collaboratively investigate relevant issues through both research and experimentation. This forms a firm base of scientific understanding with deep conceptual roots for students entering group 4 courses.

In the MYP, teachers make decisions about student achievement using their professional judgment, guided by criteria that are public, precise and known in advance, ensuring that assessment is transparent. The IB describes this approach as “criterion-related”—a philosophy of assessment that is neither “norm-referenced” (where students must be compared to each other and to an expected distribution of achievement) nor “criterion-referenced” (where students must master all strands of specific criteria at lower achievement levels before they can be considered to have achieved the next level). It is important to emphasize that the single most important aim of MYP assessment (consistent with the PYP and DP) is to support curricular goals and encourage appropriate student learning. Assessments are based upon evaluating course aims and objectives and, therefore, effective teaching to the course requirements also ensures effective teaching for formal assessment requirements. Students need to understand what the assessment expectations, standards and practices are and these should all be introduced early and naturally in teaching, as well as in class and homework activities. Experience with criterion-related assessment greatly assists students entering group 4 courses with understanding internal assessment requirements.

MYP science is a concept-driven curriculum, aimed at helping the learner construct meaning through improved critical thinking and the transfer of knowledge. At the top level are key concepts which are broad, organizing, powerful ideas that have relevance within the science course but also transcend it, having relevance in other subject groups. These key concepts facilitate both disciplinary and interdisciplinary learning as well as making connections with other subjects. While the key concepts provide breadth, the related concepts in MYP science add depth to the programme. The related concept can be considered to be the big idea of the unit which brings focus and depth and leads students towards the conceptual understanding.

Nature of chemistry

Chemistry guide16

Across the MYP, there are 16 key concepts, with the three highlighted below as the focus for MYP science.

The key concepts across the MYP curriculum

Aesthetics Change Communication Communities

Connections Creativity Culture Development

Form Global interactions Identity Logic

Perspective Relationships SystemsTime, place and space

MYP students may in addition undertake an optional onscreen concept-based assessment as further preparation for Diploma Programme science courses.

Science and theory of knowledgeThe theory of knowledge (TOK) course (first assessment 2015) engages students in reflection on the nature of knowledge and on how we know what we claim to know. The course identifies eight ways of knowing: reason, emotion, language, sense perception, intuition, imagination, faith and memory. Students explore these means of producing knowledge within the context of various areas of knowledge: the natural sciences, the social sciences, the arts, ethics, history, mathematics, religious knowledge systems and indigenous knowledge systems. The course also requires students to make comparisons between the different areas of knowledge, reflecting on how knowledge is arrived at in the various disciplines, what the disciplines have in common, and the differences between them.

TOK lessons can support students in their study of science, just as the study of science can support students in their TOK course. TOK provides a space for students to engage in stimulating wider discussions about questions such as what it means for a discipline to be a science, or whether there should be ethical constraints on the pursuit of scientific knowledge. It also provides an opportunity for students to reflect on the methodologies of science, and how these compare to the methodologies of other areas of knowledge. It is now widely accepted that there is no one scientific method, in the strict Popperian sense. Instead, the sciences utilize a variety of approaches in order to produce explanations for the behaviour of the natural world. The different scientific disciplines share a common focus on utilizing inductive and deductive reasoning, on the importance of evidence, and so on. Students are encouraged to compare and contrast these methods with the methods found in, for example, the arts or in history.

In this way there are rich opportunities for students to make links between their science and TOK courses. One way in which science teachers can help students to make these links to TOK is by drawing students’ attention to knowledge questions which arise from their subject content. Knowledge questions are open-ended questions about knowledge, and include questions such as:

• How do we distinguish science from pseudoscience?

• When performing experiments, what is the relationship between a scientist’s expectation and their perception?

• How does scientific knowledge progress?

• What is the role of imagination and intuition in the sciences?

• What are the similarities and differences in methods in the natural sciences and the human sciences?

Nature of chemistry

Chemistry guide 17

Examples of relevant knowledge questions are provided throughout this guide within the sub-topics in the syllabus content. Teachers can also find suggestions of interesting knowledge questions for discussion in the “Areas of knowledge” and “Knowledge frameworks” sections of the TOK guide. Students should be encouraged to raise and discuss such knowledge questions in both their science and TOK classes.

Chemistry guide1818

Introduction

Aims

Group 4 aimsThrough studying biology, chemistry or physics, students should become aware of how scientists work and communicate with each other. While the scientific method may take on a wide variety of forms, it is the emphasis on a practical approach through experimental work that characterizes these subjects.

The aims enable students, through the overarching theme of the Nature of science, to:

1. appreciate scientific study and creativity within a global context through stimulating and challenging opportunities

2. acquire a body of knowledge, methods and techniques that characterize science and technology

3. apply and use a body of knowledge, methods and techniques that characterize science and technology

4. develop an ability to analyse, evaluate and synthesize scientific information

5. develop a critical awareness of the need for, and the value of, effective collaboration and communication during scientific activities

6. develop experimental and investigative scientific skills including the use of current technologies

7. develop and apply 21st century communication skills in the study of science

8. become critically aware, as global citizens, of the ethical implications of using science and technology

9. develop an appreciation of the possibilities and limitations of science and technology

10. develop an understanding of the relationships between scientific disciplines and their influence on other areas of knowledge.


Introduction

Assessment objectives

The assessment objectives for biology, chemistry and physics reflect those parts of the aims that will be formally assessed either internally or externally. These assessments will centre upon the nature of science. It is the intention of these courses that students are able to fulfill the following assessment objectives:

1. Demonstrate knowledge and understanding of:

a. facts, concepts, and terminology

b. methodologies and techniques

c. communicating scientific information.

2. Apply:

a. facts, concepts, and terminology


c. methods of communicating scientific information.

3. Formulate, analyse and evaluate:

a. hypotheses, research questions and predictions


c. primary and secondary data

d. scientific explanations.

4. Demonstrate the appropriate research, experimental, and personal skills necessary to carry out insightful and ethical investigations.

Chemistry guide2020

Syllabus

Syllabus outline

Syllabus component Recommended teaching hours

SL HL

Core1. Stoichiometric relationships

2. Atomic structure

3. Periodicity

4. Chemical bonding and structure

5. Energetics/thermochemistry

6. Chemical kinetics

7. Equilibrium

8. Acids and bases

9. Redox processes

10. Organic chemistry

11. Measurement and data processing

9513.5

6

6

13.5

9

7

4.5

6.5

8

11

10

Additional higher level (AHL)12. Atomic structure

13. The periodic table—the transition metals

14. Chemical bonding and structure

15. Energetics/thermochemistry

16. Chemical kinetics

17. Equilibrium

18. Acids and bases

19. Redox processes

20. Organic chemistry

21. Measurement and analysis

602

4

7

7

6

4

10

6

12

2

OptionA. Materials

B. Biochemistry

C. Energy

D. Medicinal chemistry

1515

15

15

15

2525

25

25

25

Syllabus outline

Chemistry guide 21

Syllabus component Recommended teaching hours

SL HL

Practical scheme of workPractical activities

Individual investigation (internal assessment—IA)

Group 4 project

4020

10

10

6040

10

10

Total teaching hours 150 240

The recommended teaching time is 240 hours to complete HL courses and 150 hours to complete SL courses as stated in the document General regulations: Diploma Programme (2011) (page 4, Article 8.2).

Chemistry guide2222

Syllabus

Approaches to the teaching of chemistry

Format of the syllabusThe format of the syllabus section of the group 4 guides is the same for each subject physics, chemistry and biology. This new structure gives prominence and focus to the teaching and learning aspects.

Topics or optionsTopics are numbered and options are indicated by a letter. For example, “Topic 6: Chemical kinetics”, or “Option D: Medicinal chemistry”.

Sub-topicsSub-topics are numbered as follows, “6.1 Collision theory and rates of reaction”. Further information and guidance about possible teaching times are contained in the teacher support materials.

Each sub-topic begins with an essential idea. The essential idea is an enduring interpretation that is considered part of the public understanding of science. This is followed by a section on the “Nature of science”. This gives specific examples in context illustrating some aspects of the nature of science. These are linked directly to specific references in the “Nature of Science” section of the guide to support teachers in their understanding of the general theme to be addressed.

Under the overarching Nature of Science theme there are two columns. The f irst column lists “Understandings”, which are the main general ideas to be taught. There follows an “Applications and skills” section that outlines the specific applications and skills to be developed from the understandings. A “Guidance” section gives information about the limits and constraints and the depth of treatment required for teachers and examiners. The contents of the “Nature of Science” section above the two columns and contents of the first column are all legitimate items for assessment. In addition, some assessment of international-mindedness in science, from the content of the second column, will take place as in the previous course.

The second column gives suggestions to teachers about relevant references to international-mindedness. It also gives examples of TOK knowledge questions (see Theory of knowledge guide published 2013) that can be used to focus students’ thoughts on the preparation of the TOK prescribed essay. The “Links” section may link the sub-topic to other parts of the subject syllabus, to other Diploma Programme subject guides or to real-world applications. Finally, the “Aims” section refers to how specific group 4 aims are being addressed in the sub-topic.


Chemistry guide 23

Format of the guideTopic 1: <Title>

Essential idea: This lists the essential idea for each sub-topic.

1.1 Sub-topic

Nature of Science: Relates the sub-topic to the overarching theme of Nature of Science.

Understandings:

• This section will provide specifics of the content requirements for each sub-topic.

Applications and skills:

• The content of this section gives details of how students are to apply the understandings. For example, these applications could involve demonstrating mathematical calculations or practical skills.

Guidance:

• This section will provide specifics and give constraints to the requirements for the understandings and applications and skills.

• This section will also include links to specific sections in the data booklet.

International-mindedness:

• Ideas that teachers can easily integrate into the delivery of their lessons.

Theory of knowledge:

• Examples of TOK knowledge questions.

Utilization: (including syllabus and cross-curricular links)

• Links to other topics within the Chemistry guide, to a variety of real-world applications and to other Diploma Programme courses.

Aims:

• Links to the group 4 subject aims.

Group 4 experimental skillsI hear and I forget. I see and I remember. I do and I understand.

(Confucius)

Integral to the experience of students in any of the group 4 courses is their experience in the classroom, laboratory, or in the field. Practical activities allow students to interact directly with natural phenomena and secondary data sources. These experiences provide the students with the opportunity to design investigations, collect data, develop manipulative skills, analyse results, collaborate with peers and evaluate and communicate their findings. Experiments can be used to introduce a topic, investigate a phenomenon or allow students to consider and examine questions and curiosities.

By providing students with the opportunity for hands-on experimentation, they are carrying out some of the same processes that scientists undertake. Experimentation allows students to experience the nature of scientific thought and investigation. All scientific theories and laws begin with observations.

It is important that students are involved in an inquiry-based practical programme that allows for the development of scientific inquiry. It is not enough for students just to be able to follow directions and to simply replicate a given experimental procedure; they must be provided with the opportunities for genuine inquiry. Developing scientific inquiry skills will give students the ability to construct an explanation based on reliable evidence and logical reasoning. Once developed, these higher order thinking skills will enable students to be lifelong learners and scientifically literate.


Chemistry guide24

A school’s practical scheme of work should allow students to experience the full breadth and depth of the course including the option. This practical scheme of work must also prepare students to undertake the individual investigation that is required for the internal assessment. The development of students’ manipulative skills should involve them being able to follow instructions accurately and demonstrate the safe, competent and methodical use of a range of techniques and equipment.

The “Applications and skills” section of the syllabus lists specific lab skills, techniques and experiments that students must experience at some point during their study of their group 4 course. Other recommended lab skills, techniques and experiments are listed in the “Aims” section of the subject-specific syllabus pages. Aim 6 of the group 4 subjects directly relates to the development of experimental and investigative skills.

Mathematical requirementsAll Diploma Programme chemistry students should be able to:

• perform the basic arithmetic functions: addition, subtraction, multiplication and division

• carry out calculations involving means, decimals, fractions, percentages, ratios, approximations and reciprocals

• use standard notation (for example, 3.6 × 106)

• use direct and inverse proportion

• solve simple algebraic equations

• plot graphs (with suitable scales and axes) including two variables that show linear and non-linear relationships

• interpret graphs, including the significance of gradients, changes in gradients, intercepts and areas

• interpret data presented in various forms (for example, bar charts, histograms and pie charts).

Data bookletThe data booklet must be viewed as an integral part of the chemistry programme. It should be used throughout the delivery of the course and not just reserved for use during the external assessments. The data booklet contains useful equations, constants, data, structural formulas and tables of information. In the “Syllabus content” section of the subject guide, explicit links provide direct references to information in the data booklet which will allow students to become familiar with its use and contents. It is suggested that the data booklet be used for all in-class study and school-based assessments.

For both SL and HL external assessments, the data booklet cannot be used for paper 1, but candidates are provided with a copy of the periodic table given in section 6 of that booklet. Clean copies of the data booklet must be made available to both SL and HL candidates for papers 2 and 3.

Use of information communication technology The use of information communication technology (ICT) is encouraged throughout all aspects of the course in relation to both the practical programme and day-to-day classroom activities. Teachers should make use of the ICT pages of the teacher support materials.


Chemistry guide 25

Planning your courseThe syllabus as provided in the subject guide is not intended to be a teaching order. Instead it provides detail of what must be covered by the end of the course. A school should develop a scheme of work that best works for its students. For example, the scheme of work could be developed to match available resources, to take into account student prior learning and experience, or in conjunction with other local requirements.

HL teachers may choose to teach the core and AHL topics at the same time or teach them in a spiral fashion, by teaching the core topics in year one of the course and revisiting the core topics through the delivery of the AHL topics in year two of the course. The option topic could be taught as a stand-alone topic or could be integrated into the teaching of the core and/or AHL topics.

However the course is planned, adequate time must be provided for examination revision. Time must also be given for students to reflect on their learning experience and their growth as learners.

The IB learner profileThe chemistry course contributes to the development of attributes of the IB learner profile. By following the course, students will have engaged with the attributes of the IB learner profile. For example, the requirements of the internal assessment provide opportunities for students to develop every aspect of the profile. For each attribute of the learner profile, a number of references from the Group 4 courses are given below.

Learner profile attribute

Biology, chemistry and physics

Inquirers Aims 2 and 6

Practical work and internal assessment

Knowledgeable Aims 1 and 10, international-mindedness links


Thinkers Aims 3 and 4, Theory of knowledge links


Communicators Aims 5 and 7, external assessment


Principled Aims 8 and 9

Practical work and internal assessment. Ethical behaviour/practice (Ethical practice poster, IB animal experimentation policy), academic honesty

Open-minded Aims 8 and 9, International-mindedness links

Practical work and internal assessment, the group 4 project

Caring Aims 8 and 9

Practical work and internal assessment, the group 4 project, ethical behaviour/practice (Ethical practice poster, IB animal experimentation policy)


Chemistry guide26

Learner profile attribute

Biology, chemistry and physics

Risk-takers Aims 1 and 6


Balanced Aims 8 and 10

Practical work and internal assessment, the group 4 project and fieldwork

Reflective Aims 5 and 9



Syllabus

Syllabus content

Recommended teaching hours

Core 95 hours

Topic 1: Stoichiometric relationships 13.5

1.1 Introduction to the particulate nature of matter and chemical change

1.2 The mole concept

1.3 Reacting masses and volumes

Topic 2: Atomic structure 6

2.1 The nuclear atom

2.2 Electron configuration

Topic 3: Periodicity 6

3.1 Periodic table

3.2 Periodic trends

Topic 4: Chemical bonding and structure 13.5

4.1 Ionic bonding and structure

4.2 Covalent bonding

4.3 Covalent structures

4.4 Intermolecular forces

4.5 Metallic bonding

Topic 5: Energetics/thermochemistry 9

5.1 Measuring energy changes

5.2 Hess’s Law

5.3 Bond enthalpies

Topic 6: Chemical kinetics 7

6.1 Collision theory and rates of reaction

Topic 7: Equilibrium 4.5

7.1 Equilibrium

Syllabus content

Chemistry guide28


Topic 8: Acids and bases 6.5

8.1 Theories of acids and bases

8.2 Properties of acids and bases

8.3 The pH scale

8.4 Strong and weak acids and bases

8.5 Acid deposition

Topic 9: Redox processes 8

9.1 Oxidation and reduction

9.2 Electrochemical cells

Topic 10: Organic chemistry 11

10.1 Fundamentals of organic chemistry

10.2 Functional group chemistry

Topic 11: Measurement and data processing 10

11.1 Uncertainties and errors in measurement and results

11.2 Graphical techniques

11.3 Spectroscopic identification of organic compounds

Additional higher level (AHL) 60 hours

Topic 12: Atomic structure 2

12.1 Electrons in atoms

Topic 13: The periodic table—the transition metals 4

13.1 First-row d-block elements

13.2 Coloured complexes

Topic 14: Chemical bonding and structure 7

14.1 Covalent bonding and electron domain and molecular geometries

14.2 Hybridization

Topic 15: Energetics/thermochemistry 7

15.1 Energy cycles

15.2 Entropy and spontaneity

Syllabus content

Chemistry guide 29


Topic 16: Chemical kinetics 6

16.1 Rate expression and reaction mechanism

16.2 Activation energy

Topic 17: Equilibrium 4

17.1 The equilibrium law

Topic 18: Acids and bases 10

18.1 Lewis acids and bases

18.2 Calculations involving acids and bases

18.3 pH curves

Topic 19: Redox processes 6

19.1 Electrochemical cells

Topic 20: Organic chemistry 12

20.1 Types of organic reactions

20.2 Synthetic routes

20.3 Stereoisomerism

Topic 21: Measurement and analysis 2

21.1 Spectroscopic identification of organic compounds

Options 15 hours (SL)/25 hours (HL)A: Materials Core topicsA.1 Materials science introduction

A.2 Metals and inductively coupled plasma (ICP) spectroscopy

A.3 Catalysts

A.4 Liquid crystals

A.5 Polymers

A.6 Nanotechnology

A.7 Environmental impact—plastics

Syllabus content

Chemistry guide30

Additional higher level topicsA.8 Superconducting metals and X-ray crystallography (HL only)

A.9 Condensation polymers (HL only)

A.10 Environmental impact—heavy metals (HL only)

B: BiochemistryCore topicsB.1 Introduction to biochemistry

B.2 Proteins and enzymes

B.3 Lipids

B.4 Carbohydrates

B.5 Vitamins

B.6 Biochemistry and the environment

Additional higher level topicsB.7 Proteins and enzymes (HL only)

B.8 Nucleic acids (HL only)

B.9 Biological pigments (HL only)

B.10 Stereochemistry in biomolecules (HL only)

C: EnergyCore topicsC.1 Energy sources

C.2 Fossil fuels

C.3 Nuclear fusion and fission

C.4 Solar energy

C.5 Environmental impact—global warming

Additional higher level topicsC.6 Electrochemistry, rechargeable batteries and fuel cells (HL only)

C.7 Nuclear fusion and nuclear fission (HL only)

C.8 Photovoltaic and dye-sensitized solar cells (HL only)

D: Medicinal chemistryCore topicsD.1 Pharmaceutical products and drug action

D.2 Aspirin and penicillin

D.3 Opiates

D.4 pH regulation of the stomach

Syllabus content

Chemistry guide 31

D.5 Anti-viral medications

D.6 Environmental impact of some medications

Additional higher level topicsD.7 Taxol—a chiral auxiliary case study (HL only)

D.8 Nuclear medicine (HL only)

D.9 Drug detection and analysis (HL only)

Topic 1: Stoichiometric relationships

Chemistry guide32

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posi

tion—

shou

ld b

e co

vere

d.

Inte

rnat

iona

l-min

dedn

ess:

• C

hem

ical

sym

bols

and

equ

atio

ns a

re in

tern

atio

nal,

enab

ling

effe

ctiv

e co

mm

unic

atio

n am

ongs

t sci

entis

ts w

ithou

t nee

d fo

r tra

nsla

tion.

• IU

PA

C (I

nter

natio

nal U

nion

of P

ure

and

App

lied

Che

mis

try) i

s th

e w

orld

au

thor

ity in

dev

elop

ing

stan

dard

ized

nom

encl

atur

e fo

r bot

h or

gani

c an

d in

orga

nic

com

poun

ds.

Theo

ry o

f kno

wle

dge:

• C

hem

ical

equ

atio

ns a

re th

e “la

ngua

ge” o

f che

mis

try. H

ow d

oes

the

use

of

univ

ersa

l lan

guag

es h

elp

and

hind

er th

e pu

rsui

t of k

now

ledg

e?

• Th

e di

scov

ery

of o

xyge

n, w

hich

ove

rturn

ed th

e ph

logi

ston

theo

ry o

f co

mbu

stio

n, is

an

exam

ple

of a

par

adig

m s

hift.

How

doe

s sc

ient

ific

know

ledg

e pr

ogre

ss?

Util

izat

ion:

• R

efrig

erat

ion

and

how

it is

rela

ted

to th

e ch

ange

s of

sta

te.

• A

tom

eco

nom

y.

• Fr

eeze

-dry

ing

of fo

ods.

Core Topi

c 1:

Sto

ichi

omet

ric re

latio

nshi

ps

13.5

hou

rs


Chemistry guide 33

1.1

Intr

oduc

tion

to th

e pa

rtic

ulat

e na

ture

of m

atte

r and

che

mic

al c

hang

e

• Th

e te

rm “l

aten

t hea

t” is

not

requ

ired.

• N

ames

and

sym

bols

of e

lem

ents

are

in th

e da

ta b

ookl

et in

sec

tion

5.

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 4.

1—de

duct

ion

of fo

rmul

ae o

f ion

ic c

ompo

unds

To

pic

5.1—

enth

alpy

cyc

le re

actio

n; s

tand

ard

stat

e of

an

elem

ent o

r com

poun

d

Topi

c 6.

1—ki

netic

theo

ry

Topi

c 8.

2—ne

utra

lizat

ion

reac

tions

To

pic

10.2

—co

mbu

stio

n re

actio

ns

Opt

ion

A.4

—liq

uid

crys

tals

Aim

s:

• A

im 8

: The

neg

ativ

e en

viro

nmen

tal i

mpa

cts

of re

frige

ratio

n an

d ai

r co

nditi

onin

g sy

stem

s ar

e si

gnifi

cant

. The

use

of C

FCs

as re

frige

rant

s ha

s be

en a

maj

or c

ontri

buto

r to

ozon

e de

plet

ion.


Chemistry guide34

Esse

ntia

l ide

a: T

he m

ole

mak

es it

pos

sibl

e to

cor

rela

te th

e nu

mbe

r of p

artic

les

with

the

mas

s th

at c

an b

e m

easu

red.

1.2

The

mol

e co

ncep

t

Nat

ure

of s

cien

ce:

Con

cept

s—th

e co

ncep

t of t

he m

ole

deve

lope

d fro

m th

e re

late

d co

ncep

t of “

equi

vale

nt w

eigh

t” in

the

early

19t

h ce

ntur

y. (2

.3)

Und

erst

andi

ngs:

• Th

e m

ole

is a

fixe

d nu

mbe

r of p

artic

les

and

refe

rs to

the

amou

nt, n

, of

subs

tanc

e.

• M

asse

s of

ato

ms

are

com

pare

d on

a s

cale

rela

tive

to 12

C a

nd a

re e

xpre

ssed

as

rela

tive

atom

ic m

ass

(Ar)

and

rela

tive

form

ula/

mol

ecul

ar m

ass

(Mr).

• M

olar

mas

s (M

) has

the

units

g m

ol-1

.

• Th

e em

piric

al fo

rmul

a an

d m

olec

ular

form

ula

of a

com

poun

d gi

ve th

e si

mpl

est

ratio

and

the

actu

al n

umbe

r of a

tom

s pr

esen

t in

a m

olec

ule

resp

ectiv

ely.

App

licat

ions

and

ski

lls:

• C

alcu

latio

n of

the

mol

ar m

asse

s of

ato

ms,

ions

, mol

ecul

es a

nd fo

rmul

a un

its.

• S

olut

ion

of p

robl

ems

invo

lvin

g th

e re

latio

nshi

ps b

etw

een

the

num

ber o

f pa

rticl

es, t

he a

mou

nt o

f sub

stan

ce in

mol

es a

nd th

e m

ass

in g

ram

s.

• In

terc

onve

rsio

n of

the

perc

enta

ge c

ompo

sitio

n by

mas

s an

d th

e em

piric

al

form

ula.

• D

eter

min

atio

n of

the

mol

ecul

ar fo

rmul

a of

a c

ompo

und

from

its

empi

rical

fo

rmul

a an

d m

olar

mas

s.

• O

btai

ning

and

usi

ng e

xper

imen

tal d

ata

for d

eriv

ing

empi

rical

form

ulas

from

re

actio

ns in

volv

ing

mas

s ch

ange

s.

Inte

rnat

iona

l-min

dedn

ess:

• Th

e S

I sys

tem

(Sys

tèm

e In

tern

atio

nal d

’Uni

tés)

refe

rs to

the

met

ric s

yste

m o

f m

easu

rem

ent,

base

d on

sev

en b

ase

units

.

• Th

e In

tern

atio

nal B

urea

u of

Wei

ghts

and

Mea

sure

s (B

IPM

acc

ordi

ng to

its

Fren

ch in

itial

s) is

an

inte

rnat

iona

l sta

ndar

ds o

rgan

izat

ion,

whi

ch a

ims

to

ensu

re u

nifo

rmity

in th

e ap

plic

atio

n of

SI u

nits

aro

und

the

wor

ld.

Theo

ry o

f kno

wle

dge:

• Th

e m

agni

tude

of A

voga

dro’

s co

nsta

nt is

bey

ond

the

scal

e of

our

eve

ryda

y ex

perie

nce.

How

doe

s ou

r eve

ryda

y ex

perie

nce

limit

our i

ntui

tion?

Util

izat

ion:

• S

toic

hiom

etric

cal

cula

tions

are

fund

amen

tal t

o ch

emic

al p

roce

sses

in

rese

arch

and

indu

stry

, for

exa

mpl

e in

the

food

, med

ical

, pha

rmac

eutic

al a

nd

man

ufac

turin

g in

dust

ries.

• Th

e m

olar

vol

ume

for c

ryst

allin

e so

lids

is d

eter

min

ed b

y th

e te

chni

que

of X

-ra

y cr

ysta

llogr

aphy

.

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 2.

1—th

e sc

ale

of a

tom

s an

d th

eir c

ompo

nent

par

ticle

s

Topi

cs 4

.1, 4

.3 a

nd 4

.5—

latti

ce s

truct

ure

of io

nic

com

poun

ds, m

olec

ular

stru

ctur

e of

cov

alen

t com

poun

ds a

nd m

etal

lic la

ttice

To

pics

5.1

and

15.

2—st

anda

rd e

ntha

lpy

and

entro

py c

hang

es d

efin

ed p

er m

ole

Topi

c 19

.1—

mol

e ra

tios

of p

rodu

cts

in e

lect

roly

sis


Chemistry guide 35

1.2

The

mol

e co

ncep

t

Gui

danc

e:

• Th

e va

lue

of th

e A

voga

dro’

s co

nsta

nt (L

or N

A) is

giv

en in

the

data

boo

klet

in

sect

ion

2 an

d w

ill b

e gi

ven

for p

aper

1 q

uest

ions

.

• Th

e ge

nera

lly u

sed

unit

of m

olar

mas

s (g

mol

-1) is

a d

eriv

ed S

I uni

t.

Aim

s:

• A

im 6

: Exp

erim

ents

cou

ld in

clud

e pe

rcen

t mas

s of

hyd

rate

s, b

urni

ng o

f m

agne

sium

or c

alcu

latin

g A

voga

dro’

s nu

mbe

r.

• A

im 7

: Dat

a lo

gger

s ca

n be

use

d to

mea

sure

mas

s ch

ange

s du

ring

reac

tions

.


Chemistry guide36

Esse

ntia

l ide

a: M

ole

ratio

s in

che

mic

al e

quat

ions

can

be

used

to c

alcu

late

reac

ting

ratio

s by

mas

s an

d ga

s vo

lum

e.

1.3

Rea

ctin

g m

asse

s an

d vo

lum

es

Nat

ure

of s

cien

ce:

Mak

ing

care

ful o

bser

vatio

ns a

nd o

btai

ning

evi

denc

e fo

r sci

entif

ic th

eorie

s—A

voga

dro'

s in

itial

hyp

othe

sis.

(1.8

)

Und

erst

andi

ngs:

• R

eact

ants

can

be

eith

er li

miti

ng o

r exc

ess.

• Th

e ex

perim

enta

l yie

ld c

an b

e di

ffere

nt fr

om th

e th

eore

tical

yie

ld.

• A

voga

dro’

s la

w e

nabl

es th

e m

ole

ratio

of r

eact

ing

gase

s to

be

dete

rmin

ed

from

vol

umes

of t

he g

ases

.

• Th

e m

olar

vol

ume

of a

n id

eal g

as is

a c

onst

ant a

t spe

cifie

d te

mpe

ratu

re a

nd

pres

sure

.

• Th

e m

olar

con

cent

ratio

n of

a s

olut

ion

is d

eter

min

ed b

y th

e am

ount

of s

olut

e an

d th

e vo

lum

e of

sol

utio

n.

• A

sta

ndar

d so

lutio

n is

one

of k

now

n co

ncen

tratio

n.

App

licat

ions

and

ski

lls:

• S

olut

ion

of p

robl

ems

rela

ting

to re

actin

g qu

antit

ies,

lim

iting

and

exc

ess

reac

tant

s, th

eore

tical

, exp

erim

enta

l and

per

cent

age

yiel

ds.

• C

alcu

latio

n of

reac

ting

volu

mes

of g

ases

usi

ng A

voga

dro’

s la

w.

• S

olut

ion

of p

robl

ems

and

anal

ysis

of g

raph

s in

volv

ing

the

rela

tions

hip

betw

een

tem

pera

ture

, pre

ssur

e an

d vo

lum

e fo

r a fi

xed

mas

s of

an

idea

l gas

.

• S

olut

ion

of p

robl

ems

rela

ting

to th

e id

eal g

as e

quat

ion.

Inte

rnat

iona

l-min

dedn

ess:

• Th

e S

I uni

t of p

ress

ure

is th

e P

asca

l (P

a), N

m-2

, but

man

y ot

her u

nits

rem

ain

in c

omm

on u

sage

in d

iffer

ent c

ount

ries.

The

se in

clud

e at

mos

pher

e (a

tm),

mill

imet

res

of m

ercu

ry (m

m H

g), T

orr,

bar a

nd p

ound

s pe

r squ

are

inch

(psi

). Th

e ba

r (10

5 Pa)

is n

ow w

idel

y us

ed a

s a

conv

enie

nt u

nit,

as it

is v

ery

clos

e to

1

atm

. The

SI u

nit f

or v

olum

e is

m3 ,

alth

ough

litre

is a

com

mon

ly u

sed

unit.

Theo

ry o

f kno

wle

dge:

• A

ssig

ning

num

bers

to th

e m

asse

s of

the

chem

ical

ele

men

ts h

as a

llow

ed

chem

istry

to d

evel

op in

to a

phy

sica

l sci

ence

. Why

is m

athe

mat

ics

so e

ffect

ive

in d

escr

ibin

g th

e na

tura

l wor

ld?

• Th

e id

eal g

as e

quat

ion

can

be d

educ

ed fr

om a

sm

all n

umbe

r of a

ssum

ptio

ns

of id

eal b

ehav

iour

. Wha

t is

the

role

of r

easo

n, p

erce

ptio

n, in

tuiti

on a

nd

imag

inat

ion

in th

e de

velo

pmen

t of s

cien

tific

mod

els?

Util

izat

ion:

• G

as v

olum

e ch

ange

s du

ring

chem

ical

reac

tions

are

resp

onsi

ble

for t

he

infla

tion

of a

ir ba

gs in

veh

icle

s an

d ar

e th

e ba

sis

of m

any

othe

r exp

losi

ve

reac

tions

, suc

h as

the

deco

mpo

sitio

n of

TN

T (tr

initr

otol

uene

).

• Th

e co

ncep

t of p

erce

ntag

e yi

eld

is v

ital i

n m

onito

ring

the

effic

ienc

y of

in

dust

rial p

roce

sses

.

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 4.

4—in

term

olec

ular

forc

es

Topi

c 5.

1—ca

lcul

atio

ns o

f mol

ar e

ntha

lpy

chan

ges


Chemistry guide 37

1.3

Rea

ctin

g m

asse

s an

d vo

lum

es

• E

xpla

natio

n of

the

devi

atio

n of

real

gas

es fr

om id

eal b

ehav

iour

at l

ow

tem

pera

ture

and

hig

h pr

essu

re.

• O

btai

ning

and

usi

ng e

xper

imen

tal v

alue

s to

cal

cula

te th

e m

olar

mas

s of

a g

as

from

the

idea

l gas

equ

atio

n.

• S

olut

ion

of p

robl

ems

invo

lvin

g m

olar

con

cent

ratio

n, a

mou

nt o

f sol

ute

and

volu

me

of s

olut

ion.

• U

se o

f the

exp

erim

enta

l met

hod

of ti

tratio

n to

cal

cula

te th

e co

ncen

tratio

n of

a

solu

tion

by re

fere

nce

to a

sta

ndar

d so

lutio

n.

Gui

danc

e:

• V

alue

s fo

r the

mol

ar v

olum

e of

an

idea

l gas

are

giv

en in

the

data

boo

klet

in

sect

ion

2.

• Th

e id

eal g

as e

quat

ion,

𝑃𝑃𝑃𝑃=𝑛𝑛𝑛𝑛

𝑛𝑛 , a

nd th

e va

lue

of th

e ga

s co

nsta

nt (R

) are

gi

ven

in th

e da

ta b

ookl

et in

sec

tions

1 a

nd 2

.

• U

nits

of c

once

ntra

tion

to in

clud

e: g

dm

-3, m

ol d

m-3

and

par

ts p

er m

illio

n (p

pm).

• Th

e us

e of

squ

are

brac

kets

to d

enot

e m

olar

con

cent

ratio

n is

requ

ired.

Topi

c 9.

1—re

dox

titra

tions

To

pic

17.1

—eq

uilib

rium

cal

cula

tions

To

pic

18.2

—ac

id-b

ase

titra

tions

To

pic

21.1

and

A.8

—X-

ray

crys

tallo

grap

hy

Phy

sics

topi

c 3.

2—Id

eal g

as la

w

Aim

s:

• A

im 6

: Exp

erim

enta

l des

ign

coul

d in

clud

e ex

cess

and

lim

iting

reac

tant

s.

Exp

erim

ents

cou

ld in

clud

e gr

avim

etric

det

erm

inat

ion

by p

reci

pita

tion

of a

n in

solu

ble

salt.

• A

im 7

: Dat

a lo

gger

s ca

n be

use

d to

mea

sure

tem

pera

ture

, pre

ssur

e an

d vo

lum

e ch

ange

s in

reac

tions

or t

o de

term

ine

the

valu

e of

the

gas

cons

tant

, R.

• A

im 8

: The

uni

t par

ts p

er m

illio

n, p

pm, i

s co

mm

only

use

d in

mea

surin

g sm

all

leve

ls o

f pol

luta

nts

in fl

uids

. Thi

s un

it is

con

veni

ent f

or c

omm

unic

atin

g ve

ry

low

con

cent

ratio

ns, b

ut is

not

a fo

rmal

SI u

nit.

Topic 2: Atomic structure

Chemistry guide38

Esse

ntia

l ide

a: T

he m

ass

of a

n at

om is

con

cent

rate

d in

its

min

ute,

pos

itive

ly c

harg

ed n

ucle

us.

2.1

The

nucl

ear a

tom

Nat

ure

of s

cien

ce:

Evi

denc

e an

d im

prov

emen

ts in

inst

rum

enta

tion—

alph

a pa

rticl

es w

ere

used

in th

e de

velo

pmen

t of t

he n

ucle

ar m

odel

of t

he a

tom

that

was

firs

t pro

pose

d by

Rut

herfo

rd.

(1.8

)

Par

adig

m s

hifts

—th

e su

bato

mic

par

ticle

theo

ry o

f mat

ter r

epre

sent

s a

para

digm

shi

ft in

sci

ence

that

occ

urre

d in

the

late

180

0s. (

2.3)

Und

erst

andi

ngs:

• A

tom

s co

ntai

n a

posi

tivel

y ch

arge

d de

nse

nucl

eus

com

pose

d of

pro

tons

and

ne

utro

ns (n

ucle

ons)

.

• N

egat

ivel

y ch

arge

d el

ectro

ns o

ccup

y th

e sp

ace

outs

ide

the

nucl

eus.

• Th

e m

ass

spec

trom

eter

is u

sed

to d

eter

min

e th

e re

lativ

e at

omic

mas

s of

an

elem

ent f

rom

its

isot

opic

com

posi

tion.

App

licat

ions

and

ski

lls:

• U

se o

f the

nuc

lear

sym

bol n

otat

ion

𝑋𝑋 𝑍𝑍𝐴𝐴 to

ded

uce

the

num

ber o

f pro

tons

, ne

utro

ns a

nd e

lect

rons

in a

tom

s an

d io

ns.

• C

alcu

latio

ns in

volv

ing

non-

inte

ger r

elat

ive

atom

ic m

asse

s an

d ab

unda

nce

of

isot

opes

from

giv

en d

ata,

incl

udin

g m

ass

spec

tra.

Gui

danc

e:

• R

elat

ive

mas

ses

and

char

ges

of th

e su

bato

mic

par

ticle

s sh

ould

be

know

n,

actu

al v

alue

s ar

e gi

ven

in s

ectio

n 4

of th

e da

ta b

ookl

et. T

he m

ass

of th

e el

ectro

n ca

n be

con

side

red

negl

igib

le.

• S

peci

fic e

xam

ples

of i

soto

pes

need

not

be

lear

ned.

• Th

e op

erat

ion

of th

e m

ass

spec

trom

eter

is n

ot re

quire

d.

Inte

rnat

iona

l-min

dedn

ess:

• Is

otop

e en

richm

ent u

ses

phys

ical

pro

perti

es to

sep

arat

e is

otop

es o

f ura

nium

, an

d is

em

ploy

ed in

man

y co

untri

es a

s pa

rt of

nuc

lear

ene

rgy

and

wea

ponr

y pr

ogra

mm

es.

Theo

ry o

f kno

wle

dge:

• R

icha

rd F

eynm

an: “

If al

l of s

cien

tific

kno

wle

dge

wer

e to

be

dest

roye

d an

d on

ly o

ne s

ente

nce

pass

ed o

n to

the

next

gen

erat

ion,

I be

lieve

it is

that

all

thin

gs a

re m

ade

of a

tom

s.” A

re th

e m

odel

s an

d th

eorie

s w

hich

sci

entis

ts

crea

te a

ccur

ate

desc

riptio

ns o

f the

nat

ural

wor

ld, o

r are

they

prim

arily

use

ful

inte

rpre

tatio

ns fo

r pre

dict

ion,

exp

lana

tion

and

cont

rol o

f the

nat

ural

wor

ld?

• N

o su

bato

mic

par

ticle

s ca

n be

(or w

ill b

e) d

irect

ly o

bser

ved.

Whi

ch w

ays

of

know

ing

do w

e us

e to

inte

rpre

t ind

irect

evi

denc

e, g

aine

d th

roug

h th

e us

e of

te

chno

logy

?

Util

izat

ion:

• R

adio

isot

opes

are

use

d in

nuc

lear

med

icin

e fo

r dia

gnos

tics,

trea

tmen

t and

re

sear

ch, a

s tra

cers

in b

ioch

emic

al a

nd p

harm

aceu

tical

rese

arch

, and

as

“che

mic

al c

lock

s” in

geo

logi

cal a

nd a

rcha

eolo

gica

l dat

ing.

• P

ET

(pos

itron

em

issi

on to

mog

raph

y) s

cann

ers

give

thre

e-di

men

sion

al im

ages

of

trac

er c

once

ntra

tion

in th

e bo

dy, a

nd c

an b

e us

ed to

det

ect c

ance

rs.

Topi

c 2:

Ato

mic

str

uctu

re

6 ho

urs

Core


Chemistry guide 39

2.1

The

nucl

ear a

tom

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

cs 1

1.3,

21.

1 an

d op

tions

D.8

and

D.9

—N

MR

O

ptio

ns C

.3 a

nd C

.7—

nucl

ear f

issi

on

Opt

ion

D.8

—nu

clea

r med

icin

e

Aim

s:

• A

im 7

: Sim

ulat

ions

of R

uthe

rford

’s g

old

foil

expe

rimen

t can

be

unde

rtake

n.

• A

im 8

: Rad

ionu

clid

es c

arry

dan

gers

to h

ealth

due

to th

eir i

oniz

ing

effe

cts

on

cells

.


Chemistry guide40

Esse

ntia

l ide

a: T

he e

lect

ron

conf

igur

atio

n of

an

atom

can

be

dedu

ced

from

its

atom

ic n

umbe

r.

2.2

Elec

tron

con

figur

atio

n

Nat

ure

of s

cien

ce:

Dev

elop

men

ts in

sci

entif

ic re

sear

ch fo

llow

impr

ovem

ents

in a

ppar

atus

—th

e us

e of

ele

ctric

ity a

nd m

agne

tism

in T

hom

son’

s ca

thod

e ra

ys.(1

.8)

Theo

ries

bein

g su

pers

eded

—qu

antu

m m

echa

nics

is a

mon

g th

e m

ost c

urre

nt m

odel

s of

the

atom

. (1.

9)

Use

theo

ries

to e

xpla

in n

atur

al p

heno

men

a—lin

e sp

ectra

exp

lain

ed b

y th

e Bo

hr m

odel

of t

he a

tom

. (2.

2)

Und

erst

andi

ngs:

• Em

issi

on s

pect

ra a

re p

rodu

ced

whe

n ph

oton

s ar

e em

itted

from

ato

ms

as

exci

ted

elec

trons

retu

rn to

a lo

wer

ene

rgy

leve

l.

• Th

e lin

e em

issi

on s

pect

rum

of h

ydro

gen

prov

ides

evi

denc

e fo

r the

exi

sten

ce

of e

lect

rons

in d

iscr

ete

ener

gy le

vels

, whi

ch c

onve

rge

at h

ighe

r ene

rgie

s.

• Th

e m

ain

ener

gy le

vel o

r she

ll is

giv

en a

n in

tege

r num

ber,

n, a

nd c

an h

old

a m

axim

um n

umbe

r of e

lect

rons

, 2n2 .

• A

mor

e de

taile

d m

odel

of t

he a

tom

des

crib

es th

e di

visi

on o

f the

mai

n en

ergy

le

vel i

nto

s, p

, d a

nd f

sub-

leve

ls o

f suc

cess

ivel

y hi

gher

ene

rgie

s.

• Su

b-le

vels

con

tain

a fi

xed

num

ber o

f orb

itals

, reg

ions

of s

pace

whe

re th

ere

is

a hi

gh p

roba

bilit

y of

find

ing

an e

lect

ron.

• Ea

ch o

rbita

l has

a d

efin

ed e

nerg

y st

ate

for a

giv

en e

lect

roni

c co

nfig

urat

ion

and

chem

ical

env

ironm

ent a

nd c

an h

old

two

elec

trons

of o

ppos

ite s

pin.

App

licat

ions

and

ski

lls:

• D

escr

iptio

n of

the

rela

tions

hip

betw

een

colo

ur, w

avel

engt

h, fr

eque

ncy

and

ener

gy a

cros

s th

e el

ectro

mag

netic

spe

ctru

m.

• D

istin

ctio

n be

twee

n a

cont

inuo

us s

pect

rum

and

a li

ne s

pect

rum

.

Inte

rnat

iona

l-min

dedn

ess:

• Th

e Eu

rope

an O

rgan

izat

ion

for N

ucle

ar R

esea

rch

(CER

N) i

s ru

n by

its

Euro

pean

mem

ber s

tate

s (2

0 st

ates

in 2

013)

, with

invo

lvem

ents

from

sc

ient

ists

from

man

y ot

her c

ount

ries.

It o

pera

tes

the

wor

ld’s

larg

est p

artic

le

phys

ics

rese

arch

cen

tre, i

nclu

ding

par

ticle

acc

eler

ator

s an

d de

tect

ors

used

to

stud

y th

e fu

ndam

enta

l con

stitu

ents

of m

atte

r.

Theo

ry o

f kno

wle

dge:

• H

eise

nber

g’s

Unc

erta

inty

Prin

cipl

e st

ates

that

ther

e is

a th

eore

tical

lim

it to

the

prec

isio

n w

ith w

hich

we

can

know

the

mom

entu

m a

nd th

e po

sitio

n of

a

parti

cle.

Wha

t are

the

impl

icat

ions

of t

his

for t

he li

mits

of h

uman

kno

wle

dge?

• “O

ne a

im o

f the

phy

sica

l sci

ence

s ha

s be

en to

giv

e an

exa

ct p

ictu

re o

f the

m

ater

ial w

orld

. One

ach

ieve

men

t ...

has

been

to p

rove

that

this

aim

is

unat

tain

able

.” —

Jaco

b Br

onow

ski.

Wha

t are

the

impl

icat

ions

of t

his

clai

m fo

r th

e as

pira

tions

of n

atur

al s

cien

ces

in p

artic

ular

and

for k

now

ledg

e in

gen

eral

?

Util

izat

ion:

• Ab

sorp

tion

and

emis

sion

spe

ctra

are

wid

ely

used

in a

stro

nom

y to

ana

lyse

lig

ht fr

om s

tars

.

• At

omic

abs

orpt

ion

spec

trosc

opy

is a

ver

y se

nsiti

ve m

eans

of d

eter

min

ing

the

pres

ence

and

con

cent

ratio

n of

met

allic

ele

men

ts.


Chemistry guide 41

2.2

Elec

tron

con

figur

atio

n

• D

escr

iptio

n of

the

emis

sion

spe

ctru

m o

f the

hyd

roge

n at

om, i

nclu

ding

the

rela

tions

hips

bet

wee

n th

e lin

es a

nd e

nerg

y tra

nsiti

ons

to th

e fir

st, s

econ

d an

d th

ird e

nerg

y le

vels

.

• R

ecog

nitio

n of

the

shap

e of

an

s at

omic

orb

ital a

nd th

e p x

, py a

nd p

z at

omic

or

bita

ls.

• A

pplic

atio

n of

the

Auf

bau

prin

cipl

e, H

und’

s ru

le a

nd th

e Pa

uli e

xclu

sion

pr

inci

ple

to w

rite

elec

tron

conf

igur

atio

ns fo

r ato

ms

and

ions

up

to Z

= 3

6.

Gui

danc

e:

• D

etai

ls o

f the

ele

ctro

mag

netic

spe

ctru

m a

re g

iven

in th

e da

ta b

ookl

et in

se

ctio

n 3.

• Th

e na

mes

of t

he d

iffer

ent s

erie

s in

the

hydr

ogen

line

em

issi

on s

pect

rum

are

no

t req

uire

d.

• Fu

ll el

ectro

n co

nfig

urat

ions

(eg

1s2 2

s2 2p6 3

s2 3p4 )

and

con

dens

ed e

lect

ron

conf

igur

atio

ns (e

g [N

e] 3

s2 3p4 )

sho

uld

be c

over

ed.

Orb

ital d

iagr

ams

shou

ld b

e us

ed to

repr

esen

t the

cha

ract

er a

nd re

lativ

e en

ergy

of

orbi

tals

. Orb

ital d

iagr

ams

refe

r to

arro

w-in

-box

dia

gram

s, s

uch

as th

e on

e gi

ven

belo

w.

• Th

e el

ectro

n co

nfig

urat

ions

of C

r and

Cu

as e

xcep

tions

sho

uld

be c

over

ed.

• Fi

rew

orks

—em

issi

on s

pect

ra.

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

cs 3

.1 a

nd 3

.2—

perio

dici

ty

Topi

c 4.

1—de

duct

ion

of fo

rmul

ae o

f ion

ic c

ompo

unds

To

pic

6.1—

Max

wel

l–B

oltz

man

n di

strib

utio

n as

a p

roba

bilit

y de

nsity

func

tion

Phy

sics

topi

c 7.

1 an

d op

tion

D.2

—st

ella

r cha

ract

eris

tics

Aim

s:

• A

im 6

: Em

issi

on s

pect

ra c

ould

be

obse

rved

usi

ng d

isch

arge

tube

s of

diff

eren

t ga

ses

and

a sp

ectro

scop

e. F

lam

e te

sts

coul

d be

use

d to

stu

dy s

pect

ra.

Topic 3: Periodicity

Chemistry guide42

Esse

ntia

l ide

a: T

he a

rran

gem

ent o

f ele

men

ts in

the

perio

dic

tabl

e he

lps

to p

redi

ct th

eir e

lect

ron

conf

igur

atio

n.

3.1

Perio

dic

tabl

e

Nat

ure

of s

cien

ce:

Obt

ain

evid

ence

for s

cien

tific

theo

ries

by m

akin

g an

d te

stin

g pr

edic

tions

bas

ed o

n th

em—

scie

ntis

ts o

rgan

ize

subj

ects

bas

ed o

n st

ruct

ure

and

func

tion;

the

perio

dic

tabl

e is

a

key

exam

ple

of th

is. E

arly

mod

els

of th

e pe

riodi

c ta

ble

from

Men

dele

ev, a

nd la

ter M

osel

ey, a

llow

ed fo

r the

pre

dict

ion

of p

rope

rties

of e

lem

ents

that

had

not

yet

bee

n di

scov

ered

. (1.

9)

Und

erst

andi

ngs:

• Th

e pe

riodi

c ta

ble

is a

rrang

ed in

to fo

ur b

lock

s as

soci

ated

with

the

four

sub

-le

vels

—s,

p, d

, and

f.

• Th

e pe

riodi

c ta

ble

cons

ists

of g

roup

s (v

ertic

al c

olum

ns) a

nd p

erio

ds (h

oriz

onta

l ro

ws)

.

• Th

e pe

riod

num

ber (

n) is

the

oute

r ene

rgy

leve

l tha

t is

occu

pied

by

elec

trons

.

• Th

e nu

mbe

r of t

he p

rinci

pal e

nerg

y le

vel a

nd th

e nu

mbe

r of t

he v

alen

ce

elec

trons

in a

n at

om c

an b

e de

duce

d fro

m it

s po

sitio

n on

the

perio

dic

tabl

e.

• Th

e pe

riodi

c ta

ble

show

s th

e po

sitio

ns o

f met

als,

non

-met

als

and

met

allo

ids.

App

licat

ions

and

ski

lls:

• D

educ

tion

of th

e el

ectro

n co

nfig

urat

ion

of a

n at

om fr

om th

e el

emen

t’s p

ositi

on

on th

e pe

riodi

c ta

ble,

and

vic

e ve

rsa.

Gui

danc

e:

• Th

e te

rms

alka

li m

etal

s, h

alog

ens,

nob

le g

ases

, tra

nsiti

on m

etal

s, la

ntha

noid

s an

d ac

tinoi

ds s

houl

d be

kno

wn.

• Th

e gr

oup

num

berin

g sc

hem

e fro

m g

roup

1 to

gro

up 1

8, a

s re

com

men

ded

by

IUP

AC

, sho

uld

be u

sed.

Inte

rnat

iona

l-min

dedn

ess:

• Th

e de

velo

pmen

t of t

he p

erio

dic

tabl

e to

ok m

any

year

s an

d in

volv

ed s

cien

tists

fro

m d

iffer

ent c

ount

ries

build

ing

upon

the

foun

datio

ns o

f eac

h ot

her’s

wor

k an

d id

eas.

Theo

ry o

f kno

wle

dge:

• W

hat r

ole

did

indu

ctiv

e an

d de

duct

ive

reas

onin

g pl

ay in

the

deve

lopm

ent o

f the

pe

riodi

c ta

ble?

Wha

t rol

e do

es in

duct

ive

and

dedu

ctiv

e re

ason

ing

have

in

scie

nce

in g

ener

al?

Util

izat

ion:

• O

ther

sci

entif

ic s

ubje

cts

also

use

the

perio

dic

tabl

e to

und

erst

and

the

stru

ctur

e an

d re

activ

ity o

f ele

men

ts a

s it

appl

ies

to th

eir o

wn

disc

iplin

es.

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 2.

2—el

ectro

n co

nfig

urat

ion

Aim

s:

• A

im 3

: App

ly th

e or

gani

zatio

n of

the

perio

dic

tabl

e to

und

erst

and

gene

ral

trend

s in

pro

perti

es.

• A

im 4

: Be

able

to a

naly

se d

ata

to e

xpla

in th

e or

gani

zatio

n of

the

elem

ents

.

• A

im 6

: Be

able

to re

cogn

ize

phys

ical

sam

ples

or i

mag

es o

f com

mon

ele

men

ts.

Topi

c 3:

Per

iodi

city

6

hour

s

Core

Topic 3: Periodicity

Chemistry guide 43

Esse

ntia

l ide

a: E

lem

ents

sho

w tr

ends

in th

eir p

hysi

cal a

nd c

hem

ical

pro

perti

es a

cros

s pe

riods

and

dow

n gr

oups

.

3.2

Perio

dic

tren

ds

Nat

ure

of s

cien

ce:

Look

ing

for p

atte

rns—

the

posi

tion

of a

n el

emen

t in

the

perio

dic

tabl

e al

low

s sc

ient

ists

to m

ake

accu

rate

pre

dict

ions

of i

ts p

hysi

cal a

nd c

hem

ical

pro

perti

es. T

his

give

s sc

ient

ists

the

abili

ty to

syn

thes

ize

new

sub

stan

ces

base

d on

the

expe

cted

reac

tivity

of e

lem

ents

. (3.

1)

Und

erst

andi

ngs:

• V

ertic

al a

nd h

oriz

onta

l tre

nds

in th

e pe

riodi

c ta

ble

exis

t for

ato

mic

radi

us, i

onic

ra

dius

, ion

izat

ion

ener

gy, e

lect

ron

affin

ity a

nd e

lect

rone

gativ

ity.

• Tr

ends

in m

etal

lic a

nd n

on-m

etal

lic b

ehav

iour

are

due

to th

e tre

nds

abov

e.

• O

xide

s ch

ange

from

bas

ic th

roug

h am

phot

eric

to a

cidi

c ac

ross

a p

erio

d.

App

licat

ions

and

ski

lls:

• P

redi

ctio

n an

d ex

plan

atio

n of

the

met

allic

and

non

-met

allic

beh

avio

ur o

f an

elem

ent b

ased

on

its p

ositi

on in

the

perio

dic

tabl

e.

• D

iscu

ssio

n of

the

sim

ilarit

ies

and

diffe

renc

es in

the

prop

ertie

s of

ele

men

ts in

th

e sa

me

grou

p, w

ith re

fere

nce

to a

lkal

i met

als

(gro

up 1

) and

hal

ogen

s (g

roup

17

).

• C

onst

ruct

ion

of e

quat

ions

to e

xpla

in th

e pH

cha

nges

for r

eact

ions

of N

a 2O

, M

gO, P

4O10

, and

the

oxid

es o

f nitr

ogen

and

sul

fur w

ith w

ater

.

Gui

danc

e:

• O

nly

exam

ples

of g

ener

al tr

ends

acr

oss

perio

ds a

nd d

own

grou

ps a

re re

quire

d.

For i

oniz

atio

n en

ergy

the

disc

ontin

uitie

s in

the

incr

ease

acr

oss

a pe

riod

shou

ld

be c

over

ed.

• G

roup

tren

ds s

houl

d in

clud

e th

e tre

atm

ent o

f the

reac

tions

of a

lkal

i met

als

with

w

ater

, alk

ali m

etal

s w

ith h

alog

ens

and

halo

gens

with

hal

ide

ions

.

Inte

rnat

iona

l-min

dedn

ess:

• In

dust

rializ

atio

n ha

s le

d to

the

prod

uctio

n of

man

y pr

oduc

ts th

at c

ause

glo

bal

prob

lem

s w

hen

rele

ased

into

the

envi

ronm

ent.

Theo

ry o

f kno

wle

dge:

• Th

e pr

edic

tive

pow

er o

f Men

dele

ev’s

Per

iodi

c Ta

ble

illus

trate

s th

e “ri

sk-ta

king

” na

ture

of s

cien

ce. W

hat i

s th

e de

mar

catio

n be

twee

n sc

ient

ific

and

pseu

dosc

ient

ific

clai

ms?

• Th

e P

erio

dic

Tabl

e is

an

exce

llent

exa

mpl

e of

cla

ssifi

catio

n in

sci

ence

. How

do

es c

lass

ifica

tion

and

cate

goriz

atio

n he

lp a

nd h

inde

r the

pur

suit

of

know

ledg

e?

Util

izat

ion:

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 2.

2—an

omal

ies

in fi

rst i

oniz

atio

n en

ergy

val

ues

can

be c

onne

cted

to s

tabi

lity

in e

lect

ron

conf

igur

atio

n

Topi

c 8.

5—pr

oduc

tion

of a

cid

rain

Aim

s:

• A

ims

1 an

d 8:

Wha

t is

the

glob

al im

pact

of a

cid

depo

sitio

n?

• A

im 6

: Exp

erim

ent w

ith c

hem

ical

tren

ds d

irect

ly in

the

labo

rato

ry o

r thr

ough

the

use

of te

ache

r dem

onst

ratio

ns.

• A

im 6

: The

use

of t

rans

ition

met

al io

ns a

s ca

taly

sts

coul

d be

inve

stig

ated

.

• A

im 7

: Per

iodi

c tre

nds

can

be s

tudi

ed w

ith th

e us

e of

com

pute

r dat

abas

es.

Topic 4: Chemical bonding and structure

Chemistry guide44

Esse

ntia

l ide

a: Io

nic

com

poun

ds c

onsi

st o

f ion

s he

ld to

geth

er in

latti

ce s

truct

ures

by

ioni

c bo

nds.

4.1

Ioni

c bo

ndin

g an

d st

ruct

ure

Nat

ure

of s

cien

ce:

Use

theo

ries

to e

xpla

in n

atur

al p

heno

men

a—m

olte

n io

nic

com

poun

ds c

ondu

ct e

lect

ricity

but

sol

id io

nic

com

poun

ds d

o no

t. Th

e so

lubi

lity

and

mel

ting

poin

ts o

f ion

ic

com

poun

ds c

an b

e us

ed to

exp

lain

obs

erva

tions

. (2.

2)

Und

erst

andi

ngs:

• P

ositi

ve io

ns (c

atio

ns) f

orm

by

met

als

losi

ng v

alen

ce e

lect

rons

.

• N

egat

ive

ions

(ani

ons)

form

by

non-

met

als

gain

ing

elec

trons

.

• Th

e nu

mbe

r of e

lect

rons

lost

or g

aine

d is

det

erm

ined

by

the

elec

tron

conf

igur

atio

n of

the

atom

.

• Th

e io

nic

bond

is d

ue to

ele

ctro

stat

ic a

ttrac

tion

betw

een

oppo

site

ly c

harg

ed

ions

.

• U

nder

nor

mal

con

ditio

ns, i

onic

com

poun

ds a

re u

sual

ly s

olid

s w

ith la

ttice

st

ruct

ures

.

App

licat

ions

and

ski

lls:

• D

educ

tion

of th

e fo

rmul

a an

d na

me

of a

n io

nic

com

poun

d fro

m it

s co

mpo

nent

io

ns, i

nclu

ding

pol

yato

mic

ions

.

• E

xpla

natio

n of

the

phys

ical

pro

perti

es o

f ion

ic c

ompo

unds

(vol

atili

ty, e

lect

rical

co

nduc

tivity

and

sol

ubili

ty) i

n te

rms

of th

eir s

truct

ure.

Gui

danc

e:

• S

tude

nts

shou

ld b

e fa

mili

ar w

ith th

e na

mes

of t

hese

pol

yato

mic

ions

: NH

4+ ,

OH

- , N

O3- ,

HC

O3- ,

CO

32-, S

O42-

and

PO

43-.

Theo

ry o

f kno

wle

dge:

• G

ener

al ru

les

in c

hem

istry

(lik

e th

e oc

tet r

ule)

ofte

n ha

ve e

xcep

tions

. How

m

any

exce

ptio

ns h

ave

to e

xist

for a

rule

to c

ease

to b

e us

eful

?

• W

hat e

vide

nce

do y

ou h

ave

for t

he e

xist

ence

of i

ons?

Wha

t is

the

diffe

renc

e be

twee

n di

rect

and

indi

rect

evi

denc

e?

Util

izat

ion:

• Io

nic

liqui

ds a

re e

ffici

ent s

olve

nts

and

elec

troly

tes

used

in e

lect

ric p

ower

so

urce

s an

d gr

een

indu

stria

l pro

cess

es.

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 3.

2—pe

riodi

c tre

nds

Topi

c 21

.1 a

nd O

ptio

n A

.8—

use

of X

-ray

crys

tallo

grap

hy in

stru

ctur

al d

eter

min

atio

ns

Phy

sics

topi

c 5.

1—el

ectro

stat

ics

Aim

s:

• A

im 3

: Use

nam

ing

conv

entio

ns to

nam

e io

nic

com

poun

ds.

• A

im 6

: Stu

dent

s co

uld

inve

stig

ate

com

poun

ds b

ased

on

thei

r bon

d ty

pe a

nd

prop

ertie

s or

obt

ain

sodi

um c

hlor

ide

by s

olar

eva

pora

tion.

• A

im 7

: Com

pute

r sim

ulat

ion

coul

d be

use

d to

obs

erve

cry

stal

latti

ce s

truct

ures

.

Topi

c 4:

Che

mic

al b

ondi

ng a

nd s

truc

ture

13

.5 h

ours

Core


Chemistry guide 45

Esse

ntia

l ide

a: C

oval

ent c

ompo

unds

form

by

the

shar

ing

of e

lect

rons

.

4.2.

Cov

alen

t bon

ding

Nat

ure

of s

cien

ce:

Look

ing

for t

rend

s an

d di

scre

panc

ies—

com

poun

ds c

onta

inin

g no

n-m

etal

s ha

ve d

iffer

ent p

rope

rties

than

com

poun

ds th

at c

onta

in n

on-m

etal

s an

d m

etal

s. (2

.5)

Use

theo

ries

to e

xpla

in n

atur

al p

heno

men

a—Le

wis

intro

duce

d a

clas

s of

com

poun

ds w

hich

sha

re e

lect

rons

. Pau

ling

used

the

idea

of e

lect

rone

gativ

ity to

exp

lain

une

qual

sh

arin

g of

ele

ctro

ns. (

2.2)

Und

erst

andi

ngs:

• A

cov

alen

t bon

d is

form

ed b

y th

e el

ectro

stat

ic a

ttrac

tion

betw

een

a sh

ared

pai

r of

ele

ctro

ns a

nd th

e po

sitiv

ely

char

ged

nucl

ei.

• S

ingl

e, d

oubl

e an

d tri

ple

cova

lent

bon

ds in

volv

e on

e, tw

o an

d th

ree

shar

ed

pairs

of e

lect

rons

resp

ectiv

ely.

• B

ond

leng

th d

ecre

ases

and

bon

d st

reng

th in

crea

ses

as th

e nu

mbe

r of s

hare

d el

ectro

ns in

crea

ses.

• B

ond

pola

rity

resu

lts fr

om th

e di

ffere

nce

in e

lect

rone

gativ

ities

of t

he b

onde

d at

oms.

App

licat

ions

and

ski

lls:

• D

educ

tion

of th

e po

lar n

atur

e of

a c

oval

ent b

ond

from

ele

ctro

nega

tivity

val

ues.

Gui

danc

e:

• B

ond

pola

rity

can

be s

how

n ei

ther

with

par

tial c

harg

es, d

ipol

es o

r vec

tors

.

• E

lect

rone

gativ

ity v

alue

s ar

e gi

ven

in th

e da

ta b

ookl

et in

sec

tion

8.

Util

izat

ion:

• M

icro

wav

es—

cook

ing

with

pol

ar m

olec

ules

.

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 10

.1—

orga

nic

mol

ecul

es

Aim

s:

• A

im 3

: Use

nam

ing

conv

entio

ns to

nam

e co

vale

ntly

bon

ded

com

poun

ds.


Chemistry guide46

Esse

ntia

l ide

a: L

ewis

(ele

ctro

n do

t) st

ruct

ures

sho

w th

e el

ectro

n do

mai

ns in

the

vale

nce

shel

l and

are

use

d to

pre

dict

mol

ecul

ar s

hape

.

4.3

Cov

alen

t str

uctu

res

Nat

ure

of s

cien

ce:

Sci

entis

ts u

se m

odel

s as

repr

esen

tatio

ns o

f the

real

wor

ld—

the

deve

lopm

ent o

f the

mod

el o

f mol

ecul

ar s

hape

(VS

EPR

) to

expl

ain

obse

rvab

le p

rope

rties

. (1.

10)

Und

erst

andi

ngs:

• Le

wis

(ele

ctro

n do

t) st

ruct

ures

sho

w a

ll th

e va

lenc

e el

ectro

ns in

a c

oval

ently

bo

nded

spe

cies

.

• Th

e “o

ctet

rule

” ref

ers

to th

e te

nden

cy o

f ato

ms

to g

ain

a va

lenc

e sh

ell w

ith a

to

tal o

f 8 e

lect

rons

.

• S

ome

atom

s, li

ke B

e an

d B

, mig

ht fo

rm s

tabl

e co

mpo

unds

with

inco

mpl

ete

octe

ts o

f ele

ctro

ns.

• R

eson

ance

stru

ctur

es o

ccur

whe

n th

ere

is m

ore

than

one

pos

sibl

e po

sitio

n fo

r a

doub

le b

ond

in a

mol

ecul

e.

• S

hape

s of

spe

cies

are

det

erm

ined

by

the

repu

lsio

n of

ele

ctro

n pa

irs a

ccor

ding

to

VS

EP

R th

eory

.

• C

arbo

n an

d si

licon

form

gia

nt c

oval

ent/n

etw

ork

cova

lent

stru

ctur

es.

App

licat

ions

and

ski

lls:

• D

educ

tion

of L

ewis

(ele

ctro

n do

t) st

ruct

ure

of m

olec

ules

and

ions

sho

win

g al

l va

lenc

e el

ectro

ns fo

r up

to fo

ur e

lect

ron

pairs

on

each

ato

m.

• Th

e us

e of

VS

EPR

theo

ry to

pre

dict

the

elec

tron

dom

ain

geom

etry

and

the

mol

ecul

ar g

eom

etry

for s

peci

es w

ith tw

o, th

ree

and

four

ele

ctro

n do

mai

ns.

• P

redi

ctio

n of

bon

d an

gles

from

mol

ecul

ar g

eom

etry

and

pre

senc

e of

non

-bo

ndin

g pa

irs o

f ele

ctro

ns.

• P

redi

ctio

n of

mol

ecul

ar p

olar

ity fr

om b

ond

pola

rity

and

mol

ecul

ar g

eom

etry

.

• D

educ

tion

of re

sona

nce

stru

ctur

es, e

xam

ples

incl

ude

but a

re n

ot li

mite

d to

C

6H6,

CO

32- a

nd O

3.

Theo

ry o

f kno

wle

dge:

• D

oes

the

need

for r

eson

ance

stru

ctur

es d

ecre

ase

the

valu

e or

val

idity

of L

ewis

(e

lect

ron

dot)

theo

ry?

Wha

t crit

eria

do

we

use

in a

sses

sing

the

valid

ity o

f a

scie

ntifi

c th

eory

?

Util

izat

ion:

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Opt

ion

A.7

—bi

odeg

rada

bilit

y of

pla

stic

s B

iolo

gy to

pic

2.3—

3-D

stru

ctur

e of

mol

ecul

es a

nd re

latin

g st

ruct

ure

to fu

nctio

n

Aim

s:

• A

im 7

: Com

pute

r sim

ulat

ions

cou

ld b

e us

ed to

mod

el V

SEP

R s

truct

ures

.


Chemistry guide 47

4.3

Cov

alen

t str

uctu

res

• E

xpla

natio

n of

the

prop

ertie

s of

gia

nt c

oval

ent c

ompo

unds

in te

rms

of th

eir

stru

ctur

es.

Gui

danc

e:

• Th

e te

rm “e

lect

ron

dom

ain”

sho

uld

be u

sed

in p

lace

of “

nega

tive

char

ge

cent

re”.

• E

lect

ron

pairs

in a

Lew

is (e

lect

ron

dot)

stru

ctur

e ca

n be

sho

wn

as d

ots,

cr

osse

s, a

das

h or

any

com

bina

tion.

• A

llotro

pes

of c

arbo

n (d

iam

ond,

gra

phite

, gra

phen

e, C

60 b

uckm

inst

erfu

llere

ne)

and

SiO

2 sho

uld

be c

over

ed.

• C

oord

inat

e co

vale

nt b

onds

sho

uld

be c

over

ed.


Chemistry guide48

Esse

ntia

l ide

a: T

he p

hysi

cal p

rope

rties

of m

olec

ular

sub

stan

ces

resu

lt fro

m d

iffer

ent t

ypes

of f

orce

s be

twee

n th

eir m

olec

ules

.

4.4

Inte

rmol

ecul

ar fo

rces

Nat

ure

of s

cien

ce:

Obt

ain

evid

ence

for s

cien

tific

theo

ries

by m

akin

g an

d te

stin

g pr

edic

tions

bas

ed o

n th

em—

Lond

on (d

ispe

rsio

n) fo

rces

and

hyd

roge

n bo

ndin

g ca

n be

use

d to

exp

lain

spe

cial

in

tera

ctio

ns. F

or e

xam

ple,

mol

ecul

ar c

oval

ent c

ompo

unds

can

exi

st in

the

liqui

d an

d so

lid s

tate

s. T

o ex

plai

n th

is, t

here

mus

t be

attra

ctiv

e fo

rces

bet

wee

n th

eir p

artic

les

whi

ch a

re s

igni

fican

tly g

reat

er th

an th

ose

that

cou

ld b

e at

tribu

ted

to g

ravi

ty. (

2.2)

Und

erst

andi

ngs:

• In

term

olec

ular

forc

es in

clud

e Lo

ndon

(dis

pers

ion)

forc

es, d

ipol

e-di

pole

forc

es

and

hydr

ogen

bon

ding

.

• Th

e re

lativ

e st

reng

ths

of th

ese

inte

ract

ions

are

Lon

don

(dis

pers

ion)

forc

es <

di

pole

-dip

ole

forc

es <

hyd

roge

n bo

nds.

App

licat

ions

and

ski

lls

• D

educ

tion

of th

e ty

pes

of in

term

olec

ular

forc

e pr

esen

t in

subs

tanc

es, b

ased

on

thei

r stru

ctur

e an

d ch

emic

al fo

rmul

a.

• E

xpla

natio

n of

the

phys

ical

pro

perti

es o

f cov

alen

t com

poun

ds (v

olat

ility

, el

ectri

cal c

ondu

ctiv

ity a

nd s

olub

ility

) in

term

s of

thei

r stru

ctur

e an

d in

term

olec

ular

forc

es.

Gui

danc

e:

• Th

e te

rm “L

ondo

n (d

ispe

rsio

n) fo

rces

” ref

ers

to in

stan

tane

ous

indu

ced

dipo

le-

indu

ced

dipo

le fo

rces

that

exi

st b

etw

een

any

atom

s or

gro

ups

of a

tom

s an

d sh

ould

be

used

for n

on-p

olar

ent

ities

. The

term

“van

der

Waa

ls” i

s an

incl

usiv

e te

rm, w

hich

incl

udes

dip

ole–

dipo

le, d

ipol

e-in

duce

d di

pole

and

Lon

don

(dis

pers

ion)

forc

es.

Theo

ry o

f kno

wle

dge:

• Th

e na

ture

of t

he h

ydro

gen

bond

is th

e to

pic

of m

uch

disc

ussi

on a

nd th

e cu

rrent

def

initi

on fr

om th

e IU

PA

C g

ives

six

crit

eria

whi

ch s

houl

d be

use

d as

ev

iden

ce fo

r the

occ

urre

nce

of h

ydro

gen

bond

ing.

How

doe

s a

spec

ializ

ed

voca

bula

ry h

elp

and

hind

er th

e gr

owth

of k

now

ledg

e?

Util

izat

ion:

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Opt

ion

A.5

—us

ing

plas

ticiz

ers

Opt

ion

A.7

—co

ntro

lling

bio

degr

adab

ility

O

ptio

n B

.3—

mel

ting

poin

ts o

f cis

-/tra

ns- f

ats

Bio

logy

topi

cs 2

.2, 2

.3, 2

.4 a

nd 2

.6—

unde

rsta

ndin

g of

inte

rmol

ecul

ar fo

rces

to w

ork

with

mol

ecul

es in

the

body

Aim

s:

• A

im 7

: Com

pute

r sim

ulat

ions

cou

ld b

e us

ed to

sho

w in

term

olec

ular

forc

es

inte

ract

ions

.


Chemistry guide 49

Esse

ntia

l ide

a: M

etal

lic b

onds

invo

lve

a la

ttice

of c

atio

ns w

ith d

eloc

aliz

ed e

lect

rons

.

4.5

Met

allic

bon

ding

Nat

ure

of s

cien

ce:

Use

theo

ries

to e

xpla

in n

atur

al p

heno

men

a—th

e pr

oper

ties

of m

etal

s ar

e di

ffere

nt fr

om c

oval

ent a

nd io

nic

subs

tanc

es a

nd th

is is

due

to th

e fo

rmat

ion

of n

on-d

irect

iona

l bo

nds

with

a “s

ea” o

f del

ocal

ized

ele

ctro

ns. (

2.2)

Und

erst

andi

ngs:

• A

met

allic

bon

d is

the

elec

trost

atic

attr

actio

n be

twee

n a

latti

ce o

f pos

itive

ions

an

d de

loca

lized

ele

ctro

ns.

• Th

e st

reng

th o

f a m

etal

lic b

ond

depe

nds

on th

e ch

arge

of t

he io

ns a

nd th

e ra

dius

of t

he m

etal

ion.

• A

lloys

usu

ally

con

tain

mor

e th

an o

ne m

etal

and

hav

e en

hanc

ed p

rope

rties

.

App

licat

ions

and

ski

lls:

• E

xpla

natio

n of

ele

ctric

al c

ondu

ctiv

ity a

nd m

alle

abili

ty in

met

als.

• E

xpla

natio

n of

tren

ds in

mel

ting

poin

ts o

f met

als.

• E

xpla

natio

n of

the

prop

ertie

s of

allo

ys in

term

s of

non

-dire

ctio

nal b

ondi

ng.

Gui

danc

e:

• Tr

ends

sho

uld

be li

mite

d to

s- a

nd p

-blo

ck e

lem

ents

.

• E

xam

ples

of v

ario

us a

lloys

sho

uld

be c

over

ed.

Inte

rnat

iona

l-min

dedn

ess:

• Th

e av

aila

bilit

y of

met

al re

sour

ces,

and

the

mea

ns to

ext

ract

them

, var

ies

grea

tly in

diff

eren

t cou

ntrie

s, a

nd is

a fa

ctor

in d

eter

min

ing

natio

nal w

ealth

. As

tech

nolo

gies

dev

elop

, the

dem

ands

for d

iffer

ent m

etal

s ch

ange

and

car

eful

st

rate

gies

are

nee

ded

to m

anag

e th

e su

pply

of t

hese

fini

te re

sour

ces.

Util

izat

ion:

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Opt

ion

A.6

—us

e of

met

als

in n

anot

echn

olog

y

Bio

logy

topi

c 2.

2—w

ater

Aim

s:

• A

im 1

: Glo

bal i

mpa

ct o

f val

ue o

f pre

ciou

s m

etal

s an

d th

eir e

xtra

ctio

n pr

oces

ses

and

loca

tions

.

• A

im 7

: Com

pute

r sim

ulat

ions

cou

ld b

e us

ed to

vie

w e

xam

ples

of m

etal

lic

bond

ing.

Topic 5: Energetics/thermochemistry

Chemistry guide50

Esse

ntia

l ide

a: T

he e

ntha

lpy

chan

ges

from

che

mic

al re

actio

ns c

an b

e ca

lcul

ated

from

thei

r effe

ct o

n th

e te

mpe

ratu

re o

f the

ir su

rroun

ding

s.

5.1

Mea

surin

g en

ergy

cha

nges

Nat

ure

of s

cien

ce:

Fund

amen

tal p

rinci

ple—

cons

erva

tion

of e

nerg

y is

a fu

ndam

enta

l prin

cipl

e of

sci

ence

. (2.

6)

Mak

ing

care

ful o

bser

vatio

ns—

mea

sura

ble

ener

gy tr

ansf

ers

betw

een

syst

ems

and

surr

ound

ings

. (3.

1)

Und

erst

andi

ngs:

• H

eat i

s a

form

of e

nerg

y.

• Te

mpe

ratu

re is

a m

easu

re o

f the

ave

rage

kin

etic

ene

rgy

of th

e pa

rticl

es.

• To

tal e

nerg

y is

con

serv

ed in

che

mic

al re

actio

ns.

• C

hem

ical

reac

tions

that

invo

lve

trans

fer o

f hea

t bet

wee

n th

e sy

stem

and

the

surro

undi

ngs

are

desc

ribed

as

endo

ther

mic

or e

xoth

erm

ic.

• Th

e en

thal

py c

hang

e (∆

H) fo

r che

mic

al re

actio

ns is

indi

cate

d in

kJ

mol

-1.

• ∆H

val

ues

are

usua

lly e

xpre

ssed

und

er s

tand

ard

cond

ition

s, g

iven

by ∆

H°,

incl

udin

g st

anda

rd s

tate

s.

App

licat

ions

and

ski

lls:

• C

alcu

latio

n of

the

heat

cha

nge

whe

n th

e te

mpe

ratu

re o

f a p

ure

subs

tanc

e is

ch

ange

d us

ing

𝑞𝑞=

𝑚𝑚𝑚𝑚∆

𝑇𝑇.

• A

cal

orim

etry

exp

erim

ent f

or a

n en

thal

py o

f rea

ctio

n sh

ould

be

cove

red

and

the

resu

lts e

valu

ated

.

Gui

danc

e:

• E

ntha

lpy

chan

ges

of c

ombu

stio

n (∆

H c° ) and

form

atio

n (∆

H f° )sho

uld

be c

over

ed.

• C

onsi

der r

eact

ions

in a

queo

us s

olut

ion

and

com

bust

ion

reac

tions

.

Inte

rnat

iona

l-min

dedn

ess:

• Th

e S

I uni

t of t

empe

ratu

re is

the

Kel

vin

(K),

but t

he C

elsi

us s

cale

(°C

), w

hich

ha

s th

e sa

me

incr

emen

tal s

calin

g, is

com

mon

ly u

sed

in m

ost c

ount

ries.

The

ex

cept

ion

is th

e U

SA

whi

ch c

ontin

ues

to u

se th

e Fa

hren

heit

scal

e (°

F) fo

r all

non-

scie

ntifi

c co

mm

unic

atio

n.

Theo

ry o

f kno

wle

dge:

• W

hat c

riter

ia d

o w

e us

e in

judg

ing

disc

repa

ncie

s be

twee

n ex

perim

enta

l and

th

eore

tical

val

ues?

Whi

ch w

ays

of k

now

ing

do w

e us

e w

hen

asse

ssin

g ex

perim

enta

l lim

itatio

ns a

nd th

eore

tical

ass

umpt

ions

?

Util

izat

ion:

• D

eter

min

ing

ener

gy c

onte

nt o

f im

porta

nt s

ubst

ance

s in

food

and

fuel

s.

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 1.

1—co

nser

vatio

n of

mas

s, c

hang

es o

f sta

te

Topi

c 1.

2—th

e m

ole

conc

ept

Aim

s:

• A

im 6

: Exp

erim

ents

cou

ld in

clud

e ca

lcul

atin

g en

thal

py c

hang

es fr

om g

iven

ex

perim

enta

l dat

a (e

nerg

y co

nten

t of f

ood,

ent

halp

y of

mel

ting

of ic

e or

the

enth

alpy

cha

nge

of s

impl

e re

actio

ns in

aqu

eous

sol

utio

n).

• A

im 7

: Use

of d

atab

ases

to a

naly

se th

e en

ergy

con

tent

of f

ood.

• A

im 7

: Use

of d

ata

logg

ers

to re

cord

tem

pera

ture

cha

nges

.

Topi

c 5:

Ene

rget

ics/

ther

moc

hem

istr

y 9

hour

s

Core


Chemistry guide 51

5.1

Mea

surin

g en

ergy

cha

nges

• S

tand

ard

stat

e re

fers

to th

e no

rmal

, mos

t pur

e st

able

sta

te o

f a s

ubst

ance

m

easu

red

at 1

00 k

Pa.

Tem

pera

ture

is n

ot a

par

t of t

he d

efin

ition

of s

tand

ard

stat

e, b

ut 2

98 K

is c

omm

only

giv

en a

s th

e te

mpe

ratu

re o

f int

eres

t.

• Th

e sp

ecifi

c he

at c

apac

ity o

f wat

er is

pro

vide

d in

the

data

boo

klet

in s

ectio

n 2.

• S

tude

nts

can

assu

me

the

dens

ity a

nd s

peci

fic h

eat c

apac

ities

of a

queo

us

solu

tions

are

equ

al to

thos

e of

wat

er, b

ut s

houl

d be

aw

are

of th

is li

mita

tion.

• H

eat l

osse

s to

the

envi

ronm

ent a

nd th

e he

at c

apac

ity o

f the

cal

orim

eter

in

expe

rimen

ts s

houl

d be

con

side

red,

but

the

use

of a

bom

b ca

lorim

eter

is n

ot

requ

ired.


Chemistry guide52

Esse

ntia

l ide

a: In

che

mic

al tr

ansf

orm

atio

ns e

nerg

y ca

n ne

ither

be

crea

ted

nor d

estro

yed

(the

first

law

of t

herm

odyn

amic

s).

5.2

Hes

s's

Law

Nat

ure

of s

cien

ce:

Hyp

othe

ses—

base

d on

the

cons

erva

tion

of e

nerg

y an

d at

omic

theo

ry, s

cien

tists

can

test

the

hypo

thes

is th

at if

the

sam

e pr

oduc

ts a

re fo

rmed

from

the

sam

e in

itial

reac

tant

s th

en th

e en

ergy

cha

nge

shou

ld b

e th

e sa

me

rega

rdle

ss o

f the

num

ber o

f ste

ps. (

2.4)

Und

erst

andi

ngs:

• Th

e en

thal

py c

hang

e fo

r a re

actio

n th

at is

car

ried

out i

n a

serie

s of

ste

ps is

eq

ual t

o th

e su

m o

f the

ent

halp

y ch

ange

s fo

r the

indi

vidu

al s

teps

.

App

licat

ions

and

ski

lls:

• A

pplic

atio

n of

Hes

s’s

Law

to c

alcu

late

ent

halp

y ch

ange

s.

• C

alcu

latio

n of

∆𝐻𝐻

reac

tions

usi

ng ∆

𝐻𝐻 𝑓𝑓° dat

a.

• D

eter

min

atio

n of

the

enth

alpy

cha

nge

of a

reac

tion

that

is th

e su

m o

f mul

tiple

re

actio

ns w

ith k

now

n en

thal

py c

hang

es.

Gui

danc

e:

• E

ntha

lpy

of fo

rmat

ion

data

can

be

foun

d in

the

data

boo

klet

in s

ectio

n 12

.

• A

n ap

plic

atio

n of

Hes

s's

Law

is ∆

𝐻𝐻 re

actio

n=

Σ(∆𝐻𝐻

𝑓𝑓° prod

ucts)

− Σ(

∆𝐻𝐻𝑓𝑓° re

acta

nts)

.

Inte

rnat

iona

l-min

dedn

ess:

• R

ecyc

ling

of m

ater

ials

is o

ften

an e

ffect

ive

mea

ns o

f red

ucin

g th

e en

viro

nmen

tal i

mpa

ct o

f pro

duct

ion,

but

var

ies

in it

s ef

ficie

ncy

in e

nerg

y te

rms

in d

iffer

ent c

ount

ries.

Theo

ry o

f kno

wle

dge:

• H

ess’

s La

w is

an

exam

ple

of th

e ap

plic

atio

n of

the

Con

serv

atio

n of

Ene

rgy.

W

hat a

re th

e ch

alle

nges

and

lim

itatio

ns o

f app

lyin

g ge

nera

l prin

cipl

es to

sp

ecifi

c in

stan

ces?

Util

izat

ion:

• H

ess’

s La

w h

as s

igni

fican

ce in

the

stud

y of

nut

ritio

n, d

rugs

, and

Gib

bs fr

ee

ener

gy w

here

dire

ct s

ynth

esis

from

con

stitu

ent e

lem

ents

is n

ot p

ossi

ble.

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Phy

sics

topi

c 2.

3—co

nser

vatio

n of

mas

s-en

ergy

Aim

s:

• A

im 4

: Dis

cuss

the

sour

ce o

f acc

epte

d va

lues

and

use

this

idea

to c

ritiq

ue

expe

rimen

ts.

• A

im 6

: Exp

erim

ents

cou

ld in

clud

e H

ess'

s La

w la

bs.

• A

im 7

: Use

of d

ata

logg

ers

to re

cord

tem

pera

ture

cha

nges

.


Chemistry guide 53

Esse

ntia

l ide

a: E

nerg

y is

abs

orbe

d w

hen

bond

s ar

e br

oken

and

is re

leas

ed w

hen

bond

s ar

e fo

rmed

.

5.3

Bon

d en

thal

pies

Nat

ure

of s

cien

ce:

Mod

els

and

theo

ries—

mea

sure

d en

ergy

cha

nges

can

be

expl

aine

d ba

sed

on th

e m

odel

of b

onds

bro

ken

and

bond

s fo

rmed

. Sin

ce th

ese

expl

anat

ions

are

bas

ed o

n a

mod

el,

agre

emen

t with

em

piric

al d

ata

depe

nds

on th

e so

phis

ticat

ion

of th

e m

odel

and

dat

a ob

tain

ed c

an b

e us

ed to

mod

ify th

eorie

s w

here

app

ropr

iate

. (2.

2)

Und

erst

andi

ngs:

• B

ond-

form

ing

rele

ases

ene

rgy

and

bond

-bre

akin

g re

quire

s en

ergy

.

• A

vera

ge b

ond

enth

alpy

is th

e en

ergy

nee

ded

to b

reak

one

mol

of a

bon

d in

a

gase

ous

mol

ecul

e av

erag

ed o

ver s

imila

r com

poun

ds.

App

licat

ions

and

ski

lls:

• C

alcu

latio

n of

the

enth

alpy

cha

nges

from

kno

wn

bond

ent

halp

y va

lues

and

co

mpa

rison

of t

hese

to e

xper

imen

tally

mea

sure

d va

lues

.

• S

ketc

hing

and

eva

luat

ion

of p

oten

tial e

nerg

y pr

ofile

s in

det

erm

inin

g w

heth

er

reac

tant

s or

pro

duct

s ar

e m

ore

stab

le a

nd if

the

reac

tion

is e

xoth

erm

ic o

r en

doth

erm

ic.

• D

iscu

ssio

n of

the

bond

stre

ngth

in o

zone

rela

tive

to o

xyge

n in

its

impo

rtanc

e to

th

e at

mos

pher

e.

Gui

danc

e:

• B

ond

enth

alpy

val

ues

are

give

n in

the

data

boo

klet

in s

ectio

n 11

.

• A

vera

ge b

ond

enth

alpi

es a

re o

nly

valid

for g

ases

and

cal

cula

tions

invo

lvin

g bo

nd e

ntha

lpie

s m

ay b

e in

accu

rate

bec

ause

they

do

not t

ake

into

acc

ount

in

term

olec

ular

forc

es.

Inte

rnat

iona

l-min

dedn

ess:

• S

trato

sphe

ric o

zone

dep

letio

n is

a p

artic

ular

con

cern

in th

e po

lar r

egio

ns o

f the

pl

anet

, alth

ough

the

pollu

tion

that

cau

ses

it co

mes

from

a v

arie

ty o

f reg

ions

and

so

urce

s. In

tern

atio

nal a

ctio

n an

d co

oper

atio

n ha

ve h

elpe

d to

am

elio

rate

the

ozon

e de

plet

ion

prob

lem

.

Util

izat

ion:

• E

nerg

y so

urce

s, s

uch

as c

ombu

stio

n of

foss

il fu

els,

requ

ire h

igh

ΔH

val

ues.

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 4.

3—co

vale

nt s

truct

ures

Aim

s:

• A

im 6

: Exp

erim

ents

cou

ld b

e en

thal

py o

f com

bust

ion

of p

ropa

ne o

r but

ane.

• A

im 7

: Dat

a lo

gger

s ca

n be

use

d to

reco

rd te

mpe

ratu

re c

hang

es.

• A

im 8

: Mor

al, e

thic

al, s

ocia

l, ec

onom

ic a

nd e

nviro

nmen

tal c

onse

quen

ces

of

ozon

e de

plet

ion

and

its c

ause

s.

Topic 6: Chemical kinetics

Chemistry guide54

Core Topi

c 6:

Che

mic

al k

inet

ics

7 ho

urs

Esse

ntia

l ide

a: T

he g

reat

er th

e pr

obab

ility

that

mol

ecul

es w

ill c

ollid

e w

ith s

uffic

ient

ene

rgy

and

prop

er o

rient

atio

n, th

e hi

gher

the

rate

of r

eact

ion.

6.1

Col

lisio

n th

eory

and

rate

s of

reac

tion

Nat

ure

of s

cien

ce:

The

prin

cipl

e of

Occ

am’s

razo

r is

used

as

a gu

ide

to d

evel

opin

g a

theo

ry—

alth

ough

we

cann

ot d

irect

ly s

ee re

actio

ns ta

king

pla

ce a

t the

mol

ecul

ar le

vel,

we

can

theo

rize

base

d on

the

curre

nt a

tom

ic m

odel

s. C

ollis

ion

theo

ry is

a g

ood

exam

ple

of th

is p

rinci

ple.

(2.7

)

Und

erst

andi

ngs:

• S

peci

es re

act a

s a

resu

lt of

col

lisio

ns o

f suf

ficie

nt e

nerg

y an

d pr

oper

or

ient

atio

n.

• Th

e ra

te o

f rea

ctio

n is

exp

ress

ed a

s th

e ch

ange

in c

once

ntra

tion

of a

par

ticul

ar

reac

tant

/pro

duct

per

uni

t tim

e.

• C

once

ntra

tion

chan

ges

in a

reac

tion

can

be fo

llow

ed in

dire

ctly

by

mon

itorin

g ch

ange

s in

mas

s, v

olum

e an

d co

lour

.

• A

ctiv

atio

n en

ergy

(Ea)

is th

e m

inim

um e

nerg

y th

at c

ollid

ing

mol

ecul

es n

eed

in

orde

r to

have

suc

cess

ful c

ollis

ions

lead

ing

to a

reac

tion.

• B

y de

crea

sing

Ea,

a ca

taly

st in

crea

ses

the

rate

of a

che

mic

al re

actio

n, w

ithou

t its

elf b

eing

per

man

ently

che

mic

ally

cha

nged

.

App

licat

ions

and

ski

lls:

• D

escr

iptio

n of

the

kine

tic th

eory

in te

rms

of th

e m

ovem

ent o

f par

ticle

s w

hose

av

erag

e ki

netic

ene

rgy

is p

ropo

rtion

al to

tem

pera

ture

in K

elvi

n.

• A

naly

sis

of g

raph

ical

and

num

eric

al d

ata

from

rate

exp

erim

ents

.

Inte

rnat

iona

l-min

dedn

ess:

• D

eple

tion

of s

trato

sphe

ric o

zone

has

bee

n ca

used

larg

ely

by th

e ca

taly

tic

actio

n of

CFC

s an

d is

a p

artic

ular

con

cern

in th

e po

lar r

egio

ns. T

hese

ch

emic

als

are

rele

ased

from

a v

arie

ty o

f reg

ions

and

sou

rces

, so

inte

rnat

iona

l ac

tion

and

coop

erat

ion

have

bee

n ne

eded

to a

mel

iora

te th

e oz

one

depl

etio

n pr

oble

m.

Theo

ry o

f kno

wle

dge:

• Th

e K

elvi

n sc

ale

of te

mpe

ratu

re g

ives

a n

atur

al m

easu

re o

f the

kin

etic

ene

rgy

of g

as w

here

as th

e ar

tific

ial C

elsi

us s

cale

is b

ased

on

the

prop

ertie

s of

wat

er.

Are

phy

sica

l pro

perti

es s

uch

as te

mpe

ratu

re in

vent

ed o

r dis

cove

red?

Util

izat

ion:

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 5.

3—w

hat m

ight

be

mea

nt b

y th

erm

odyn

amic

ally

sta

ble

vs k

inet

ical

ly s

tabl

e?

Topi

c 13

.1—

firew

orks

and

ions

O

ptio

n A

.3—

ever

yday

use

s of

cat

alys

ts

Opt

ion

B.2

—en

zym

es

Bio

logy

topi

c 8.

1—m

etab

olis

m


Chemistry guide 55

6.1

Col

lisio

n th

eory

and

rate

s of

reac

tion

• E

xpla

natio

n of

the

effe

cts

of te

mpe

ratu

re, p

ress

ure/

conc

entra

tion

and

parti

cle

size

on

rate

of r

eact

ion.

• C

onst

ruct

ion

of M

axw

ell–

Bol

tzm

ann

ener

gy d

istri

butio

n cu

rves

to a

ccou

nt fo

r th

e pr

obab

ility

of s

ucce

ssfu

l col

lisio

ns a

nd fa

ctor

s af

fect

ing

thes

e, in

clud

ing

the

effe

ct o

f a c

atal

yst.

• In

vest

igat

ion

of ra

tes

of re

actio

n ex

perim

enta

lly a

nd e

valu

atio

n of

the

resu

lts.

• S

ketc

hing

and

exp

lana

tion

of e

nerg

y pr

ofile

s w

ith a

nd w

ithou

t cat

alys

ts.

Gui

danc

e:

• C

alcu

latio

n of

reac

tion

rate

s fro

m ta

ngen

ts o

f gra

phs

of c

once

ntra

tion,

vol

ume

or m

ass

agai

nst t

ime

shou

ld b

e co

vere

d.

• S

tude

nts

shou

ld b

e fa

mili

ar w

ith th

e in

terp

reta

tion

of g

raph

s of

cha

nges

in

conc

entra

tion,

vol

ume

or m

ass

agai

nst t

ime.

Aim

s:

• A

ims

1 an

d 8:

Wha

t are

som

e of

the

cont

rove

rsie

s ov

er ra

te o

f clim

ate

chan

ge?

Why

do

thes

e ex

ist?

• A

im 6

: Inv

estig

ate

the

rate

of a

reac

tion

with

and

with

out a

cat

alys

t.

• A

im 6

: Exp

erim

ents

cou

ld in

clud

e in

vest

igat

ing

rate

s by

cha

ngin

g co

ncen

tratio

n of

a re

acta

nt o

r tem

pera

ture

.

• A

im 7

: Use

sim

ulat

ions

to s

how

how

mol

ecul

ar c

ollis

ions

are

affe

cted

by

chan

ge o

f mac

rosc

opic

pro

perti

es s

uch

as te

mpe

ratu

re, p

ress

ure

and

conc

entra

tion.

• A

im 8

: The

role

that

cat

alys

ts p

lay

in th

e fie

ld o

f gre

en c

hem

istry

.

Topic 7: Equilibrium

Chemistry guide56

Core Topi

c 7:

Equ

ilibr

ium

4.

5 ho

urs

Esse

ntia

l ide

a: M

any

reac

tions

are

reve

rsib

le. T

hese

reac

tions

will

reac

h a

stat

e of

equ

ilibr

ium

whe

n th

e ra

tes

of th

e fo

rwar

d an

d re

vers

e re

actio

n ar

e eq

ual.

The

posi

tion

of

equi

libriu

m c

an b

e co

ntro

lled

by c

hang

ing

the

cond

ition

s.

7.1

Equi

libriu

m

Nat

ure

of s

cien

ce:

Obt

aini

ng e

vide

nce

for s

cien

tific

theo

ries—

isot

opic

labe

lling

and

its

use

in d

efin

ing

equi

libriu

m. (

1.8)

Com

mon

lang

uage

acr

oss

diffe

rent

dis

cipl

ines

—th

e te

rm d

ynam

ic e

quili

briu

m is

use

d in

oth

er c

onte

xts,

but

not

nec

essa

rily

with

the

chem

istry

def

initi

on in

min

d. (5

.5)

Und

erst

andi

ngs:

• A

sta

te o

f equ

ilibr

ium

is re

ache

d in

a c

lose

d sy

stem

whe

n th

e ra

tes

of th

e fo

rwar

d an

d re

vers

e re

actio

ns a

re e

qual

.

• Th

e eq

uilib

rium

law

des

crib

es h

ow th

e eq

uilib

rium

con

stan

t (K

c) ca

n be

de

term

ined

for a

par

ticul

ar c

hem

ical

reac

tion.

• Th

e m

agni

tude

of t

he e

quili

briu

m c

onst

ant i

ndic

ates

the

exte

nt o

f a re

actio

n at

eq

uilib

rium

and

is te

mpe

ratu

re d

epen

dent

.

• Th

e re

actio

n qu

otie

nt (Q

) mea

sure

s th

e re

lativ

e am

ount

of p

rodu

cts

and

reac

tant

s pr

esen

t dur

ing

a re

actio

n at

a p

artic

ular

poi

nt in

tim

e. Q

is th

e eq

uilib

rium

exp

ress

ion

with

non

-equ

ilibr

ium

con

cent

ratio

ns. T

he p

ositi

on o

f the

eq

uilib

rium

cha

nges

with

cha

nges

in c

once

ntra

tion,

pre

ssur

e, a

nd te

mpe

ratu

re.

• A

cat

alys

t has

no

effe

ct o

n th

e po

sitio

n of

equ

ilibr

ium

or t

he e

quili

briu

m

cons

tant

.

App

licat

ions

and

ski

lls:

• Th

e ch

arac

teris

tics

of c

hem

ical

and

phy

sica

l sys

tem

s in

a s

tate

of e

quili

briu

m.

• D

educ

tion

of th

e eq

uilib

rium

con

stan

t exp

ress

ion

(Kc)

from

an

equa

tion

for a

ho

mog

eneo

us re

actio

n.

• D

eter

min

atio

n of

the

rela

tions

hip

betw

een

diffe

rent

equ

ilibr

ium

con

stan

ts (K

c) fo

r the

sam

e re

actio

n (a

t the

sam

e te

mpe

ratu

re) w

hen

repr

esen

ted

by

equa

tions

writ

ten

in d

iffer

ent w

ays.

Inte

rnat

iona

l-min

dedn

ess:

• Th

e H

aber

pro

cess

has

bee

n de

scrib

ed a

s th

e m

ost i

mpo

rtant

che

mic

al

reac

tion

on E

arth

as

it ha

s re

volu

tioni

zed

glob

al fo

od p

rodu

ctio

n. H

owev

er, i

t al

so h

ad a

larg

e im

pact

on

wea

ponr

y in

bot

h w

orld

war

s.

Theo

ry o

f kno

wle

dge:

• S

cien

tists

inve

stig

ate

the

wor

ld a

t diff

eren

t sca

les;

the

mac

rosc

opic

and

m

icro

scop

ic. W

hich

way

s of

kno

win

g al

low

us

to m

ove

from

the

mac

rosc

opic

to

the

mic

rosc

opic

?

• C

hem

istry

use

s a

spec

ializ

ed v

ocab

ular

y: a

clo

sed

syst

em is

one

in w

hich

no

mat

ter i

s ex

chan

ged

with

the

surro

undi

ngs.

Doe

s ou

r voc

abul

ary

sim

ply

com

mun

icat

e ou

r kno

wle

dge;

or d

oes

it sh

ape

wha

t we

can

know

?

• Th

e ca

reer

of F

ritz

Hab

er c

oinc

ided

with

the

polit

ical

uph

eava

ls o

f tw

o w

orld

w

ars.

He

supe

rvis

ed th

e re

leas

e of

chl

orin

e on

the

battl

efie

ld in

Wor

ld W

ar I

and

wor

ked

on th

e pr

oduc

tion

of e

xplo

sive

s. H

ow d

oes

the

soci

al c

onte

xt o

f sc

ient

ific

wor

k af

fect

the

met

hods

and

find

ings

of s

cien

ce?

Sho

uld

scie

ntis

ts b

e he

ld m

oral

ly re

spon

sibl

e fo

r the

app

licat

ions

of t

heir

disc

over

ies?

Util

izat

ion:

• S

quar

e br

acke

ts a

re u

sed

in c

hem

istry

in a

rang

e of

con

text

s: e

g co

ncen

tratio

ns (t

opic

1.3

), Le

wis

(ele

ctro

n do

t) st

ruct

ures

(top

ic 4

.3) a

nd

com

plex

es (t

opic

14.

1).


Chemistry guide 57

7.1

Equi

libriu

m

• A

pplic

atio

n of

Le

Châ

telie

r’s p

rinci

ple

to p

redi

ct th

e qu

alita

tive

effe

cts

of

chan

ges

of te

mpe

ratu

re, p

ress

ure

and

conc

entra

tion

on th

e po

sitio

n of

eq

uilib

rium

and

on

the

valu

e of

the

equi

libriu

m c

onst

ant.

Gu i

danc

e:

• P

hysi

cal a

nd c

hem

ical

sys

tem

s sh

ould

be

cove

red.

• R

elat

ions

hip

betw

een

Kc v

alue

s fo

r rea

ctio

ns th

at a

re m

ultip

les

or in

vers

es o

f on

e an

othe

r sho

uld

be c

over

ed.

• S

peci

fic d

etai

ls o

f any

indu

stria

l pro

cess

are

not

requ

ired.

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 8.

4—th

e be

havi

our o

f wea

k ac

ids

and

base

s

Aim

s:

• A

im 6

: Le

Châ

telie

r’s p

rinci

ple

can

be in

vest

igat

ed q

ualit

ativ

ely

by lo

okin

g at

pr

essu

re, c

once

ntra

tion

and

tem

pera

ture

cha

nges

on

diffe

rent

equ

ilibr

ium

sy

stem

s.

• A

im 7

: Ani

mat

ions

and

sim

ulat

ions

can

be

used

to il

lust

rate

the

conc

ept o

f dy

nam

ic e

quili

briu

m.

• A

im 8

: Rai

se a

war

enes

s of

the

mor

al, e

thic

al, a

nd e

cono

mic

impl

icat

ions

of

usin

g sc

ienc

e an

d te

chno

logy

. A c

ase

stud

y of

Frit

z H

aber

can

be

used

to

deba

te th

e ro

le o

f sci

entis

ts in

soc

iety

.

Topic 8: Acids and bases

Chemistry guide58

Esse

ntia

l ide

a: M

any

reac

tions

invo

lve

the

trans

fer o

f a p

roto

n fro

m a

n ac

id to

a b

ase.

8.1

Theo

ries

of a

cids

and

bas

es

Nat

ure

of s

cien

ce:

Fals

ifica

tion

of th

eorie

s—H

CN

alte

ring

the

theo

ry th

at o

xyge

n w

as th

e el

emen

t whi

ch g

ave

a co

mpo

und

its a

cidi

c pr

oper

ties

allo

wed

for o

ther

aci

d–ba

se th

eorie

s to

dev

elop

. (2

.5)

Theo

ries

bein

g su

pers

eded

—on

e ea

rly th

eory

of a

cidi

ty d

eriv

ed fr

om th

e se

nsat

ion

of a

sou

r tas

te, b

ut th

is h

ad b

een

prov

en fa

lse.

(1.9

)

Pub

lic u

nder

stan

ding

of s

cien

ce—

outs

ide

of th

e ar

ena

of c

hem

istry

, dec

isio

ns a

re s

omet

imes

refe

rred

to a

s "a

cid

test

" or "

litm

us te

st".

(5.5

)

Und

erst

andi

ngs:

• A

Brø

nste

d–Lo

wry

aci

d is

a p

roto

n/H

+ don

or a

nd a

Brø

nste

d–Lo

wry

bas

e is

a

prot

on/H

+ acc

epto

r.

• A

mph

ipro

tic s

peci

es c

an a

ct a

s bo

th B

røns

ted–

Low

ry a

cids

and

bas

es.

• A

pai

r of s

peci

es d

iffer

ing

by a

sin

gle

prot

on is

cal

led

a co

njug

ate

acid

-bas

e pa

ir.

App

licat

ions

and

ski

lls:

• D

educ

tion

of th

e B

røns

ted–

Low

ry a

cid

and

base

in a

che

mic

al re

actio

n.

• D

educ

tion

of th

e co

njug

ate

acid

or c

onju

gate

bas

e in

a c

hem

ical

reac

tion.

Gui

danc

e:

• Le

wis

theo

ry is

not

requ

ired

here

.

• Th

e lo

catio

n of

the

prot

on tr

ansf

erre

d sh

ould

be

clea

rly in

dica

ted.

For

exa

mpl

e,

CH

3CO

OH

/CH

3CO

O– r

athe

r tha

n C

2H4O

2/C2H

3O2– .

• S

tude

nts

shou

ld k

now

the

repr

esen

tatio

n of

a p

roto

n in

aqu

eous

sol

utio

n as

bo

th H

+ (aq

) and

H3O

+ (aq

).

• Th

e di

ffere

nce

betw

een

the

term

s am

phot

eric

and

am

phip

rotic

sho

uld

be

cove

red.

Inte

rnat

iona

l-min

dedn

ess:

• A

cidu

s m

eans

sou

r in

Latin

, whi

le a

lkal

i is

deriv

ed fr

om th

e A

rabi

c w

ord

for

calc

ined

ash

es. O

xyge

ne m

eans

aci

d-fo

rmin

g in

Gre

ek, a

nd re

flect

s th

e m

ista

ken

belie

f tha

t the

ele

men

t oxy

gen

was

resp

onsi

ble

for a

com

poun

d’s

acid

ic p

rope

rties

. Aci

d–ba

se th

eory

has

bee

n de

velo

ped

by s

cien

tists

from

ar

ound

the

wor

ld, a

nd it

s vo

cabu

lary

has

bee

n in

fluen

ced

by th

eir l

angu

ages

.

Theo

ry o

f kno

wle

dge:

• A

cid

and

base

beh

avio

ur c

an b

e ex

plai

ned

usin

g di

ffere

nt th

eorie

s. H

ow a

re th

e ex

plan

atio

ns in

che

mis

try d

iffer

ent f

rom

exp

lana

tions

in o

ther

sub

ject

s su

ch a

s hi

stor

y?

Util

izat

ion:

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 3.

2—th

e ac

id/b

ase

char

acte

r of o

xide

s To

pic

8.5—

non-

met

al o

xide

s ar

e re

spon

sibl

e fo

r aci

d pr

ecip

itatio

n

Opt

ion

B.2

—am

ino

acid

s ac

ting

as a

mph

ipro

tic s

peci

es

Opt

ion

D.4

—an

taci

ds a

re b

ases

whi

ch n

eutra

lize

exce

ss h

ydro

chlo

ric a

cid

in th

e st

omac

h

Aim

s:

• A

im 9

: Eac

h th

eory

has

its

stre

ngth

s an

d lim

itatio

ns. L

avoi

sier

has

bee

n ca

lled

the

fath

er o

f mod

ern

chem

istry

but

he

was

mis

take

n ab

out o

xyge

n in

this

co

ntex

t.

Topi

c 8:

Aci

ds a

nd b

ases

6.

5 ho

urs

Core


Chemistry guide 59

Esse

ntia

l ide

a: T

he c

hara

cter

izat

ion

of a

n ac

id d

epen

ds o

n em

piric

al e

vide

nce

such

as

the

prod

uctio

n of

gas

es in

reac

tions

with

met

als,

the

colo

ur c

hang

es o

f ind

icat

ors

or

the

rele

ase

of h

eat i

n re

actio

ns w

ith m

etal

oxi

des

and

hydr

oxid

es.

8.2

Prop

ertie

s of

aci

ds a

nd b

ases

Nat

ure

of s

cien

ce:

Obt

aini

ng e

vide

nce

for t

heor

ies—

obse

rvab

le p

rope

rties

of a

cids

and

bas

es h

ave

led

to th

e m

odifi

catio

n of

aci

d–ba

se th

eorie

s. (1

.9)

Und

erst

andi

ngs:

• M

ost a

cids

hav

e ob

serv

able

cha

ract

eris

tic c

hem

ical

reac

tions

with

reac

tive

met

als,

met

al o

xide

s, m

etal

hyd

roxi

des,

hyd

roge

n ca

rbon

ates

and

car

bona

tes.

• S

alt a

nd w

ater

are

pro

duce

d in

exo

ther

mic

neu

traliz

atio

n re

actio

ns.

App

licat

ions

and

ski

lls:

• B

alan

cing

che

mic

al e

quat

ions

for t

he re

actio

n of

aci

ds.

• Id

entif

icat

ion

of th

e ac

id a

nd b

ase

need

ed to

mak

e di

ffere

nt s

alts

.

• C

andi

date

s sh

ould

hav

e ex

perie

nce

of a

cid-

base

titra

tions

with

diff

eren

t in

dica

tors

.

Gui

danc

e:

• B

ases

whi

ch a

re n

ot h

ydro

xide

s, s

uch

as a

mm

onia

, sol

uble

car

bona

tes

and

hydr

ogen

car

bona

tes

shou

ld b

e co

vere

d.

• Th

e co

lour

cha

nges

of d

iffer

ent i

ndic

ator

s ar

e gi

ven

in th

e da

ta b

ookl

et in

se

ctio

n 22

.

Util

izat

ion:

• A

num

ber o

f aci

ds a

nd b

ases

are

use

d in

our

eve

ryda

y lif

e fro

m ru

st re

mov

ers

to o

ven

clea

ners

, fro

m fo

ods

to to

othp

aste

s, fr

om tr

eatm

ents

for b

ee s

tings

to

treat

men

t of w

asp

stin

gs.

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 1.

3—ac

id–b

ase

titra

tions

To

pic

3.2—

the

acid

/bas

e ch

arac

ter o

f oxi

des

To

pic

5.1—

enth

alpy

cha

nge

of n

eutra

lizat

ion

reac

tions

Aim

s:

• A

im 6

: The

evi

denc

e fo

r the

se p

rope

rties

cou

ld b

e ba

sed

on a

stu

dent

’s

expe

rimen

tal e

xper

ienc

es.


Chemistry guide60

Esse

ntia

l ide

a: T

he p

H s

cale

is a

n ar

tific

ial s

cale

use

d to

dis

tingu

ish

betw

een

acid

, neu

tral a

nd b

asic

/alk

alin

e so

lutio

ns.

8.3

The

pH s

cale

Nat

ure

of s

cien

ce:

Occ

am’s

razo

r—th

e pH

sca

le is

an

atte

mpt

to s

cale

the

rela

tive

acid

ity o

ver a

wid

e ra

nge

of H

+ con

cent

ratio

ns in

to a

ver

y si

mpl

e nu

mbe

r. (2

.7)

Und

erst

andi

ngs:

• pH

=−

log[

H+ ( aq)

] and

[H+

]=10

−pH

.

• A

cha

nge

of o

ne p

H u

nit r

epre

sent

s a

10-fo

ld c

hang

e in

the

hydr

ogen

ion

conc

entra

tion

[H+

].

• pH

val

ues

dist

ingu

ish

betw

een

acid

ic, n

eutra

l and

alk

alin

e so

lutio

ns.

• Th

e io

nic

prod

uct c

onst

ant,

𝐾𝐾 𝑤𝑤=

[ H+

][ OH−

] = 1

0−14 a

t 298

K.

App

licat

ions

and

ski

lls:

• S

olvi

ng p

robl

ems

invo

lvin

g pH

,[ H+

] and

[OH− ].

• S

tude

nts

shou

ld b

e fa

mili

ar w

ith th

e us

e of

a p

H m

eter

and

uni

vers

al in

dica

tor.

Gui

danc

e:

• S

tude

nts

will

not

be

asse

ssed

on

pOH

valu

es.

• S

tude

nts

shou

ld b

e co

ncer

ned

only

with

stro

ng a

cids

and

bas

es in

this

sub

-to

pic.

• K

now

ing

the

tem

pera

ture

dep

ende

nce

of 𝐾𝐾

𝑤𝑤 is

not

requ

ired.

• E

quat

ions

invo

lvin

g H

3O+ i

nste

ad o

f H+ m

ay b

e ap

plie

d.

Theo

ry o

f kno

wle

dge:

• C

hem

istry

mak

es u

se o

f the

uni

vers

al la

ngua

ge o

f mat

hem

atic

s as

a m

eans

of

com

mun

icat

ion.

Why

is it

impo

rtant

to h

ave

just

one

“sci

entif

ic” l

angu

age?

Util

izat

ion:

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Mat

hem

atic

s S

L (to

pic

1.2)

and

Mat

hem

atic

s H

L (to

pic

1.2)

—st

udy

of lo

gs

Aim

s:

• A

im 3

: Stu

dent

s sh

ould

be

able

to u

se a

nd a

pply

the

pH c

once

pt in

a ra

nge

of

expe

rimen

tal a

nd th

eore

tical

con

text

s.

• A

im 6

: An

acid

–bas

e tit

ratio

n co

uld

be m

onito

red

with

an

indi

cato

r or a

pH

pr

obe.


Chemistry guide 61

Esse

ntia

l ide

a: T

he p

H d

epen

ds o

n th

e co

ncen

tratio

n of

the

solu

tion.

The

stre

ngth

of a

cids

or b

ases

dep

ends

on

the

exte

nt to

whi

ch th

ey d

isso

ciat

e in

aqu

eous

sol

utio

n.

8.4

Stro

ng a

nd w

eak

acid

s an

d ba

ses

Nat

ure

of s

cien

ce:

Impr

oved

inst

rum

enta

tion—

the

use

of a

dvan

ced

anal

ytic

al te

chni

ques

has

allo

wed

the

rela

tive

stre

ngth

of d

iffer

ent a

cids

and

bas

es to

be

quan

tifie

d. (1

.8)

Look

ing

for t

rend

s an

d di

scre

panc

ies—

patte

rns

and

anom

alie

s in

rela

tive

stre

ngth

s of

aci

ds a

nd b

ases

can

be

expl

aine

d at

the

mol

ecul

ar le

vel.

(3.1

)

The

outc

omes

of e

xper

imen

ts o

r mod

els

may

be

used

as

furth

er e

vide

nce

for a

cla

im—

data

for a

par

ticul

ar ty

pe o

f rea

ctio

n su

ppor

ts th

e id

ea th

at w

eak

acid

s ex

ist i

n eq

uilib

rium

. (1.

9)

Und

erst

andi

ngs:

• S

trong

and

wea

k ac

ids

and

base

s di

ffer i

n th

e ex

tent

of i

oniz

atio

n.

• S

trong

aci

ds a

nd b

ases

of e

qual

con

cent

ratio

ns h

ave

high

er c

ondu

ctiv

ities

than

w

eak

acid

s an

d ba

ses.

• A

stro

ng a

cid

is a

goo

d pr

oton

don

or a

nd h

as a

wea

k co

njug

ate

base

.

• A

stro

ng b

ase

is a

goo

d pr

oton

acc

epto

r and

has

a w

eak

conj

ugat

e ac

id.

App

licat

ions

and

ski

lls:

• D

istin

ctio

n be

twee

n st

rong

and

wea

k ac

ids

in te

rms

of th

e ra

tes

of th

eir

reac

tions

with

met

als,

met

al o

xide

s, m

etal

hyd

roxi

des,

met

al h

ydro

gen

carb

onat

es a

nd m

etal

car

bona

tes.

Stro

ng a

nd w

eak

acid

s an

d ba

ses

also

diff

er

in th

eir e

lect

rical

con

duct

iviti

es fo

r sol

utio

ns o

f equ

al c

once

ntra

tions

.

Gui

danc

e:

• Th

e te

rms

ioni

zatio

n an

d di

ssoc

iatio

n ca

n be

use

d in

terc

hang

eabl

y.

• S

ee s

ectio

n 21

in th

e da

ta b

ookl

et fo

r a li

st o

f wea

k ac

ids

and

base

s.

Theo

ry o

f kno

wle

dge:

• Th

e st

reng

th o

f an

acid

can

be

dete

rmin

ed b

y th

e us

e of

pH

and

con

duct

ivity

pr

obes

. In

wha

t way

s do

tech

nolo

gies

, whi

ch e

xten

d ou

r sen

ses,

cha

nge

or

rein

forc

e ou

r vie

w o

f the

wor

ld?

Util

izat

ion:

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 1.

3—so

lutio

n ch

emis

try

Topi

c 7.

1—w

eak

acid

s an

d ba

ses

invo

lve

reve

rsib

le re

actio

ns

Aim

s:

• A

im 6

: Stu

dent

s sh

ould

hav

e ex

perim

enta

l exp

erie

nce

of w

orki

ng q

ualit

ativ

ely

with

bot

h st

rong

and

wea

k ac

ids

and

base

s. E

xam

ples

to in

clud

e: H

2SO

4 (a

q),

HC

l (aq

), H

NO

3 (a

q), N

aOH

(aq)

, NH

3 (a

q).

• A

im 7

: Stu

dent

s co

uld

use

data

logg

ers

to in

vest

igat

e th

e st

reng

th o

f aci

d an

d ba

ses.


Chemistry guide62

Esse

ntia

l ide

a: In

crea

sed

indu

stria

lizat

ion

has

led

to g

reat

er p

rodu

ctio

n of

nitr

ogen

and

sul

fur o

xide

s le

adin

g to

aci

d ra

in, w

hich

is d

amag

ing

our e

nviro

nmen

t. Th

ese

prob

lem

s ca

n be

redu

ced

thro

ugh

colla

bora

tion

with

nat

iona

l and

inte

rgov

ernm

enta

l org

aniz

atio

ns.

8.5

Acid

dep

ositi

on

Nat

ure

of s

cien

ce:

Ris

ks a

nd p

robl

ems—

oxid

es o

f met

als

and

non-

met

als

can

be c

hara

cter

ized

by

thei

r aci

d–ba

se p

rope

rties

. Aci

d de

posi

tion

is a

topi

c th

at c

an b

e di

scus

sed

from

diff

eren

t pe

rspe

ctiv

es. C

hem

istry

allo

ws

us to

und

erst

and

and

to re

duce

the

envi

ronm

enta

l im

pact

of h

uman

act

iviti

es. (

4.8)

Und

erst

andi

ngs:

• R

ain

is n

atur

ally

aci

dic

beca

use

of d

isso

lved

CO

2 and

has

a p

H o

f 5.6

. Aci

d de

posi

tion

has

a pH

bel

ow 5

.6.

• A

cid

depo

sitio

n is

form

ed w

hen

nitro

gen

or s

ulfu

r oxi

des

diss

olve

in w

ater

to

form

HN

O3,

HN

O2,

H2S

O4 a

nd H

2SO

3.

• S

ourc

es o

f the

oxi

des

of s

ulfu

r and

nitr

ogen

and

the

effe

cts

of a

cid

depo

sitio

n sh

ould

be

cove

red.

App

licat

ions

and

ski

lls:

• B

alan

cing

the

equa

tions

that

des

crib

e th

e co

mbu

stio

n of

sul

fur a

nd n

itrog

en to

th

eir o

xide

s an

d th

e su

bseq

uent

form

atio

n of

H2S

O3,

H2S

O4,

HN

O2 a

nd H

NO

3.

• D

istin

ctio

n be

twee

n th

e pr

e-co

mbu

stio

n an

d po

st-c

ombu

stio

n m

etho

ds o

f re

duci

ng s

ulfu

r oxi

des

emis

sion

s.

• D

educ

tion

of a

cid

depo

sitio

n eq

uatio

ns fo

r aci

d de

posi

tion

with

reac

tive

met

als

and

carb

onat

es.

Inte

rnat

iona

l-min

dedn

ess:

• Th

e po

llute

r cou

ntry

and

pol

lute

d co

untry

are

ofte

n no

t the

sam

e. A

cid

depo

sitio

n is

a s

econ

dary

pol

luta

nt th

at a

ffect

s re

gion

s fa

r fro

m th

e pr

imar

y so

urce

. Sol

ving

this

pro

blem

requ

ires

inte

rnat

iona

l coo

pera

tion.

Theo

ry o

f kno

wle

dge:

• A

ll ra

in is

aci

dic

but n

ot a

ll ra

in is

“aci

d ra

in”.

Sci

entif

ic te

rms

have

a p

reci

se

defin

ition

. Doe

s sc

ient

ific

voca

bula

ry s

impl

y co

mm

unic

ate

our k

now

ledg

e in

a

neut

ral w

ay o

r can

it h

ave

valu

e-la

den

term

inol

ogy?

Util

izat

ion:

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 3.

2—th

e ac

id/b

ase

char

acte

r of t

he o

xide

s

Opt

ion

B.2

—pH

cha

nge

and

enzy

me

activ

ity

Opt

ion

C.2

—su

lfur d

ioxi

de is

pro

duce

d by

the

com

bust

ion

of fo

ssil

fuel

s w

ith h

igh

leve

ls o

f sul

fur i

mpu

ritie

s

Env

ironm

enta

l sys

tem

s an

d so

ciet

ies

topi

c 5.

8—ac

id d

epos

ition

G

eogr

aphy

Opt

ion

G: U

rban

Env

ironm

ents

—ur

ban

stre

ss a

nd th

e su

stai

nabl

e ci

ty;

HL—

Glo

bal i

nter

actio

ns—

envi

ronm

enta

l cha

nge

Aim

s:

• A

im 6

: The

effe

cts

of a

cid

rain

on

diffe

rent

con

stru

ctio

n m

ater

ials

cou

ld b

e qu

antit

ativ

ely

inve

stig

ated

.

• A

im 8

: A d

iscu

ssio

n of

the

impa

ct o

f aci

d ra

in in

diff

eren

t cou

ntrie

s w

ill h

elp

rais

e aw

aren

ess

of th

e en

viro

nmen

tal i

mpa

ct o

f thi

s se

cond

ary

pollu

tant

and

th

e po

litic

al im

plic

atio

ns.

• A

im 8

: Oth

er m

eans

of r

educ

ing

oxid

e pr

oduc

tion—

bus

use,

car

poo

ling,

etc

. co

uld

be d

iscu

ssed

.

Topic 9: Redox processes


Topi

c 9:

Red

ox p

roce

sses

8

hour

s

Core

Esse

ntia

l ide

a: R

edox

(red

uctio

n–ox

idat

ion)

reac

tions

pla

y a

key

role

in m

any

chem

ical

and

bio

chem

ical

pro

cess

es.

9.1

Oxi

datio

n an

d re

duct

ion

Nat

ure

of s

cien

ce:

How

evi

denc

e is

use

d—ch

ange

s in

the

defin

ition

of o

xida

tion

and

redu

ctio

n fro

m o

ne in

volv

ing

spec

ific

elem

ents

(oxy

gen

and

hydr

ogen

), to

one

invo

lvin

g el

ectro

n tra

nsfe

r, to

one

invo

king

oxi

datio

n nu

mbe

rs is

a g

ood

exam

ple

of th

e w

ay th

at s

cien

tists

bro

aden

sim

ilarit

ies

to g

ener

al p

rinci

ples

. (1.

9)

Und

erst

andi

ngs:

• O

xida

tion

and

redu

ctio

n ca

n be

con

side

red

in te

rms

of o

xyge

n ga

in/h

ydro

gen

loss

, ele

ctro

n tra

nsfe

r or c

hang

e in

oxi

datio

n nu

mbe

r.

• A

n ox

idiz

ing

agen

t is

redu

ced

and

a re

duci

ng a

gent

is o

xidi

zed.

• V

aria

ble

oxid

atio

n nu

mbe

rs e

xist

for t

rans

ition

met

als

and

for m

ost m

ain-

grou

p no

n-m

etal

s.

• Th

e ac

tivity

ser

ies

rank

s m

etal

s ac

cord

ing

to th

e ea

se w

ith w

hich

they

und

ergo

ox

idat

ion.

• Th

e W

inkl

er M

etho

d ca

n be

use

d to

mea

sure

bio

chem

ical

oxy

gen

dem

and

(BO

D),

used

as

a m

easu

re o

f the

deg

ree

of p

ollu

tion

in a

wat

er s

ampl

e.

App

licat

ions

and

ski

lls:

• D

educ

tion

of th

e ox

idat

ion

stat

es o

f an

atom

in a

n io

n or

a c

ompo

und.

• D

educ

tion

of th

e na

me

of a

tran

sitio

n m

etal

com

poun

d fro

m a

giv

en fo

rmul

a,

appl

ying

oxi

datio

n nu

mbe

rs re

pres

ente

d by

Rom

an n

umer

als.

• Id

entif

icat

ion

of th

e sp

ecie

s ox

idiz

ed a

nd re

duce

d an

d th

e ox

idiz

ing

and

redu

cing

age

nts,

in re

dox

reac

tions

.

• D

educ

tion

of re

dox

reac

tions

usi

ng h

alf-e

quat

ions

in a

cidi

c or

neu

tral s

olut

ions

.

• D

educ

tion

of th

e fe

asib

ility

of a

redo

x re

actio

n fro

m th

e ac

tivity

ser

ies

or

reac

tion

data

.

Inte

rnat

iona

l-min

dedn

ess:

• A

cces

s to

a s

uppl

y of

cle

an d

rinki

ng w

ater

has

bee

n re

cogn

ized

by

the

Uni

ted

Nat

ions

as

a fu

ndam

enta

l hum

an ri

ght,

yet i

t is

estim

ated

that

ove

r one

bill

ion

peop

le la

ck th

is p

rovi

sion

. Dis

infe

ctio

n of

wat

er s

uppl

ies

com

mon

ly u

ses

oxid

izin

g ag

ents

suc

h as

chl

orin

e or

ozo

ne to

kill

mic

robi

al p

atho

gens

.

Theo

ry o

f kno

wle

dge:

• C

hem

istry

has

dev

elop

ed a

sys

tem

atic

lang

uage

that

has

resu

lted

in o

lder

na

mes

bec

omin

g ob

sole

te. W

hat h

as b

een

lost

and

gai

ned

in th

is p

roce

ss?

• O

xida

tion

stat

es a

re u

sefu

l whe

n ex

plai

ning

redo

x re

actio

ns. A

re a

rtific

ial

conv

ersi

ons

a us

eful

or v

alid

way

of c

larif

ying

kno

wle

dge?

Util

izat

ion:

• A

erob

ic re

spira

tion,

bat

terie

s, s

olar

cel

ls, f

uel c

ells

, ble

achi

ng b

y hy

drog

en

pero

xide

of m

elan

in in

hai

r, ho

useh

old

blea

ch, t

he b

row

ning

of f

ood

expo

sed

to

air,

etc.

• D

rivin

g un

der t

he in

fluen

ce o

f alc

ohol

is a

glo

bal p

robl

em w

hich

resu

lts in

se

rious

road

acc

iden

ts. A

redo

x re

actio

n is

the

basi

s of

the

brea

thal

yser

test

.

• N

atur

al a

nd s

ynth

etic

ant

ioxi

dant

s in

food

che

mis

try.

• P

hoto

chro

mic

lens

es.

• C

orro

sion

and

gal

vani

zatio

n.


Chemistry guide64

9.1

Oxi

datio

n an

d re

duct

ion

• S

olut

ion

of a

rang

e of

redo

x tit

ratio

n pr

oble

ms.

• A

pplic

atio

n of

the

Win

kler

Met

hod

to c

alcu

late

BO

D.

Gui

danc

e:

• O

xida

tion

num

ber a

nd o

xida

tion

stat

e ar

e of

ten

used

inte

rcha

ngea

bly,

thou

gh

IUP

AC

doe

s fo

rmal

ly d

istin

guis

h be

twee

n th

e tw

o te

rms.

Oxi

datio

n nu

mbe

rs

are

repr

esen

ted

by R

oman

num

eral

s ac

cord

ing

to IU

PA

C.

• O

xida

tion

stat

es s

houl

d be

repr

esen

ted

with

the

sign

giv

en b

efor

e th

e nu

mbe

r, eg

+2

not 2

+.

• Th

e ox

idat

ion

stat

e of

hyd

roge

n in

met

al h

ydrid

es (-

1) a

nd o

xyge

n in

per

oxid

es

(-1) s

houl

d be

cov

ered

.

• A

sim

ple

activ

ity s

erie

s is

giv

en in

the

data

boo

klet

in s

ectio

n 25

.

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 1.

3—ex

perim

enta

l det

erm

inat

ion

of a

mou

nts,

mas

ses,

vol

umes

and

co

ncen

tratio

ns o

f sol

utio

ns

Topi

c 3.

2—ha

loge

n re

activ

ity

Topi

cs 4

.1 a

nd 4

.2—

diffe

renc

e be

twee

n io

nic

and

cova

lent

bon

ding

To

pic

10.2

—ox

idat

ion

of a

lcoh

ols

Bio

logy

topi

cs 8

.2 a

nd 8

.3—

redo

x re

actio

ns in

phy

siol

ogy

Aim

s:

• A

im 6

: Exp

erim

ents

cou

ld in

clud

e de

mon

stra

ting

the

activ

ity s

erie

s, re

dox

titra

tions

and

usi

ng th

e W

inkl

er M

etho

d to

mea

sure

BO

D.

• A

im 8

: Oxi

dizi

ng a

gent

s su

ch a

s ch

lorin

e ca

n be

use

d as

dis

infe

ctan

ts. U

se o

f ch

lorin

e as

a d

isin

fect

ant i

s of

con

cern

due

to it

s ab

ility

to o

xidi

ze o

ther

spe

cies

fo

rmin

g ha

rmfu

l by-

prod

ucts

(eg

trich

loro

met

hane

).


Chemistry guide 65

Esse

ntia

l ide

a: V

olta

ic c

ells

con

vert

chem

ical

ene

rgy

to e

lect

rical

ene

rgy

and

elec

troly

tic c

ells

con

vert

elec

trica

l ene

rgy

to c

hem

ical

ene

rgy.

9.2

Elec

troc

hem

ical

cel

ls

Nat

ure

of s

cien

ce:

Eth

ical

impl

icat

ions

of r

esea

rch—

the

desi

re to

pro

duce

ene

rgy

can

be d

riven

by

soci

al n

eeds

or p

rofit

. (4.

5)

Und

erst

andi

ngs:

Vol

taic

(Gal

vani

c) c

ells

:

• V

olta

ic c

ells

con

vert

ener

gy fr

om s

pont

aneo

us, e

xoth

erm

ic c

hem

ical

pro

cess

es

to e

lect

rical

ene

rgy.

• O

xida

tion

occu

rs a

t the

ano

de (n

egat

ive

elec

trode

) and

redu

ctio

n oc

curs

at t

he

cath

ode

(pos

itive

ele

ctro

de) i

n a

volta

ic c

ell.

Ele

ctro

lytic

cel

ls:

• E

lect

roly

tic c

ells

con

vert

elec

trica

l ene

rgy

to c

hem

ical

ene

rgy,

by

brin

ging

abo

ut

non-

spon

tane

ous

proc

esse

s.

• O

xida

tion

occu

rs a

t the

ano

de (p

ositi

ve e

lect

rode

) and

redu

ctio

n oc

curs

at t

he

cath

ode

(neg

ativ

e el

ectro

de) i

n an

ele

ctro

lytic

cel

l.

App

licat

ions

and

ski

lls:

• C

onst

ruct

ion

and

anno

tatio

n of

bot

h ty

pes

of e

lect

roch

emic

al c

ells

.

• E

xpla

natio

n of

how

a re

dox

reac

tion

is u

sed

to p

rodu

ce e

lect

ricity

in a

vol

taic

ce

ll an

d ho

w c

urre

nt is

con

duct

ed in

an

elec

troly

tic c

ell.

• D

istin

ctio

n be

twee

n el

ectro

n an

d io

n flo

w in

bot

h el

ectro

chem

ical

cel

ls.

• P

erfo

rman

ce o

f lab

orat

ory

expe

rimen

ts in

volv

ing

a ty

pica

l vol

taic

cel

l usi

ng tw

o m

etal

/met

al-io

n ha

lf-ce

lls.

• D

educ

tion

of th

e pr

oduc

ts o

f the

ele

ctro

lysi

s of

a m

olte

n sa

lt.

Inte

rnat

iona

l-min

dedn

ess:

• R

esea

rch

in s

pace

exp

lora

tion

ofte

n ce

ntre

s on

ene

rgy

fact

ors.

The

bas

ic

hydr

ogen

–oxy

gen

fuel

cel

l can

be

used

as

an e

nerg

y so

urce

in s

pace

craf

t, su

ch a

s th

ose

first

eng

inee

red

by N

AS

A in

the

US

A. T

he In

tern

atio

nal S

pace

S

tatio

n is

a g

ood

exam

ple

of a

mul

tinat

iona

l pro

ject

invo

lvin

g th

e in

tern

atio

nal

scie

ntifi

c co

mm

unity

.

Theo

ry o

f kno

wle

dge:

• Is

ene

rgy

just

an

abst

ract

con

cept

use

d to

just

ify w

hy c

erta

in ty

pes

of c

hang

es

are

alw

ays

asso

ciat

ed w

ith e

ach

othe

r? A

re c

once

pts

such

as

ener

gy re

al?

Util

izat

ion:

• Fu

el c

ells

.

• H

eart

pace

mak

ers.

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Opt

ion

C.6

—fu

el c

ells

P

hysi

cs to

pic

5.3—

elec

troch

emic

al c

ells

Aim

s:

• A

im 6

: Con

stru

ctio

n of

a ty

pica

l vol

taic

cel

l usi

ng tw

o m

etal

/met

al-io

n ha

lf-ce

lls.

• A

im 6

: Ele

ctro

lysi

s ex

perim

ents

cou

ld in

clud

e th

at o

f a m

olte

n sa

lt. A

vid

eo

coul

d al

so b

e us

ed to

sho

w s

ome

of th

ese

elec

troly

tic p

roce

sses

.


Chemistry guide66

9.2

Elec

troc

hem

ical

cel

ls

Gui

danc

e:

• Fo

r vol

taic

cel

ls, a

cel

l dia

gram

con

vent

ion

shou

ld b

e co

vere

d.

• A

im 8

: Alth

ough

the

hydr

ogen

fuel

cel

l is

cons

ider

ed a

n en

viro

nmen

tally

fri

endl

y, e

ffici

ent a

ltern

ativ

e to

the

inte

rnal

com

bust

ion

engi

ne, s

tora

ge o

f hy

drog

en fu

el is

a m

ajor

pro

blem

. The

use

of l

iqui

d m

etha

nol,

whi

ch c

an b

e pr

oduc

ed fr

om p

lant

s as

a c

arbo

n ne

utra

l fue

l (on

e w

hich

doe

s no

t con

tribu

te to

th

e gr

eenh

ouse

effe

ct),

in fu

el c

ells

has

eno

rmou

s po

tent

ial.

Wha

t are

the

curre

nt b

arrie

rs to

the

deve

lopm

ent o

f fue

l cel

ls?

Topic 10: Organic chemistry


Topi

c 10

: Org

anic

che

mis

try

11 h

ours

Core

Esse

ntia

l ide

a: O

rgan

ic c

hem

istry

focu

ses

on th

e ch

emis

try o

f com

poun

ds c

onta

inin

g ca

rbon

.

10.1

Fun

dam

enta

ls o

f org

anic

che

mis

try

Nat

ure

of s

cien

ce:

Ser

endi

pity

and

sci

entif

ic d

isco

verie

s—P

TFE

and

sup

ergl

ue. (

1.4)

Eth

ical

impl

icat

ions

—dr

ugs,

add

itive

s an

d pe

stic

ides

can

hav

e ha

rmfu

l effe

cts

on b

oth

peop

le a

nd th

e en

viro

nmen

t. (4

.5)

Und

erst

andi

ngs:

• A

hom

olog

ous

serie

s is

a s

erie

s of

com

poun

ds o

f the

sam

e fa

mily

, with

the

sam

e ge

nera

l for

mul

a, w

hich

diff

er fr

om e

ach

othe

r by

a co

mm

on s

truct

ural

un

it.

• S

truct

ural

form

ulas

can

be

repr

esen

ted

in fu

ll an

d co

nden

sed

form

at.

• S

truct

ural

isom

ers

are

com

poun

ds w

ith th

e sa

me

mol

ecul

ar fo

rmul

a bu

t di

ffere

nt a

rrang

emen

ts o

f ato

ms.

• Fu

nctio

nal g

roup

s ar

e th

e re

activ

e pa

rts o

f mol

ecul

es.

• S

atur

ated

com

poun

ds c

onta

in s

ingl

e bo

nds

only

and

uns

atur

ated

com

poun

ds

cont

ain

doub

le o

r trip

le b

onds

.

• B

enze

ne is

an

arom

atic

, uns

atur

ated

hyd

roca

rbon

.

App

licat

ions

and

ski

lls:

• E

xpla

natio

n of

the

trend

s in

boi

ling

poin

ts o

f mem

bers

of a

hom

olog

ous

serie

s.

• D

istin

ctio

n be

twee

n em

piric

al, m

olec

ular

and

stru

ctur

al fo

rmul

as.

Inte

rnat

iona

l-min

dedn

ess:

• A

sm

all p

ropo

rtion

of n

atio

ns h

ave

cont

rol o

ver t

he w

orld

’s o

il re

sour

ces.

The

in

terd

epen

denc

e of

the

coun

tries

that

are

net

impo

rters

and

thos

e th

at a

re n

et

expo

rters

is a

n im

porta

nt fa

ctor

in s

hapi

ng g

loba

l pol

icie

s an

d ec

onom

ic

deve

lopm

ents

.

• Th

e oc

tane

ratin

g (o

ctan

e nu

mbe

r) c

an b

e de

scrib

ed a

s a

stan

dard

mea

sure

of

the

perfo

rman

ce o

f the

fuel

use

d in

car

s an

d ai

rcra

ft. O

ctan

e ra

tings

ofte

n va

ry

quite

wid

ely

regi

onal

ly th

roug

hout

the

glob

e, a

nd a

re c

ompl

icat

ed b

y th

e fa

ct

that

diff

eren

t cou

ntrie

s us

e di

ffere

nt m

eans

of e

xpre

ssin

g th

e va

lues

.

Theo

ry o

f kno

wle

dge:

• Th

e la

bel “

orga

nic

chem

istry

” orig

inat

es fr

om a

mis

conc

eptio

n th

at a

vita

l for

ce

was

nee

ded

to e

xpla

in th

e ch

emis

try o

f life

. Can

you

thin

k of

exa

mpl

es w

here

vo

cabu

lary

has

dev

elop

ed fr

om s

imila

r mis

unde

rsta

ndin

gs?

Can

and

sho

uld

lang

uage

eve

r be

cont

rolle

d to

elim

inat

e su

ch p

robl

ems?

• K

ekul

é cl

aim

ed th

at th

e in

spira

tion

for t

he c

yclic

stru

ctur

e of

ben

zene

cam

e fro

m a

dre

am. W

hat r

ole

do th

e le

ss a

naly

tical

way

s of

kno

wle

dge

play

in th

e ac

quis

ition

of s

cien

tific

kno

wle

dge?

Util

izat

ion:

• Fr

actio

nal d

istil

latio

n m

akes

gre

at u

se o

f man

y pe

troch

emic

als.

• D

yes,

pes

ticid

es, h

erbi

cide

s, e

xplo

sive

s, s

oap,

cos

met

ics,

syn

thet

ic s

cent

s an

d fla

vour

ings

.


Chemistry guide68

10.1

Fun

dam

enta

ls o

f org

anic

che

mis

try

• Id

entif

icat

ion

of d

iffer

ent c

lass

es: a

lkan

es, a

lken

es, a

lkyn

es, h

alog

enoa

lkan

es,

alco

hols

, eth

ers,

ald

ehyd

es, k

eton

es, e

ster

s, c

arbo

xylic

aci

ds, a

min

es, a

mid

es,

nitri

les

and

aren

es.

• Id

entif

icat

ion

of ty

pica

l fun

ctio

nal g

roup

s in

mol

ecul

es e

g ph

enyl

, hyd

roxy

l, ca

rbon

yl, c

arbo

xyl,

carb

oxam

ide,

ald

ehyd

e, e

ster

, eth

er, a

min

e, n

itrile

, alk

yl,

alke

nyl a

nd a

lkyn

yl.

• C

onst

ruct

ion

of 3

-D m

odel

s (r

eal o

r virt

ual)

of o

rgan

ic m

olec

ules

.

• A

pplic

atio

n of

IUP

AC

rule

s in

the

nom

encl

atur

e of

stra

ight

-cha

in a

nd b

ranc

hed-

chai

n is

omer

s.

• Id

entif

icat

ion

of p

rimar

y, s

econ

dary

and

terti

ary

carb

on a

tom

s in

ha

loge

noal

kane

s an

d al

coho

ls a

nd p

rimar

y, s

econ

dary

and

terti

ary

nitro

gen

atom

s in

am

ines

.

• D

iscu

ssio

n of

the

stru

ctur

e of

ben

zene

usi

ng p

hysi

cal a

nd c

hem

ical

evi

denc

e.

Gui

danc

e:

• S

kele

tal f

orm

ulas

sho

uld

be d

iscu

ssed

in th

e co

urse

.

• Th

e ge

nera

l for

mul

as (e

g C

nH2n

+2) o

f alk

anes

, alk

enes

, alk

ynes

, ket

ones

, al

coho

ls, a

ldeh

ydes

and

car

boxy

lic a

cids

sho

uld

be k

now

n.

• Th

e di

stin

ctio

n be

twee

n cl

ass

nam

es a

nd fu

nctio

nal g

roup

nam

es n

eeds

to b

e m

ade.

Eg

for O

H, h

ydro

xyl i

s th

e fu

nctio

nal g

roup

whe

reas

alc

ohol

is th

e cl

ass

nam

e.

• Th

e fo

llow

ing

nom

encl

atur

e sh

ould

be

cove

red:

– no

n-cy

clic

alk

anes

and

hal

ogen

oalk

anes

up

to h

aloh

exan

es.

– al

kene

s up

to h

exen

e an

d al

kyne

s up

to h

exyn

e.

– co

mpo

unds

up

to s

ix c

arbo

n at

oms

(in t

he b

asic

cha

in f

or n

omen

clat

ure

purp

oses

) co

ntai

ning

onl

y on

e of

the

fun

ctio

nal

grou

ps:

hydr

oxyl

, et

her,

carb

onyl

(fro

m a

ldeh

ydes

or k

eton

es),

este

r and

car

boxy

l.

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 1.

2—em

piric

al a

nd m

olec

ular

form

ulas

To

pics

4.2

and

4.3

—Le

wis

(ele

ctro

n do

t) st

ruct

ures

, mul

tiple

bon

ds, V

SE

PR

theo

ry,

reso

nanc

e an

d bo

nd a

nd m

olec

ular

pol

arity

To

pic

4.4—

inte

rmol

ecul

ar fo

rces

To

pic

5.3—

exot

herm

ic re

actio

ns a

nd b

ond

enth

alpi

es

Topi

c 8.

4—w

eak

acid

s O

ptio

n A

.5—

mat

eria

ls a

nd p

olym

ers

Opt

ions

B.2

and

B.7

—pr

otei

ns

Opt

ion

D.9

—or

gani

c st

ruct

ure

in m

edic

ines

Aim

s:

• A

im 6

: Eith

er u

se m

odel

kits

or s

uita

ble

com

pute

r-ge

nera

ted

mol

ecul

ar

grap

hics

pro

gram

mes

to c

onst

ruct

thre

e-di

men

sion

al m

odel

s of

a w

ide

rang

e of

or

gani

c m

olec

ules

.

• A

im 6

: Exp

erim

ents

cou

ld in

clud

e di

still

atio

n to

sep

arat

e liq

uids

or t

he u

se o

f a

rota

ry e

vapo

rato

r to

rem

ove

a so

lven

t fro

m a

mix

ture

.

• A

im 8

: The

re a

re c

onse

quen

ces

in u

sing

foss

il fu

els

as o

ur m

ain

sour

ce o

f en

ergy

. Man

y pr

oduc

ts c

an b

e ob

tain

ed fr

om fo

ssil

fuel

s du

e to

the

inhe

rent

ly

rich

chem

istry

of c

arbo

n. T

his

rais

es s

ome

fund

amen

tal q

uest

ions

—ar

e fo

ssil

fuel

s to

o va

luab

le to

bur

n an

d ho

w d

o th

ey a

ffect

the

envi

ronm

ent?

Who

sho

uld

be re

spon

sibl

e fo

r mak

ing

deci

sion

s in

this

rega

rd?

• A

im 8

: Dis

cuss

the

use

of a

lcoh

ols

and

biof

uels

as

fuel

alte

rnat

ives

to p

etro

l (g

asol

ine)

and

die

sel.


Chemistry guide 69

Esse

ntia

l ide

a: S

truct

ure,

bon

ding

and

che

mic

al re

actio

ns in

volv

ing

func

tiona

l gro

up in

terc

onve

rsio

ns a

re k

ey s

trand

s in

org

anic

che

mis

try.

10.2

Fun

ctio

nal g

roup

che

mis

try

Nat

ure

of s

cien

ce:

Use

of d

ata—

muc

h of

the

prog

ress

that

has

bee

n m

ade

to d

ate

in th

e de

velo

pmen

ts a

nd a

pplic

atio

ns o

f sci

entif

ic re

sear

ch c

an b

e m

appe

d ba

ck to

key

org

anic

che

mic

al

reac

tions

invo

lvin

g fu

nctio

nal g

roup

inte

rcon

vers

ions

. (3.

1)

Und

erst

andi

ngs:

Alk

anes

:

• A

lkan

es h

ave

low

reac

tivity

and

und

ergo

free

-radi

cal s

ubst

itutio

n re

actio

ns.

Alk

enes

:

• A

lken

es a

re m

ore

reac

tive

than

alk

anes

and

und

ergo

add

ition

reac

tions

. B

rom

ine

wat

er c

an b

e us

ed to

dis

tingu

ish

betw

een

alke

nes

and

alka

nes.

Alc

ohol

s:

• A

lcoh

ols

unde

rgo

este

rific

atio

n (o

r con

dens

atio

n) re

actio

ns w

ith a

cids

and

so

me

unde

rgo

oxid

atio

n re

actio

ns.

Hal

ogen

oalk

anes

:

• H

alog

enoa

lkan

es a

re m

ore

reac

tive

than

alk

anes

. The

y ca

n un

derg

o (n

ucle

ophi

lic) s

ubst

itutio

n re

actio

ns. A

nuc

leop

hile

is a

n el

ectro

n-ric

h sp

ecie

s co

ntai

ning

a lo

ne p

air t

hat i

t don

ates

to a

n el

ectro

n-de

ficie

nt c

arbo

n.

Pol

ymer

s:

• A

dditi

on p

olym

ers

cons

ist o

f a w

ide

rang

e of

mon

omer

s an

d fo

rm th

e ba

sis

of

the

plas

tics

indu

stry

.

Ben

zene

:

• B

enze

ne d

oes

not r

eadi

ly u

nder

go a

dditi

on re

actio

ns b

ut d

oes

unde

rgo

elec

troph

ilic

subs

titut

ion

reac

tions

.

Inte

rnat

iona

l-min

dedn

ess:

• M

etha

ne is

a g

reen

hous

e ga

s, a

nd it

s re

leas

e fro

m ru

min

ants

in c

ount

ries

such

as

Bra

zil,

Uru

guay

, Arg

entin

a an

d N

ew Z

eala

nd c

ontri

bute

s si

gnifi

cant

ly to

tota

l gr

eenh

ouse

gas

em

issi

ons.

Lan

dfills

are

als

o a

sour

ce o

f met

hane

, and

te

chno

logi

es a

re d

evel

opin

g in

som

e co

untri

es to

cap

ture

the

gas

as a

sou

rce

of e

nerg

y fo

r ele

ctric

ity a

nd h

eat g

ener

atio

n.

• A

lcoh

ol m

isus

e is

a g

row

ing

prob

lem

in m

any

coun

tries

and

can

hav

e an

im

pact

on

thei

r eco

nom

ies

and

soci

al s

truct

ures

.

Util

izat

ion:

• A

lkan

e us

age

as fu

els.

• Th

e ro

le o

f eth

ene

in fr

uit r

ipen

ing.

• A

lcoh

ols,

usa

ge a

s fu

el a

dditi

ves.

• A

lcoh

ols,

role

in th

e br

eath

alys

er.

• E

ster

s, v

arie

d us

es—

perfu

mes

, foo

d fla

vour

ings

, sol

vent

s, n

itrog

lyce

rin,

biof

uels

and

pai

nkill

ers.

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 9.

1—re

dox

proc

esse

s O

ptio

n A

.5—

poly

mer

s O

ptio

n B

.3—

lipid

s


Chemistry guide70

10.2

Fun

ctio

nal g

roup

che

mis

try

App

licat

ions

and

ski

lls:

Alk

anes

:

• W

ritin

g eq

uatio

ns fo

r the

com

plet

e an

d in

com

plet

e co

mbu

stio

n of

hy

droc

arbo

ns.

• E

xpla

natio

n of

the

reac

tion

of m

etha

ne a

nd e

than

e w

ith h

alog

ens

in te

rms

of a

fre

e-ra

dica

l sub

stitu

tion

mec

hani

sm in

volv

ing

phot

oche

mic

al h

omol

ytic

fiss

ion.

Alk

enes

:

• W

ritin

g eq

uatio

ns fo

r the

reac

tions

of a

lken

es w

ith h

ydro

gen

and

halo

gens

and

of

sym

met

rical

alk

enes

with

hyd

roge

n ha

lides

and

wat

er.

• O

utlin

e of

the

addi

tion

poly

mer

izat

ion

of a

lken

es.

• R

elat

ions

hip

betw

een

the

stru

ctur

e of

the

mon

omer

to th

e po

lym

er a

nd

repe

atin

g un

it.

Alc

ohol

s:

• W

ritin

g eq

uatio

ns fo

r the

com

plet

e co

mbu

stio

n of

alc

ohol

s.

• W

ritin

g eq

uatio

ns fo

r the

oxi

datio

n re

actio

ns o

f prim

ary

and

seco

ndar

y al

coho

ls

(usi

ng a

cidi

fied

pota

ssiu

m d

ichr

omat

e(V

I) or

pot

assi

um m

anga

nate

(VII)

as

oxid

izin

g ag

ents

). E

xpla

natio

n of

dis

tilla

tion

and

reflu

x in

the

isol

atio

n of

the

alde

hyde

and

car

boxy

lic a

cid

prod

ucts

.

• W

ritin

g th

e eq

uatio

n fo

r the

con

dens

atio

n re

actio

n of

an

alco

hol w

ith a

ca

rbox

ylic

aci

d, in

the

pres

ence

of a

cat

alys

t (eg

con

cent

rate

d su

lfuric

aci

d) to

fo

rm a

n es

ter.

Hal

ogen

oalk

anes

:

• W

ritin

g th

e eq

uatio

n fo

r the

sub

stitu

tion

reac

tions

of h

alog

enoa

lkan

es w

ith

aque

ous

sodi

um h

ydro

xide

.

Aim

s:

• A

im 6

: Exp

erim

ents

cou

ld in

clud

e di

stin

guis

hing

bet

wee

n al

kane

s an

d al

kene

s,

prep

arin

g so

ap a

nd th

e us

e of

gra

vity

filtr

atio

n, fi

ltrat

ion

unde

r vac

uum

(usi

ng a

B

uchn

er fl

ask)

, pur

ifica

tion

incl

udin

g re

crys

talli

zatio

n, re

flux

and

dist

illat

ion,

m

eltin

g po

int d

eter

min

atio

n an

d ex

tract

ion.

• A

im 8

: Dis

cuss

the

sign

ifica

nce

of th

e hy

drog

enat

ion

of a

lken

es in

the

food

pr

oduc

tion

incl

udin

g tra

ns-fa

ts a

s by

-pro

duct

s.


Chemistry guide 71

10.2

Fun

ctio

nal g

roup

che

mis

try

Gui

danc

e:

• R

efer

ence

sho

uld

be m

ade

to in

itiat

ion,

pro

paga

tion

and

term

inat

ion

step

s in

fre

e-ra

dica

l sub

stitu

tion

reac

tions

. Fre

e ra

dica

ls s

houl

d be

repr

esen

ted

by a

si

ngle

dot

.

• Th

e m

echa

nism

s of

SN1

and

SN2

and

elec

troph

ilic

subs

titut

ion

reac

tions

are

not

re

quire

d.

Topic 11: Measurement and data processing

Chemistry guide72

Esse

ntia

l ide

a: A

ll m

easu

rem

ent h

as a

lim

it of

pre

cisi

on a

nd a

ccur

acy,

and

this

mus

t be

take

n in

to a

ccou

nt w

hen

eval

uatin

g ex

perim

enta

l res

ults

.

11.1

Unc

erta

intie

s an

d er

rors

in m

easu

rem

ent a

nd re

sults

Nat

ure

of s

cien

ce:

Mak

ing

quan

titat

ive

mea

sure

men

ts w

ith re

plic

ates

to e

nsur

e re

liabi

lity—

prec

isio

n, a

ccur

acy,

sys

tem

atic

, and

rand

om e

rror

s m

ust b

e in

terp

rete

d th

roug

h re

plic

atio

n. (3

.2, 3

.4)

Und

erst

andi

ngs:

• Q

ualit

ativ

e da

ta in

clud

es a

ll no

n-nu

mer

ical

info

rmat

ion

obta

ined

from

ob

serv

atio

ns n

ot fr

om m

easu

rem

ent.

• Q

uant

itativ

e da

ta a

re o

btai

ned

from

mea

sure

men

ts, a

nd a

re a

lway

s as

soci

ated

w

ith ra

ndom

erro

rs/u

ncer

tain

ties,

det

erm

ined

by

the

appa

ratu

s, a

nd b

y hu

man

lim

itatio

ns s

uch

as re

actio

n tim

es.

• P

ropa

gatio

n of

rand

om e

rrors

in d

ata

proc

essi

ng s

how

s th

e im

pact

of t

he

unce

rtain

ties

on th

e fin

al re

sult.

• E

xper

imen

tal d

esig

n an

d pr

oced

ure

usua

lly le

ad to

sys

tem

atic

erro

rs in

m

easu

rem

ent,

whi

ch c

ause

a d

evia

tion

in a

par

ticul

ar d

irect

ion.

• R

epea

t tria

ls a

nd m

easu

rem

ents

will

redu

ce ra

ndom

erro

rs b

ut n

ot s

yste

mat

ic

erro

rs.

App

licat

ions

and

ski

lls:

• D

istin

ctio

n be

twee

n ra

ndom

erro

rs a

nd s

yste

mat

ic e

rrors

.

• R

ecor

d un

certa

intie

s in

all

mea

sure

men

ts a

s a

rang

e (+

) to

an a

ppro

pria

te

prec

isio

n.

• D

iscu

ssio

n of

way

s to

redu

ce u

ncer

tain

ties

in a

n ex

perim

ent.

• P

ropa

gatio

n of

unc

erta

intie

s in

pro

cess

ed d

ata,

incl

udin

g th

e us

e of

per

cent

age

unce

rtain

ties.

• D

iscu

ssio

n of

sys

tem

atic

err

ors

in a

ll ex

perim

enta

l wor

k, th

eir i

mpa

ct o

n th

e re

sults

and

how

they

can

be

redu

ced.

Inte

rnat

iona

l-min

dedn

ess:

• A

s a

resu

lt of

col

labo

ratio

n be

twee

n se

ven

inte

rnat

iona

l org

aniz

atio

ns,

incl

udin

g IU

PA

C, t

he In

tern

atio

nal S

tand

ards

Org

aniz

atio

n (IS

O) p

ublis

hed

the

Gui

de to

the

Exp

ress

ion

of U

ncer

tain

ty in

Mea

sure

men

t in

1995

. Thi

s ha

s be

en

wid

ely

adop

ted

in m

ost c

ount

ries

and

has

been

tran

slat

ed in

to s

ever

al

lang

uage

s.

Theo

ry o

f kno

wle

dge:

• S

cien

ce h

as b

een

desc

ribed

as

a se

lf-co

rrect

ing

and

com

mun

al p

ublic

en

deav

our.

To w

hat e

xten

t do

thes

e ch

arac

teris

tics

also

app

ly to

the

othe

r ar

eas

of k

now

ledg

e?

Util

izat

ion:

• C

rash

of t

he M

ars

Clim

ate

Orb

iter s

pace

craf

t.

• O

rigin

al re

sults

from

CE

RN

rega

rdin

g th

e sp

eed

of n

eutri

nos

wer

e fla

wed

.

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Opt

ion

D.1

—dr

ug tr

ials

Aim

s:

• A

im 6

: The

dis

tinct

ion

and

diffe

rent

role

s of

Cla

ss A

and

Cla

ss B

gla

ssw

are

coul

d be

exp

lore

d.

• A

im 8

: Con

side

r the

mor

al o

blig

atio

ns o

f sci

entis

ts to

com

mun

icat

e th

e fu

ll ex

tent

of t

heir

data

, inc

ludi

ng e

xper

imen

tal u

ncer

tain

ties.

The

“col

d fu

sion

” cas

e of

Fle

isch

man

n an

d P

ons

in th

e 19

90s

is a

n ex

ampl

e of

whe

n th

is w

as n

ot

fulfi

lled.

Core Topi

c 11

: Mea

sure

men

t and

dat

a pr

oces

sing

10 h

ours


Chemistry guide 73

11.1

Unc

erta

intie

s an

d er

rors

in m

easu

rem

ent a

nd re

sults

• E

stim

atio

n of

whe

ther

a p

artic

ular

sou

rce

of e

rror i

s lik

ely

to h

ave

a m

ajor

or

min

or e

ffect

on

the

final

resu

lt.

• C

alcu

latio

n of

per

cent

age

erro

r whe

n th

e ex

perim

enta

l res

ult c

an b

e co

mpa

red

with

a th

eore

tical

or a

ccep

ted

resu

lt.

• D

istin

ctio

n be

twee

n ac

cura

cy a

nd p

reci

sion

in e

valu

atin

g re

sults

.

Gui

danc

e:

• Th

e nu

mbe

r of s

igni

fican

t fig

ures

in a

resu

lt is

bas

ed o

n th

e fig

ures

giv

en in

the

data

. Whe

n ad

ding

or s

ubtra

ctin

g, th

e fin

al a

nsw

er s

houl

d be

giv

en to

the

leas

t nu

mbe

r of d

ecim

al p

lace

s. W

hen

mul

tiply

ing

or d

ivid

ing

the

final

ans

wer

is

give

n to

the

leas

t num

ber o

f sig

nific

ant f

igur

es.

• N

ote

that

the

data

val

ue m

ust b

e re

cord

ed to

the

sam

e pr

ecis

ion

as th

e ra

ndom

er

ror.

• S

I uni

ts s

houl

d be

use

d th

roug

hout

the

prog

ram

me.


Chemistry guide74

Esse

ntia

l ide

a: G

raph

s ar

e a

visu

al re

pres

enta

tion

of tr

ends

in d

ata.

11.2

Gra

phic

al te

chni

ques

Nat

ure

of s

cien

ce:

The

idea

of c

orre

latio

n—ca

n be

test

ed in

exp

erim

ents

who

se re

sults

can

be

disp

laye

d gr

aphi

cally

. (2.

8)

Und

erst

andi

ngs:

• G

raph

ical

tech

niqu

es a

re a

n ef

fect

ive

mea

ns o

f com

mun

icat

ing

the

effe

ct o

f an

inde

pend

ent v

aria

ble

on a

dep

ende

nt v

aria

ble,

and

can

lead

to d

eter

min

atio

n of

ph

ysic

al q

uant

ities

.

• S

ketc

hed

grap

hs h

ave

labe

lled

but u

nsca

led

axes

, and

are

use

d to

sho

w

qual

itativ

e tre

nds,

suc

h as

var

iabl

es th

at a

re p

ropo

rtion

al o

r inv

erse

ly

prop

ortio

nal.

• D

raw

n gr

aphs

hav

e la

belle

d an

d sc

aled

axe

s, a

nd a

re u

sed

in q

uant

itativ

e m

easu

rem

ents

.

App

licat

ions

and

ski

lls:

• D

raw

ing

grap

hs o

f exp

erim

enta

l res

ults

incl

udin

g th

e co

rrect

cho

ice

of a

xes

and

scal

e.

• In

terp

reta

tion

of g

raph

s in

term

s of

the

rela

tions

hips

of d

epen

dent

and

in

depe

nden

t var

iabl

es.

• P

rodu

ctio

n an

d in

terp

reta

tion

of b

est-f

it lin

es o

r cur

ves

thro

ugh

data

poi

nts,

in

clud

ing

an a

sses

smen

t of w

hen

it ca

n an

d ca

nnot

be

cons

ider

ed a

s a

linea

r fu

nctio

n.

• C

alcu

latio

n of

qua

ntiti

es fr

om g

raph

s by

mea

surin

g sl

ope

(gra

dien

t) an

d in

terc

ept,

incl

udin

g ap

prop

riate

uni

ts.

Inte

rnat

iona

l-min

dedn

ess:

• C

harts

and

gra

phs,

whi

ch la

rgel

y tra

nsce

nd la

ngua

ge b

arrie

rs, c

an fa

cilit

ate

com

mun

icat

ion

betw

een

scie

ntis

ts w

orld

wid

e.

Theo

ry o

f kno

wle

dge:

• G

raph

s ar

e a

visu

al re

pres

enta

tion

of d

ata,

and

so

use

sens

e pe

rcep

tion

as a

w

ay o

f kno

win

g. T

o w

hat e

xten

t doe

s th

eir i

nter

pret

atio

n al

so re

ly o

n th

e ot

her

way

s of

kno

win

g, s

uch

as la

ngua

ge a

nd re

ason

?

Util

izat

ion:

• G

raph

ical

repr

esen

tatio

ns o

f dat

a ar

e w

idel

y us

ed in

div

erse

are

as s

uch

as

popu

latio

n, fi

nanc

e an

d cl

imat

e m

odel

ling.

Inte

rpre

tatio

n of

thes

e st

atis

tical

tre

nds

can

ofte

n le

ad to

pre

dict

ions

, and

so

unde

rpin

s th

e se

tting

of

gove

rnm

ent p

olic

ies

in m

any

area

s su

ch a

s he

alth

and

edu

catio

n.

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 1.

3—ga

s vo

lum

e, te

mpe

ratu

re, p

ress

ure

grap

hs

Topi

c 6.

1—M

axw

ell–

Bol

tzm

ann

frequ

ency

dis

tribu

tion;

con

cent

ratio

n–tim

e an

d ra

te–

conc

entra

tion

grap

hs

Topi

c 16

.2—

Arrh

eniu

s pl

ot to

det

erm

ine

activ

atio

n en

ergy

To

pic

18.3

—tit

ratio

n cu

rves

O

ptio

n B

.7—

enzy

me

kine

tics

O

ptio

n C

.5—

gree

nhou

se e

ffect

; car

bon

diox

ide

conc

entra

tion

and

glob

al

tem

pera

ture

s O

ptio

n C

.7—

first

ord

er/d

ecay

gra

ph

Aim

s:

• A

im 7

: Gra

ph-p

lotti

ng s

oftw

are

may

be

used

, inc

ludi

ng th

e us

e of

spr

eads

heet

s an

d th

e de

rivat

ion

of b

est-f

it lin

es a

nd g

radi

ents

.


Chemistry guide 75

Esse

ntia

l ide

a: A

naly

tical

tech

niqu

es c

an b

e us

ed to

det

erm

ine

the

stru

ctur

e of

a c

ompo

und,

ana

lyse

the

com

posi

tion

of a

sub

stan

ce o

r det

erm

ine

the

purit

y of

a c

ompo

und.

S

pect

rosc

opic

tech

niqu

es a

re u

sed

in th

e st

ruct

ural

iden

tific

atio

n of

org

anic

and

inor

gani

c co

mpo

unds

.

11.3

Spe

ctro

scop

ic id

entif

icat

ion

of o

rgan

ic c

ompo

unds

Nat

ure

of s

cien

ce:

Impr

ovem

ents

in in

stru

men

tatio

n—m

ass

spec

trom

etry

, pro

ton

nucl

ear m

agne

tic re

sona

nce

and

infra

red

spec

trosc

opy

have

mad

e id

entif

icat

ion

and

stru

ctur

al d

eter

min

atio

n of

com

poun

ds ro

utin

e. (1

.8)

Mod

els

are

deve

lope

d to

exp

lain

cer

tain

phe

nom

ena

that

may

not

be

obse

rvab

le—

for e

xam

ple,

spe

ctra

are

bas

ed o

n th

e bo

nd v

ibra

tion

mod

el. (

1.10

)

Und

erst

andi

ngs:

• Th

e de

gree

of u

nsat

urat

ion

or in

dex

of h

ydro

gen

defic

ienc

y (IH

D) c

an b

e us

ed

to d

eter

min

e fro

m a

mol

ecul

ar fo

rmul

a th

e nu

mbe

r of r

ings

or m

ultip

le b

onds

in

a m

olec

ule.

• M

ass

spec

trom

etry

(MS

), pr

oton

nuc

lear

mag

netic

reso

nanc

e sp

ectro

scop

y (1 H

N

MR

) and

infra

red

spec

trosc

opy

(IR) a

re te

chni

ques

that

can

be

used

to h

elp

iden

tify

com

poun

ds a

nd to

det

erm

ine

thei

r stru

ctur

e.

App

licat

ions

and

ski

lls:

• D

eter

min

atio

n of

the

IHD

from

a m

olec

ular

form

ula.

• D

educ

tion

of in

form

atio

n ab

out t

he s

truct

ural

feat

ures

of a

com

poun

d fro

m

perc

enta

ge c

ompo

sitio

n da

ta, M

S, 1 H

NM

R o

r IR

.

Gui

danc

e:

• Th

e el

ectro

mag

netic

spe

ctru

m (E

MS

) is

give

n in

the

data

boo

klet

in s

ectio

n 3.

Th

e re

gion

s em

ploy

ed fo

r eac

h te

chni

que

shou

ld b

e un

ders

tood

.

• Th

e op

erat

ing

prin

cipl

es a

re n

ot re

quire

d fo

r any

of t

hese

met

hods

.

Inte

rnat

iona

l-min

dedn

ess:

• M

onito

ring

and

anal

ysis

of t

oxin

s an

d xe

nobi

otic

s in

the

envi

ronm

ent i

s a

cont

inuo

us e

ndea

vour

that

invo

lves

col

labo

ratio

n be

twee

n sc

ient

ists

in d

iffer

ent

coun

tries

.

Theo

ry o

f kno

wle

dge:

• E

lect

rom

agne

tic w

aves

can

tran

smit

info

rmat

ion

beyo

nd th

at o

f our

sen

se

perc

eptio

ns. W

hat a

re th

e lim

itatio

ns o

f sen

se p

erce

ptio

n as

a w

ay o

f kno

win

g?

Util

izat

ion:

• IR

spe

ctro

scop

y is

use

d in

hea

t sen

sors

and

rem

ote

sens

ing

in p

hysi

cs.

• P

roto

ns in

wat

er m

olec

ules

with

in h

uman

cel

ls c

an b

e de

tect

ed b

y m

agne

tic

reso

nanc

e im

agin

g (M

RI),

giv

ing

a th

ree-

dim

ensi

onal

vie

w o

f org

ans

in th

e hu

man

bod

y.

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 1.

2—de

term

inat

ion

of th

e em

piric

al fo

rmul

a fro

m p

erce

ntag

e co

mpo

sitio

n da

ta

or fr

om o

ther

exp

erim

enta

l dat

a an

d de

term

inat

ion

of th

e m

olec

ular

form

ula

from

bo

th th

e em

piric

al fo

rmul

a an

d ex

perim

enta

l dat

a.


Chemistry guide76

11.3

Spe

ctro

scop

ic id

entif

icat

ion

of o

rgan

ic c

ompo

unds

• Th

e da

ta b

ookl

et c

onta

ins

char

acte

ristic

rang

es fo

r IR

abs

orpt

ions

(sec

tion

26),

1 H N

MR

dat

a (s

ectio

n 27

) and

spe

cific

MS

frag

men

ts (s

ectio

n 28

). Fo

r 1 H N

MR

, on

ly th

e ab

ility

to d

educ

e th

e nu

mbe

r of d

iffer

ent h

ydro

gen

(pro

ton)

en

viro

nmen

ts a

nd th

e re

lativ

e nu

mbe

rs o

f hyd

roge

n at

oms

in e

ach

envi

ronm

ent

is re

quire

d. In

tegr

atio

n tra

ces

shou

ld b

e co

vere

d bu

t spl

ittin

g pa

ttern

s ar

e no

t re

quire

d.

Topi

c 2.

1—th

e nu

clea

r ato

m

Topi

c 5.

3—bo

nd e

ntha

lpie

s

Aim

s:

• A

im 7

: Spe

ctra

l dat

abas

es c

ould

be

used

her

e.

• A

im 8

: The

effe

cts

of th

e va

rious

gre

enho

use

gase

s de

pend

on

thei

r ab

unda

nce

and

thei

r abi

lity

to a

bsor

b he

at ra

diat

ion.



Topi

c 12

: Ato

mic

str

uctu

re

2 ho

urs

Add

ition

al h

ighe

r lev

el

Esse

ntia

l ide

a: T

he q

uant

ized

nat

ure

of e

nerg

y tra

nsiti

ons

is re

late

d to

the

ener

gy s

tate

s of

ele

ctro

ns in

ato

ms

and

mol

ecul

es.

12.1

Ele

ctro

ns in

ato

ms

Nat

ure

of s

cien

ce:

Exp

erim

enta

l evi

denc

e to

sup

port

theo

ries—

emis

sion

spe

ctra

pro

vide

evi

denc

e fo

r the

exi

sten

ce o

f ene

rgy

leve

ls. (

1.8)

Und

erst

andi

ngs:

• In

an

emis

sion

spe

ctru

m, t

he li

mit

of c

onve

rgen

ce a

t hig

her f

requ

ency

co

rresp

onds

to th

e fir

st io

niza

tion

ener

gy.

• Tr

ends

in fi

rst i

oniz

atio

n en

ergy

acr

oss

perio

ds a

ccou

nt fo

r the

exi

sten

ce o

f m

ain

ener

gy le

vels

and

sub

-leve

ls in

ato

ms.

• S

ucce

ssiv

e io

niza

tion

ener

gy d

ata

for a

n el

emen

t giv

e in

form

atio

n th

at s

how

s re

latio

ns to

ele

ctro

n co

nfig

urat

ions

.

App

licat

ions

and

ski

lls:

• S

olvi

ng p

robl

ems

usin

g 𝐸𝐸

=ℎ𝑣𝑣

.

• C

alcu

latio

n of

the

valu

e of

the

first

ioni

zatio

n en

ergy

from

spe

ctra

l dat

a w

hich

gi

ves

the

wav

elen

gth

or fr

eque

ncy

of th

e co

nver

genc

e lim

it.

• D

educ

tion

of th

e gr

oup

of a

n el

emen

t fro

m it

s su

cces

sive

ioni

zatio

n en

ergy

da

ta.

• E

xpla

natio

n of

the

trend

s an

d di

scon

tinui

ties

in fi

rst i

oniz

atio

n en

ergy

acr

oss

a pe

riod.

Gui

danc

e:

• Th

e va

lue

of P

lanc

k’s

cons

tant

(h) a

nd 𝐸𝐸

=ℎ𝑣𝑣

are

giv

en in

the

data

boo

klet

in

sect

ions

1 a

nd 2

.

• U

se o

f the

Ryd

berg

form

ula

is n

ot e

xpec

ted

in c

alcu

latio

ns o

f ion

izat

ion

ener

gy.

Inte

rnat

iona

l-min

dedn

ess:

• In

201

2 tw

o se

para

te in

tern

atio

nal t

eam

s w

orki

ng a

t the

Lar

ge H

adro

n C

ollid

er

at C

ER

N in

depe

nden

tly a

nnou

nced

that

they

had

dis

cove

red

a pa

rticl

e w

ith

beha

viou

r con

sist

ent w

ith th

e pr

evio

usly

pre

dict

ed “H

iggs

bos

on”.

Theo

ry o

f kno

wle

dge:

• “W

hat w

e ob

serv

e is

not

nat

ure

itsel

f, bu

t nat

ure

expo

sed

to o

ur m

etho

d of

qu

estio

ning

.”—W

erne

r Hei

senb

erg.

An

elec

tron

can

beha

ve a

s a

wav

e or

a

parti

cle

depe

ndin

g on

the

expe

rimen

tal c

ondi

tions

. Can

sen

se p

erce

ptio

n gi

ve

us o

bjec

tive

know

ledg

e ab

out t

he w

orld

?

• Th

e de

Bro

glie

equ

atio

n sh

ows

that

mac

rosc

opic

par

ticle

s ha

ve to

o sh

ort a

w

avel

engt

h fo

r the

ir w

ave

prop

ertie

s to

be

obse

rved

. Is

it m

eani

ngfu

l to

talk

of

prop

ertie

s w

hich

can

nev

er b

e ob

serv

ed fr

om s

ense

per

cept

ion?

Util

izat

ion:

• El

ectro

n m

icro

scop

y ha

s le

d to

man

y ad

vanc

es in

bio

logy

, suc

h as

the

ultra

stru

ctur

e of

cel

ls a

nd v

iruse

s. T

he s

cann

ing

tunn

ellin

g m

icro

scop

e (S

TM) u

ses

a st

ylus

of a

sin

gle

atom

to s

can

a su

rface

and

pro

vide

a 3-

D im

age

at th

e at

omic

leve

l.

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 3.

2—pe

riodi

c tre

nds

Topi

c 4.

1—io

nic

bond

ing

Topi

c 15

.1—

latti

ce e

ntha

lpy

Aim

s:

• Ai

m 7

: Dat

abas

es c

ould

be

used

for c

ompi

ling

grap

hs o

f tre

nds

in io

niza

tion

ener

gies

an

d sim

ulat

ions

are

ava

ilabl

e fo

r the

Dav

isson

-Ger

mer

ele

ctro

n di

ffrac

tion

expe

rimen

t.

Topic 13: The periodic table—the transition metals

Chemistry guide78

Esse

ntia

l ide

a: T

he tr

ansi

tion

elem

ents

hav

e ch

arac

teris

tic p

rope

rties

; the

se p

rope

rties

are

rela

ted

to th

eir a

ll ha

ving

inco

mpl

ete

d su

blev

els.

13.1

Firs

t-row

d-b

lock

ele

men

ts

Nat

ure

of s

cien

ce:

Look

ing

for t

rend

s an

d di

scre

panc

ies—

trans

ition

ele

men

ts fo

llow

cer

tain

pat

tern

s of

beh

avio

ur. T

he e

lem

ents

Zn,

Cr a

nd C

u do

not

follo

w th

ese

patte

rns

and

are

ther

efor

e co

nsid

ered

ano

mal

ous

in th

e fir

st-ro

w d

-blo

ck. (

3.1)

Und

erst

andi

ngs:

• Tr

ansi

tion

elem

ents

hav

e va

riabl

e ox

idat

ion

stat

es, f

orm

com

plex

ions

with

lig

ands

, hav

e co

lour

ed c

ompo

unds

, and

dis

play

cat

alyt

ic a

nd m

agne

tic

prop

ertie

s.

• Zn

is n

ot c

onsi

dere

d to

be

a tra

nsiti

on e

lem

ent a

s it

does

not

form

ions

with

in

com

plet

e d-

orbi

tals

.

• Tr

ansi

tion

elem

ents

sho

w a

n ox

idat

ion

stat

e of

+2

whe

n th

e s-

elec

trons

are

re

mov

ed.

App

licat

ions

and

ski

lls:

• E

xpla

natio

n of

the

abili

ty o

f tra

nsiti

on m

etal

s to

form

var

iabl

e ox

idat

ion

stat

es

from

suc

cess

ive

ioni

zatio

n en

ergi

es.

• E

xpla

natio

n of

the

natu

re o

f the

coo

rdin

ate

bond

with

in a

com

plex

ion.

• D

educ

tion

of th

e to

tal c

harg

e gi

ven

the

form

ula

of th

e io

n an

d lig

ands

pre

sent

.

• E

xpla

natio

n of

the

mag

netic

pro

perti

es in

tran

sitio

n m

etal

s in

term

s of

unp

aire

d el

ectro

ns.

Gui

danc

e:

• C

omm

on o

xida

tion

char

ges

on tr

ansi

tion

met

al io

ns a

re g

iven

in s

ectio

n 9

of th

e da

ta b

ookl

et, a

nd c

omm

on o

xida

tion

stat

es a

re g

iven

in s

ectio

n 14

.

Inte

rnat

iona

l-min

dedn

ess:

• Th

e pr

oper

ties

and

uses

of t

he tr

ansi

tion

met

als

mak

e th

em im

porta

nt

inte

rnat

iona

l com

mod

ities

. Min

ing

for p

reci

ous

met

als

is a

maj

or fa

ctor

in th

e ec

onom

ies

of s

ome

coun

tries

.

Theo

ry o

f kno

wle

dge:

• Th

e m

edic

al s

ymbo

ls fo

r fem

ale

and

mal

e or

igin

ate

from

the

alch

emic

al

sym

bols

for c

oppe

r and

iron

. Wha

t rol

e ha

s th

e ps

eudo

scie

nce

of a

lche

my

play

ed in

the

deve

lopm

ent o

f mod

ern

scie

nce?

Util

izat

ion:

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 9.

1—re

dox

reac

tions

To

pic

10.2

—ox

idat

ion

of a

lcoh

ols,

hyd

roge

natio

n of

alk

enes

O

ptio

n A

.3—

hom

ogen

eous

and

het

erog

eneo

us c

atal

ysis

Aim

s:

• A

im 6

: The

oxi

datio

n st

ates

of v

anad

ium

and

man

gane

se, f

or e

xam

ple,

cou

ld b

e in

vest

igat

ed e

xper

imen

tally

. Tra

nsiti

on m

etal

s co

uld

be a

naly

sed

usin

g re

dox

titra

tions

.

• A

im 8

: Eco

nom

ic im

pact

of t

he c

orro

sion

of i

ron.

Topi

c 13

: The

per

iodi

c ta

ble—

the

tran

sitio

n m

etal

s 4

hour

s

Add

ition

al h

ighe

r lev

el


Chemistry guide 79

Esse

ntia

l ide

a: d

-orb

itals

hav

e th

e sa

me

ener

gy in

an

isol

ated

ato

m, b

ut s

plit

into

two

sub-

leve

ls in

a c

ompl

ex io

n. T

he e

lect

ric fi

eld

of li

gand

s m

ay c

ause

the

d-or

bita

ls in

co

mpl

ex io

ns to

spl

it so

that

the

ener

gy o

f an

elec

tron

trans

ition

bet

wee

n th

em c

orre

spon

ds to

a p

hoto

n of

vis

ible

ligh

t.

13.2

Col

oure

d co

mpl

exes

Nat

ure

of s

cien

ce:

Mod

els

and

theo

ries—

the

colo

ur o

f tra

nsiti

on m

etal

com

plex

es c

an b

e ex

plai

ned

thro

ugh

the

use

of m

odel

s an

d th

eorie

s ba

sed

on h

ow e

lect

rons

are

dis

tribu

ted

in d

-orb

itals

. (1

.10)

Tran

sdis

cipl

inar

y—co

lour

link

ed to

sym

met

ry c

an b

e ex

plor

ed in

the

scie

nces

, arc

hite

ctur

e, a

nd th

e ar

ts. (

4.1)

Und

erst

andi

ngs:

• Th

e d

sub-

leve

l spl

its in

to tw

o se

ts o

f orb

itals

of d

iffer

ent e

nerg

y in

a c

ompl

ex

ion.

• C

ompl

exes

of d

-blo

ck e

lem

ents

are

col

oure

d, a

s lig

ht is

abs

orbe

d w

hen

an

elec

tron

is e

xcite

d be

twee

n th

e d-

orbi

tals

.

• Th

e co

lour

abs

orbe

d is

com

plem

enta

ry to

the

colo

ur o

bser

ved.

App

licat

ions

and

ski

lls:

• E

xpla

natio

n of

the

effe

ct o

f the

iden

tity

of th

e m

etal

ion,

the

oxid

atio

n nu

mbe

r of

the

met

al a

nd th

e id

entit

y of

the

ligan

d on

the

colo

ur o

f tra

nsiti

on m

etal

ion

com

plex

es.

• E

xpla

natio

n of

the

effe

ct o

f diff

eren

t lig

ands

on

the

split

ting

of th

e d-

orbi

tals

in

trans

ition

met

al c

ompl

exes

and

col

our o

bser

ved

usin

g th

e sp

ectro

chem

ical

se

ries.

Gui

danc

e:

• Th

e sp

ectro

chem

ical

ser

ies

is g

iven

in th

e da

ta b

ookl

et in

sec

tion

15. A

list

of

poly

dent

ate

ligan

ds is

giv

en in

the

data

boo

klet

in s

ectio

n 16

.

• S

tude

nts

are

not e

xpec

ted

to re

call

the

colo

ur o

f spe

cific

com

plex

ions

.

Util

izat

ion:

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 2.

2—el

ectro

n co

nfig

urat

ion

of a

tom

s an

d io

ns

Aim

s:

• A

im 6

: The

col

ours

of a

rang

e of

com

plex

ions

, of e

lem

ents

suc

h as

Cr,

Fe, C

o,

Ni a

nd C

u co

uld

be in

vest

igat

ed.

• A

im 7

: Com

plex

ions

cou

ld b

e in

vest

igat

ed u

sing

a s

pect

rom

eter

dat

a lo

gger

.

• A

im 8

: The

con

cent

ratio

n of

toxi

c tra

nsiti

on m

etal

ions

nee

ds to

be

care

fully

m

onito

red

in e

nviro

nmen

tal s

yste

ms.


Chemistry guide80

13.2

Col

oure

d co

mpl

exes

• Th

e re

latio

n be

twee

n th

e co

lour

obs

erve

d an

d ab

sorb

ed is

illu

stra

ted

by th

e co

lour

whe

el in

the

data

boo

klet

in s

ectio

n 17

.

• S

tude

nts

are

not e

xpec

ted

to k

now

the

diffe

rent

spl

ittin

g pa

ttern

s an

d th

eir

rela

tion

to th

e co

ordi

natio

n nu

mbe

r. O

nly

the

split

ting

of th

e 3d

orb

itals

in a

n oc

tahe

dral

cry

stal

fiel

d is

requ

ired.



Topi

c 14

: Che

mic

al b

ondi

ng a

nd s

truc

ture

7

hour

s

Add

ition

al h

ighe

r lev

el

Esse

ntia

l ide

a: L

arge

r stru

ctur

es a

nd m

ore

in-d

epth

exp

lana

tions

of b

ondi

ng s

yste

ms

ofte

n re

quire

mor

e so

phis

ticat

ed c

once

pts

and

theo

ries

of b

ondi

ng.

14.1

Fur

ther

asp

ects

of c

oval

ent b

ondi

ng a

nd s

truc

ture

Nat

ure

of s

cien

ce:

Prin

cipl

e of

Occ

am’s

razo

r—bo

ndin

g th

eorie

s ha

ve b

een

mod

ified

ove

r tim

e. N

ewer

theo

ries

need

to re

mai

n as

sim

ple

as p

ossi

ble

whi

le m

axim

izin

g ex

plan

ator

y po

wer

, for

ex

ampl

e th

e id

ea o

f for

mal

cha

rge.

(2.7

)

Und

erst

andi

ngs:

• C

oval

ent b

onds

resu

lt fro

m th

e ov

erla

p of

ato

mic

orb

itals

. A s

igm

a bo

nd (

) is

form

ed b

y th

e di

rect

hea

d-on

/end

-to-e

nd o

verla

p of

ato

mic

orb

itals

, res

ultin

g in

el

ectro

n de

nsity

con

cent

rate

d be

twee

n th

e nu

clei

of t

he b

ondi

ng a

tom

s. A

pi

bond

(π) i

s fo

rmed

by

the

side

way

s ov

erla

p of

ato

mic

orb

itals

, res

ultin

g in

el

ectro

n de

nsity

abo

ve a

nd b

elow

the

plan

e of

the

nucl

ei o

f the

bon

ding

ato

ms.

• Fo

rmal

cha

rge

(FC

) can

be

used

to d

ecid

e w

hich

Lew

is (e

lect

ron

dot)

stru

ctur

e is

pre

ferre

d fro

m s

ever

al. T

he F

C is

the

char

ge a

n at

om w

ould

hav

e if

all a

tom

s in

the

mol

ecul

e ha

d th

e sa

me

elec

trone

gativ

ity. F

C =

(Num

ber o

f val

ence

el

ectro

ns)-½

(Num

ber o

f bon

ding

ele

ctro

ns)-

(Num

ber o

f non

-bon

ding

el

ectro

ns).

The

Lew

is (e

lect

ron

dot)

stru

ctur

e w

ith th

e at

oms

havi

ng F

C v

alue

s cl

oses

t to

zero

is p

refe

rred.

• E

xcep

tions

to th

e oc

tet r

ule

incl

ude

som

e sp

ecie

s ha

ving

inco

mpl

ete

octe

ts

and

expa

nded

oct

ets.

• D

eloc

aliz

atio

n in

volv

es e

lect

rons

that

are

sha

red

by/b

etw

een

mor

e th

an o

ne

pair

in a

mol

ecul

e or

ion

as o

ppos

ed to

bei

ng lo

caliz

ed b

etw

een

a pa

ir of

at

oms.

• R

eson

ance

invo

lves

usi

ng tw

o or

mor

e Le

wis

(ele

ctro

n do

t) st

ruct

ures

to

repr

esen

t a p

artic

ular

mol

ecul

e or

ion.

A re

sona

nce

stru

ctur

e is

one

of t

wo

or

mor

e al

tern

ativ

e Le

wis

(ele

ctro

n do

t) st

ruct

ures

for a

mol

ecul

e or

ion

that

ca

nnot

be

desc

ribed

fully

with

one

Lew

is (e

lect

ron

dot)

stru

ctur

e al

one.

Inte

rnat

iona

l-min

dedn

ess:

• H

ow h

as o

zone

dep

letio

n ch

ange

d ov

er ti

me?

Wha

t hav

e w

e do

ne a

s a

glob

al

com

mun

ity to

redu

ce o

zone

dep

letio

n?

• To

wha

t ext

ent i

s oz

one

depl

etio

n an

exa

mpl

e of

bot

h a

succ

ess

and

a fa

ilure

fo

r sol

ving

an

inte

rnat

iona

l env

ironm

enta

l con

cern

?

Theo

ry o

f kno

wle

dge:

• C

oval

ent b

ondi

ng c

an b

e de

scrib

ed u

sing

val

ence

bon

d or

mol

ecul

ar o

rbita

l th

eory

. To

wha

t ext

ent i

s ha

ving

alte

rnat

ive

way

s of

des

crib

ing

the

sam

e ph

enom

ena

a st

reng

th o

r a w

eakn

ess?

Util

izat

ion:

• D

rug

actio

n an

d lin

ks to

a m

olec

ule’

s st

ruct

ure.

• V

isio

n sc

ienc

e an

d lin

ks to

a m

olec

ule’

s st

ruct

ure.

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

cs 4

.2 a

nd 4

.3—

Lew

is (e

lect

ron

dot)

stru

ctur

es, V

SEP

R th

eory

, res

onan

ce a

nd

bond

and

mol

ecul

ar p

olar

ity

Topi

c 10

.1—

shap

es o

f org

anic

mol

ecul

es

Topi

c 13

.1—

trans

ition

met

al c

hem

istry


Chemistry guide82

14.1

Fur

ther

asp

ects

of c

oval

ent b

ondi

ng a

nd s

truc

ture

App

licat

ions

and

ski

lls:

• P

redi

ctio

n w

heth

er s

igm

a (

) or p

i (π

) bon

ds a

re fo

rmed

from

the

linea

r co

mbi

natio

n of

ato

mic

orb

itals

.

• D

educ

tion

of th

e Le

wis

(ele

ctro

n do

t) st

ruct

ures

of m

olec

ules

and

ions

sho

win

g al

l val

ence

ele

ctro

ns fo

r up

to s

ix e

lect

ron

pairs

on

each

ato

m.

• A

pplic

atio

n of

FC

to a

scer

tain

whi

ch L

ewis

(ele

ctro

n do

t) st

ruct

ure

is p

refe

rred

from

diff

eren

t Lew

is (e

lect

ron

dot)

stru

ctur

es.

• D

educ

tion

usin

g VS

EP

R th

eory

of t

he e

lect

ron

dom

ain

geom

etry

and

mol

ecul

ar

geom

etry

with

five

and

six

ele

ctro

n do

mai

ns a

nd a

ssoc

iate

d bo

nd a

ngle

s.

• E

xpla

natio

n of

the

wav

elen

gth

of li

ght r

equi

red

to d

isso

ciat

e ox

ygen

and

ozo

ne.

• D

escr

iptio

n of

the

mec

hani

sm o

f the

cat

alys

is o

f ozo

ne d

eple

tion

whe

n ca

taly

sed

by C

FCs

and

NO

x.

Gui

danc

e:

• Th

e lin

ear c

ombi

natio

n of

ato

mic

orb

itals

to fo

rm m

olec

ular

orb

itals

sho

uld

be

cove

red

in th

e co

ntex

t of t

he fo

rmat

ion

of s

igm

a (

) and

pi (

π) b

onds

.

• M

olec

ular

pol

ariti

es o

f geo

met

ries

corre

spon

ding

to fi

ve a

nd s

ix e

lect

ron

dom

ains

sho

uld

also

be

cove

red.

Aim

s:

• A

im 1

: Glo

bal i

mpa

ct o

f ozo

ne d

eple

tion.

• A

im 7

: Com

pute

r sim

ulat

ions

can

be

used

to m

odel

stru

ctur

es p

redi

cted

by

VS

EP

R th

eory

.

• A

im 8

: Mor

al, e

thic

al, s

ocia

l, ec

onom

ic a

nd e

nviro

nmen

tal i

mpl

icat

ions

of

ozon

e de

plet

ion

and

its s

olut

ion.


Chemistry guide 83

Esse

ntia

l ide

a: H

ybrid

izat

ion

resu

lts fr

om th

e m

ixin

g of

ato

mic

orb

itals

to fo

rm th

e sa

me

num

ber o

f new

equ

ival

ent h

ybrid

orb

itals

that

can

hav

e th

e sa

me

mea

n en

ergy

as

the

cont

ribut

ing

atom

ic o

rbita

ls.

14.2

Hyb

ridiz

atio

n

Nat

ure

of s

cien

ce:

The

need

to re

gard

theo

ries

as u

ncer

tain

—hy

brid

izat

ion

in v

alen

ce b

ond

theo

ry c

an h

elp

expl

ain

mol

ecul

ar g

eom

etrie

s, b

ut is

lim

ited.

Qua

ntum

mec

hani

cs in

volv

es s

ever

al

theo

ries

expl

aini

ng th

e sa

me

phen

omen

a, d

epen

ding

on

spec

ific

requ

irem

ents

. (2.

2)

Und

erst

andi

ngs:

• A

hyb

rid o

rbita

l res

ults

from

the

mix

ing

of d

iffer

ent t

ypes

of a

tom

ic o

rbita

ls o

n th

e sa

me

atom

.

App

licat

ions

:

• E

xpla

natio

n of

the

form

atio

n of

sp3 ,

sp2 a

nd s

p hy

brid

orb

itals

in m

etha

ne,

ethe

ne a

nd e

thyn

e.

• Id

entif

icat

ion

and

expl

anat

ion

of th

e re

latio

nshi

ps b

etw

een

Lew

is (e

lect

ron

dot)

stru

ctur

es, e

lect

ron

dom

ains

, mol

ecul

ar g

eom

etrie

s an

d ty

pes

of h

ybrid

izat

ion.

Gui

danc

e:

• S

tude

nts

need

onl

y co

nsid

er s

peci

es w

ith s

p3 , sp

2 and

sp

hybr

idiz

atio

n.

Theo

ry o

f kno

wle

dge:

• H

ybrid

izat

ion

is a

mat

hem

atic

al d

evic

e w

hich

allo

ws

us to

rela

te th

e bo

ndin

g in

a

mol

ecul

e to

its

sym

met

ry. W

hat i

s th

e re

latio

nshi

p be

twee

n th

e na

tura

l sc

ienc

es, m

athe

mat

ics

and

the

natu

ral w

orld

? W

hich

role

doe

s sy

mm

etry

pla

y in

the

diffe

rent

are

as o

f kno

wle

dge?

Util

izat

ion:

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 4.

3—Le

wis

(ele

ctro

n do

t) st

ruct

ures

, VS

EP

R th

eory

, res

onan

ce a

nd b

ond

and

mol

ecul

ar p

olar

ity

Topi

c 10

.1—

shap

es o

f org

anic

mol

ecul

es

Topi

c 13

.1—

trans

ition

met

al c

hem

istry

Aim

s:

• A

im 7

: Com

pute

r sim

ulat

ions

cou

ld b

e us

ed to

mod

el h

ybrid

orb

itals

.


Chemistry guide84

Esse

ntia

l ide

a: T

he c

once

pt o

f the

ene

rgy

chan

ge in

a s

ingl

e st

ep r

eact

ion

bein

g eq

uiva

lent

to th

e su

mm

atio

n of

sm

alle

r st

eps

can

be a

pplie

d to

cha

nges

invo

lvin

g io

nic

com

poun

ds.

15.1

Ene

rgy

cycl

es

Nat

ure

of s

cien

ce:

Mak

ing

quan

titat

ive

mea

sure

men

ts w

ith re

plic

ates

to e

nsur

e re

liabi

lity—

ener

gy c

ycle

s al

low

for t

he c

alcu

latio

n of

val

ues

that

can

not b

e de

term

ined

dire

ctly

. (3.

2)

Und

erst

andi

ngs:

• R

epre

sent

ativ

e eq

uatio

ns (e

g M

+ (g)

M+ (a

q)) c

an b

e us

ed fo

r ent

halp

y/en

ergy

of

hydr

atio

n, io

niza

tion,

ato

miza

tion,

ele

ctro

n af

finity

, lat

tice,

cov

alen

t bon

d an

d so

lutio

n.

• E

ntha

lpy

of s

olut

ion,

hyd

ratio

n en

thal

py a

nd la

ttice

ent

halp

y ar

e re

late

d in

an

ener

gy c

ycle

.

App

licat

ions

and

ski

lls:

• C

onst

ruct

ion

of B

orn-

Hab

er c

ycle

s fo

r gro

up 1

and

2 o

xide

s an

d ch

lorid

es.

• C

onst

ruct

ion

of e

nerg

y cy

cles

from

hyd

ratio

n, la

ttice

and

sol

utio

n en

thal

py. F

or

exam

ple

diss

olut

ion

of s

olid

NaO

H o

r NH

4Cl i

n w

ater

.

• C

alcu

latio

n of

ent

halp

y ch

ange

s fro

m B

orn-

Hab

er o

r dis

solu

tion

ener

gy c

ycle

s.

• R

elat

e si

ze a

nd c

harg

e of

ions

to la

ttice

and

hyd

ratio

n en

thal

pies

.

• P

erfo

rm la

b ex

perim

ents

whi

ch c

ould

incl

ude

sing

le re

plac

emen

t rea

ctio

ns in

aq

ueou

s so

lutio

ns.

Gui

danc

e:

• P

olar

izin

g ef

fect

of s

ome

ions

pro

duci

ng c

oval

ent c

hara

cter

in s

ome

larg

ely

ioni

c su

bsta

nces

will

not

be

asse

ssed

.

• Th

e fo

llow

ing

enth

alpy

/ene

rgy

term

s sh

ould

be

cove

red:

ioni

zatio

n, a

tom

izat

ion,

el

ectro

n af

finity

, lat

tice,

cov

alen

t bon

d, h

ydra

tion

and

solu

tion.

• V

alue

for l

attic

e en

thal

pies

(sec

tion

18),

enth

alpi

es o

f aqu

eous

sol

utio

ns

(sec

tion

19) a

nd e

ntha

lpie

s of

hyd

ratio

n (s

ectio

n 20

) are

giv

en in

the

data

bo

okle

t.

Inte

rnat

iona

l-min

dedn

ess:

• Th

e im

porta

nce

of b

eing

abl

e to

obt

ain

mea

sure

men

ts o

f som

ethi

ng w

hich

ca

nnot

be

mea

sure

d di

rect

ly is

sig

nific

ant e

very

whe

re. B

oreh

ole

tem

pera

ture

s,

snow

cov

er d

epth

, gla

cier

rece

ssio

n, ra

tes

of e

vapo

ratio

n an

d pr

ecip

itatio

n cy

cles

are

am

ong

som

e in

dire

ct in

dica

tors

of g

loba

l war

min

g. W

hy is

it

impo

rtant

for c

ount

ries

to c

olla

bora

te to

com

bat g

loba

l pro

blem

s lik

e gl

obal

w

arm

ing?

Util

izat

ion:

• O

ther

ene

rgy

cycl

es—

carb

on c

ycle

, the

Kre

bs c

ycle

and

ele

ctro

n tra

nsfe

r in

biol

ogy.

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

cs 1

.2 a

nd 1

.3—

stoi

chio

met

ric re

latio

nshi

ps

Topi

c 3.

2—io

niza

tion

ener

gy, a

tom

ic a

nd io

nic

radi

i To

pic

5.3—

bond

ent

halp

y

Aim

s:

• A

im 4

: Dis

cuss

the

sour

ce o

f acc

epte

d va

lues

and

use

this

idea

to c

ritiq

ue

expe

rimen

ts.

• A

im 6

: A p

ossi

ble

expe

rimen

t is

to c

alcu

late

eith

er th

e en

thal

py o

f cr

ysta

lliza

tion

of w

ater

or t

he h

eat c

apac

ity o

f wat

er w

hen

a cu

be o

f ice

is

adde

d to

hot

wat

er.

• A

im 7

: Use

of d

ata

logg

ers

to re

cord

tem

pera

ture

cha

nges

. Use

of d

atab

ases

to

sou

rce

acce

pted

val

ues.

Topi

c 15

: Ene

rget

ics/

ther

moc

hem

istr

y 7

hour

s

Add

ition

al h

ighe

r lev

el


Chemistry guide 85

Esse

ntia

l ide

a: A

reac

tion

is s

pont

aneo

us if

the

over

all t

rans

form

atio

n le

ads

to a

n in

crea

se in

tota

l ent

ropy

(sys

tem

plu

s su

rroun

ding

s). T

he d

irect

ion

of s

pont

aneo

us c

hang

e al

way

s in

crea

ses

the

tota

l ent

ropy

of t

he u

nive

rse

at th

e ex

pens

e of

ene

rgy

avai

labl

e to

do

usef

ul w

ork.

Thi

s is

kno

wn

as th

e se

cond

law

of t

herm

odyn

amic

s.

15.2

Ent

ropy

and

spo

ntan

eity

Nat

ure

of s

cien

ce:

Theo

ries

can

be s

uper

sede

d—th

e id

ea o

f ent

ropy

has

evo

lved

thro

ugh

the

year

s as

a re

sult

of d

evel

opm

ents

in s

tatis

tics

and

prob

abili

ty. (

2.2)

Und

erst

andi

ngs:

• E

ntro

py (S

) ref

ers

to th

e di

strib

utio

n of

ava

ilabl

e en

ergy

am

ong

the

parti

cles

. Th

e m

ore

way

s th

e en

ergy

can

be

dist

ribut

ed th

e hi

gher

the

entro

py.

• G

ibbs

free

ene

rgy

(G) r

elat

es th

e en

ergy

that

can

be

obta

ined

from

a c

hem

ical

re

actio

n to

the

chan

ge in

ent

halp

y (Δ

H),

chan

ge in

ent

ropy

(ΔS

), an

d ab

solu

te

tem

pera

ture

(T).

• E

ntro

py o

f gas

>liq

uid>

solid

und

er s

ame

cond

ition

s.

App

licat

ions

and

ski

lls:

• P

redi

ctio

n of

whe

ther

a c

hang

e w

ill re

sult

in a

n in

crea

se o

r dec

reas

e in

ent

ropy

by

con

side

ring

the

stat

es o

f the

reac

tant

s an

d pr

oduc

ts.

• C

alcu

latio

n of

ent

ropy

cha

nges

(ΔS

) fro

m g

iven

sta

ndar

d en

tropy

val

ues

(Sº)

.

• A

pplic

atio

n of

∆𝐺𝐺°

= ∆

𝐻𝐻° −𝑇𝑇∆

𝑆𝑆° in p

redi

ctin

g sp

onta

neity

and

cal

cula

tion

of

vario

us c

ondi

tions

of e

ntha

lpy

and

tem

pera

ture

that

will

affe

ct th

is.

• R

elat

ion

of Δ

G to

pos

ition

of e

quili

briu

m.

Gui

danc

e:

• E

xam

ine

vario

us re

actio

n co

nditi

ons

that

affe

ct Δ

G.

• Δ

G is

a c

onve

nien

t way

to ta

ke in

to a

ccou

nt b

oth

the

dire

ct e

ntro

py c

hang

e re

sulti

ng fr

om th

e tra

nsfo

rmat

ion

of th

e ch

emic

als,

and

the

indi

rect

ent

ropy

ch

ange

of t

he s

urro

undi

ngs

as a

resu

lt of

the

gain

/loss

of h

eat e

nerg

y.

• Th

erm

odyn

amic

dat

a is

giv

en in

sec

tion

12 o

f the

dat

a bo

okle

t.

Inte

rnat

iona

l-min

dedn

ess:

• S

usta

inab

le e

nerg

y is

a U

N in

itiat

ive

with

a g

oal o

f dou

blin

g of

glo

bal

sust

aina

ble

ener

gy re

sour

ces

by 2

030.

Theo

ry o

f kno

wle

dge:

• E

ntro

py is

a te

chni

cal t

erm

whi

ch h

as a

pre

cise

mea

ning

. How

impo

rtant

are

su

ch te

chni

cal t

erm

s in

diff

eren

t are

as o

f kno

wle

dge?

Util

izat

ion:

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 5.

2—H

ess’

s La

w

Topi

c 5.

3—bo

nd e

ntha

lpy

Topi

c 7.

1—eq

uilib

rium

O

ptio

n C

.1—

qual

ity o

f ene

rgy

Phy

sics

opt

ion

B.2

—th

erm

odyn

amic

s

Aim

s:

• A

ims

1, 4

and

7: U

se o

f dat

abas

es to

rese

arch

hyp

othe

tical

reac

tions

cap

able

of

gen

erat

ing

free

ener

gy.

• A

im 6

: Exp

erim

ents

inve

stig

atin

g en

doth

erm

ic a

nd e

xoth

erm

ic p

roce

sses

cou

ld

be ru

n nu

mer

ous

times

to c

ompa

re re

liabi

lity

of re

petit

ive

data

and

com

pare

to

theo

retic

al v

alue

s.


Chemistry guide86

Esse

ntia

l ide

a: R

ate

expr

essi

ons

can

only

be

dete

rmin

ed e

mpi

rical

ly a

nd th

ese

limit

poss

ible

reac

tion

mec

hani

sms.

In p

artic

ular

cas

es, s

uch

as a

line

ar c

hain

of e

lem

enta

ry

reac

tions

, no

equi

libria

and

onl

y on

e si

gnifi

cant

act

ivat

ion

barri

er, t

he ra

te e

quat

ion

is e

quiv

alen

t to

the

slow

est s

tep

of th

e re

actio

n.

16.1

Rat

e ex

pres

sion

and

reac

tion

mec

hani

sm

Nat

ure

of s

cien

ce:

Prin

cipl

e of

Occ

am’s

razo

r—ne

wer

theo

ries

need

to re

mai

n as

sim

ple

as p

ossi

ble

whi

le m

axim

izin

g ex

plan

ator

y po

wer

. The

low

pro

babi

lity

of th

ree

mol

ecul

e co

llisi

ons

mea

ns s

tepw

ise

reac

tion

mec

hani

sms

are

mor

e lik

ely.

(2.7

)

Und

erst

andi

ngs:

• R

eact

ions

may

occ

ur b

y m

ore

than

one

ste

p an

d th

e sl

owes

t ste

p de

term

ines

th

e ra

te o

f rea

ctio

n (ra

te d

eter

min

ing

step

/RD

S).

• Th

e m

olec

ular

ity o

f an

elem

enta

ry s

tep

is th

e nu

mbe

r of r

eact

ant p

artic

les

taki

ng p

art i

n th

at s

tep.

• Th

e or

der o

f a re

actio

n ca

n be

eith

er in

tege

r or f

ract

iona

l in

natu

re. T

he o

rder

of

a re

actio

n ca

n de

scrib

e, w

ith re

spec

t to

a re

acta

nt, t

he n

umbe

r of p

artic

les

taki

ng p

art i

n th

e ra

te-d

eter

min

ing

step

.

• R

ate

equa

tions

can

onl

y be

det

erm

ined

exp

erim

enta

lly.

• Th

e va

lue

of th

e ra

te c

onst

ant (

k) is

affe

cted

by

tem

pera

ture

and

its

units

are

de

term

ined

from

the

over

all o

rder

of t

he re

actio

n.

• C

atal

ysts

alte

r a re

actio

n m

echa

nism

, int

rodu

cing

a s

tep

with

low

er a

ctiv

atio

n en

ergy

.

App

licat

ions

and

ski

lls:

• D

educ

tion

of th

e ra

te e

xpre

ssio

n fo

r an

equa

tion

from

exp

erim

enta

l dat

a an

d so

lvin

g pr

oble

ms

invo

lvin

g th

e ra

te e

xpre

ssio

n.

• S

ketc

hing

, ide

ntify

ing,

and

ana

lysi

ng g

raph

ical

repr

esen

tatio

ns fo

r zer

o, fi

rst

and

seco

nd o

rder

reac

tions

.

• E

valu

atio

n of

pro

pose

d re

actio

n m

echa

nism

s to

be

cons

iste

nt w

ith k

inet

ic a

nd

stoi

chio

met

ric d

ata.

Inte

rnat

iona

l-min

dedn

ess:

• Th

e fir

st c

atal

yst u

sed

in in

dust

ry w

as fo

r the

pro

duct

ion

of s

ulfu

ric a

cid.

Sul

furic

ac

id p

rodu

ctio

n cl

osel

y m

irror

ed a

cou

ntry

’s e

cono

mic

hea

lth fo

r a lo

ng ti

me.

W

hat a

re s

ome

curre

nt in

dica

tors

of a

cou

ntry

’s e

cono

mic

hea

lth?

Theo

ry o

f kno

wle

dge:

• R

eact

ion

mec

hani

sm c

an b

e su

ppor

ted

by in

dire

ct e

vide

nce.

Wha

t is

the

role

of

empi

rical

evi

denc

e in

sci

entif

ic th

eorie

s? C

an w

e ev

er b

e ce

rtain

in s

cien

ce?

Util

izat

ion:

• C

ance

r res

earc

h is

all

abou

t ide

ntify

ing

mec

hani

sms;

for c

arci

noge

ns a

s w

ell a

s ca

ncer

-kill

ing

agen

ts a

nd in

hibi

tors

.

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 20

.1—

orga

nic

mec

hani

sms

espe

cial

ly S

N1

and

SN2

Opt

ion

A.3

—ca

taly

sts

Bio

logy

topi

c 8.

1—en

zym

es a

ctin

g as

cat

alys

ts

Aim

s:

• A

im 7

: Dat

abas

es, d

ata

logg

ers

and

othe

r IC

T ap

plic

atio

ns c

an b

e us

ed to

re

sear

ch p

ropo

sed

mec

hani

sms

for l

ab w

ork

perfo

rmed

and

to c

arry

out

virt

ual

expe

rimen

ts to

inve

stig

ate

fact

ors

whi

ch in

fluen

ce ra

te e

quat

ions

.

Topi

c 16

: Che

mic

al k

inet

ics

6 ho

urs

Add

ition

al h

ighe

r lev

el


Chemistry guide 87

16.1

Rat

e ex

pres

sion

and

reac

tion

mec

hani

sm

Gui

danc

e:

• C

alcu

latio

ns w

ill b

e lim

ited

to o

rder

s w

ith w

hole

num

ber v

alue

s.

• C

onsi

der c

once

ntra

tion

agai

nst t

ime

and

rate

aga

inst

con

cent

ratio

n gr

aphs

.

• U

se p

oten

tial e

nerg

y le

vel p

rofil

es to

illu

stra

te m

ulti-

step

reac

tions

; sho

win

g th

e hi

gher

Ea i

n th

e ra

te-d

eter

min

ing

step

in th

e pr

ofile

.

• C

atal

ysts

are

invo

lved

in th

e ra

te-d

eter

min

ing

step

.

• R

eact

ions

whe

re th

e ra

te-d

eter

min

ing

step

is n

ot th

e fir

st s

tep

shou

ld b

e co

nsid

ered

.

• A

ny e

xper

imen

t whi

ch a

llow

s st

uden

ts to

var

y co

ncen

tratio

ns to

see

the

effe

ct

upon

the

rate

and

hen

ce d

eter

min

e a

rate

equ

atio

n is

app

ropr

iate

.


Chemistry guide88

Esse

ntia

l ide

a: T

he a

ctiv

atio

n en

ergy

of a

reac

tion

can

be d

eter

min

ed fr

om th

e ef

fect

of t

empe

ratu

re o

n re

actio

n ra

te.

16.2

Act

ivat

ion

ener

gy

Nat

ure

of s

cien

ce:

Theo

ries

can

be s

uppo

rted

or fa

lsifi

ed a

nd re

plac

ed b

y ne

w th

eorie

s—ch

angi

ng th

e te

mpe

ratu

re o

f a re

actio

n ha

s a

muc

h gr

eate

r effe

ct o

n th

e ra

te o

f rea

ctio

n th

an c

an b

e ex

plai

ned

by it

s ef

fect

on

collis

ion

rate

s. T

his

resu

lted

in th

e de

velo

pmen

t of t

he A

rrhen

ius

equa

tion

whi

ch p

ropo

ses

a qu

antit

ativ

e m

odel

to e

xpla

in th

e ef

fect

of t

empe

ratu

re

chan

ge o

n re

actio

n ra

te. (

2.5)

Und

erst

andi

ngs:

• Th

e A

rrhen

ius

equa

tion

uses

the

tem

pera

ture

dep

ende

nce

of th

e ra

te c

onst

ant

to d

eter

min

e th

e ac

tivat

ion

ener

gy.

• A

gra

ph o

f 1/T

aga

inst

ln k

is a

line

ar p

lot w

ith g

radi

ent –

Ea /

R a

nd in

terc

ept,

lnA

.

• Th

e fre

quen

cy fa

ctor

(or p

re-e

xpon

entia

l fac

tor)

(A) t

akes

into

acc

ount

the

frequ

ency

of c

ollis

ions

with

pro

per o

rient

atio

ns.

App

licat

ions

and

ski

lls:

• A

naly

sing

gra

phic

al re

pres

enta

tion

of th

e A

rrhen

ius

equa

tion

in it

s lin

ear f

orm

lnk

= -E

aRT

+ln

A.

• U

sing

the

Arrh

eniu

s eq

uatio

n 𝑘𝑘

= 𝐴𝐴

𝑒𝑒−𝐸𝐸𝑎𝑎

𝑅𝑅𝑅𝑅.

• D

escr

ibin

g th

e re

latio

nshi

ps b

etw

een

tem

pera

ture

and

rate

con

stan

t; fre

quen

cy

fact

or a

nd c

ompl

exity

of m

olec

ules

col

lidin

g.

• D

eter

min

ing

and

eval

uatin

g va

lues

of a

ctiv

atio

n en

ergy

and

freq

uenc

y fa

ctor

s fro

m d

ata.

Gui

danc

e:

• U

se e

nerg

y le

vel d

iagr

ams

to il

lust

rate

mul

ti-st

ep re

actio

ns s

how

ing

the

RD

S in

th

e di

agra

m.

• C

onsi

der v

ario

us d

ata

sour

ces

in u

sing

the

linea

r exp

ress

ion

lnk

= -E

aRT

+ln

A.

The

expr

essi

on ln

𝑘𝑘 1 𝑘𝑘 2=

𝐸𝐸 𝑎𝑎 𝑅𝑅(1 𝑇𝑇 2

−1 𝑇𝑇 1

) is

give

n in

the

data

boo

klet

.

Util

izat

ion:

• Th

e fla

shin

g lig

ht o

f fire

flies

is p

rodu

ced

by a

che

mic

al p

roce

ss in

volv

ing

enzy

mes

.

• Th

e re

latio

nshi

p be

twee

n th

e “lo

ck a

nd k

ey” h

ypot

hesi

s of

enz

ymes

and

the

Arrh

eniu

s eq

uatio

n.

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 6.

1—co

llisi

on th

eory

Aim

s:

• A

ims

4 an

d 7:

Use

of s

imul

atio

ns a

nd v

irtua

l exp

erim

ents

to s

tudy

effe

ct o

f te

mpe

ratu

re a

nd s

teric

fact

ors

on ra

tes

of re

actio

n.

• A

im 6

: Exp

erim

ents

cou

ld in

clud

e th

ose

invo

lvin

g th

e co

llect

ion

of te

mpe

ratu

re

read

ings

to o

btai

n su

ffici

ent d

ata

for a

gra

ph.

• A

im 7

: Gra

phin

g ca

lcul

ator

s ca

n be

em

ploy

ed to

eas

ily in

put a

nd a

naly

se d

ata

for E

a and

freq

uenc

y fa

ctor

val

ues.



Topi

c 17

: Equ

ilibr

ium

4

hour

s

Add

ition

al h

ighe

r lev

el

Esse

ntia

l ide

a: T

he p

ositi

on o

f equ

ilibr

ium

can

be

quan

tifie

d by

the

equi

libriu

m la

w. T

he e

quili

briu

m c

onst

ant f

or a

par

ticul

ar re

actio

n on

ly d

epen

ds o

n th

e te

mpe

ratu

re.

17.1

The

equ

ilibr

ium

law

Nat

ure

of s

cien

ce:

Em

ploy

ing

quan

titat

ive

reas

onin

g—ex

perim

enta

lly d

eter

min

ed ra

te e

xpre

ssio

ns fo

r for

war

d an

d ba

ckw

ard

reac

tions

can

be

dedu

ced

dire

ctly

from

the

stoi

chio

met

ric

equa

tions

and

allo

w L

e C

hâte

lier’s

prin

cipl

e to

be

appl

ied.

(1.8

, 1.9

)

Und

erst

andi

ngs:

• Le

Châ

telie

r’s p

rinci

ple

for c

hang

es in

con

cent

ratio

n ca

n be

exp

lain

ed b

y th

e eq

uilib

rium

law

.

• Th

e po

sitio

n of

equ

ilibr

ium

cor

resp

onds

to a

max

imum

val

ue o

f ent

ropy

and

a

min

imum

in th

e va

lue

of th

e G

ibbs

free

ene

rgy.

• Th

e G

ibbs

free

ene

rgy

chan

ge o

f a re

actio

n an

d th

e eq

uilib

rium

con

stan

t can

bo

th b

e us

ed to

mea

sure

the

posi

tion

of a

n eq

uilib

rium

reac

tion

and

are

rela

ted

by th

e eq

uatio

n, ∆

Gᴏ=

-RT

lnK

.

App

licat

ions

and

ski

lls:

• S

olut

ion

of h

omog

eneo

us e

quili

briu

m p

robl

ems

usin

g th

e ex

pres

sion

for K

c.

• R

elat

ions

hip

betw

een

∆Gᴏ

and

the

equi

libriu

m c

onst

ant.

• C

alcu

latio

ns u

sing

the

equa

tion

∆Gᴏ

= −

𝑅𝑅𝑅𝑅 ln

𝐾𝐾.

Gui

danc

e:

• Th

e ex

pres

sion

∆Gᴏ

= −

𝑅𝑅𝑅𝑅 ln

𝐾𝐾 is

giv

en in

the

data

boo

klet

in s

ectio

n 1.

• S

tude

nts

will

not

be

expe

cted

to d

eriv

e th

e ex

pres

sion

∆Gᴏ

= −

𝑅𝑅𝑅𝑅 ln

𝐾𝐾.

• Th

e us

e of

qua

drat

ic e

quat

ions

will

not

be

asse

ssed

.

Theo

ry o

f kno

wle

dge:

• Th

e eq

uilib

rium

law

can

be

dedu

ced

by a

ssum

ing

that

the

orde

r of t

he fo

rwar

d an

d ba

ckw

ard

reac

tion

mat

ches

the

coef

ficie

nts

in th

e ch

emic

al e

quat

ion.

Wha

t is

the

role

of d

educ

tive

reas

onin

g in

sci

ence

?

• W

e ca

n us

e m

athe

mat

ics

succ

essf

ully

to m

odel

equ

ilibr

ium

sys

tem

s. Is

this

be

caus

e w

e cr

eate

mat

hem

atic

s to

mirr

or re

ality

or b

ecau

se th

e re

ality

is

intri

nsic

ally

mat

hem

atic

al?

• M

any

prob

lem

s in

sci

ence

can

onl

y be

sol

ved

whe

n as

sum

ptio

ns a

re m

ade

whi

ch s

impl

ify th

e m

athe

mat

ics.

Wha

t is

the

role

of i

ntui

tion

in p

robl

em s

olvi

ng?

Util

izat

ion:

• Th

e co

ncep

t of a

clo

sed

syst

em in

dyn

amic

equ

ilibr

ium

can

be

appl

ied

to a

ra

nge

of s

yste

ms

in th

e bi

olog

ical

, env

ironm

enta

l and

hum

an s

cien

ces.

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 1.

3—st

oich

iom

etric

equ

atio

ns

Topi

c 7.

1—eq

uilib

rium

To

pic

18.2

—w

eak

acid

and

bas

e eq

uilib

ria

Opt

ion

A.1

0—K

sp

Opt

ions

B.7

and

D.4

—bu

ffer c

alcu

latio

ns


Chemistry guide90

17.1

The

equ

ilibr

ium

law

Aim

s:

• A

im 6

: The

equ

ilibr

ium

con

stan

t for

an

este

rific

atio

n re

actio

n an

d ot

her

reac

tions

cou

ld b

e ex

perim

enta

lly in

vest

igat

ed.

• A

im 7

: The

con

cept

of a

dyn

amic

equ

ilibr

ium

can

be

illus

trate

d w

ith c

ompu

ter

anim

atio

ns.



Add

ition

al h

ighe

r lev

el

Topi

c 18

: Aci

ds a

nd b

ases

10

hou

rs

Esse

ntia

l ide

a: T

he a

cid–

base

con

cept

can

be

exte

nded

to re

actio

ns th

at d

o no

t inv

olve

pro

ton

trans

fer.

18.1

Lew

is a

cids

and

bas

es

Nat

ure

of s

cien

ce:

Theo

ries

can

be s

uppo

rted,

fals

ified

or r

epla

ced

by n

ew th

eorie

s—ac

id–b

ase

theo

ries

can

be e

xten

ded

to a

wid

er fi

eld

of a

pplic

atio

ns b

y co

nsid

erin

g lo

ne p

airs

of e

lect

rons

. Le

wis

theo

ry d

oesn

't fa

lsify

Brø

nste

d–Lo

wry

but

ext

ends

it. (

2.5)

Und

erst

andi

ngs:

• A

Lew

is a

cid

is a

lone

pai

r acc

epto

r and

a L

ewis

bas

e is

a lo

ne p

air d

onor

.

• W

hen

a Le

wis

bas

e re

acts

with

a L

ewis

aci

d a

coor

dina

te b

ond

is fo

rmed

.

• A

nuc

leop

hile

is a

Lew

is b

ase

and

an e

lect

roph

ile is

a L

ewis

aci

d.

App

licat

ions

and

ski

lls:

• A

pplic

atio

n of

Lew

is’ a

cid–

base

theo

ry to

inor

gani

c an

d or

gani

c ch

emis

try to

id

entif

y th

e ro

le o

f the

reac

ting

spec

ies.

Gui

danc

e:

• B

oth

orga

nic

and

inor

gani

c ex

ampl

es s

houl

d be

stu

died

.

• R

elat

ions

bet

wee

n B

røns

ted–

Low

ry a

nd L

ewis

aci

ds a

nd b

ases

sho

uld

be

disc

usse

d.

Inte

rnat

iona

l-min

dedn

ess:

• A

cid–

base

theo

ry h

as d

evel

oped

from

the

idea

s of

peo

ple

from

diff

eren

t par

ts

of th

e w

orld

thro

ugh

both

col

labo

ratio

n an

d co

mpe

titio

n.

Theo

ry o

f kno

wle

dge:

• Th

e sa

me

phen

omen

on c

an s

omet

imes

be

expl

ored

from

diff

eren

t pe

rspe

ctiv

es, a

nd e

xpla

ined

by

diffe

rent

theo

ries.

For

exa

mpl

e, d

o w

e ju

dge

com

petin

g th

eorie

s by

thei

r uni

vers

ality

, sim

plic

ity o

r ele

ganc

e?

Util

izat

ion:

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

cs 4

.2 a

nd 4

.3—

cova

lent

mol

ecul

es a

nd L

ewis

dot

dia

gram

s

Topi

c 13

.2—

trans

ition

met

al c

ompl

exes

To

pic

20.1

—nu

cleo

phile

s

Aim

s:

• A

im 6

: Tra

nsiti

on m

etal

com

plex

es c

ould

be

expe

rimen

tally

exp

lore

d.

• A

im 7

: Ani

mat

ions

can

be

used

to d

istin

guis

h be

twee

n th

e di

ffere

nt a

cid–

base

th

eorie

s.


Chemistry guide92

Esse

ntia

l ide

a: T

he e

quili

briu

m la

w c

an b

e ap

plie

d to

aci

d–ba

se re

actio

ns. N

umer

ical

pro

blem

s ca

n be

sim

plifi

ed b

y m

akin

g as

sum

ptio

ns a

bout

the

rela

tive

conc

entra

tions

of

the

spec

ies

invo

lved

. The

use

of l

ogar

ithm

s is

als

o si

gnifi

cant

her

e.

18.2

Cal

cula

tions

invo

lvin

g ac

ids

and

base

s

Nat

ure

of s

cien

ce:

Obt

aini

ng e

vide

nce

for s

cien

tific

theo

ries—

appl

icat

ion

of th

e eq

uilib

rium

law

allo

ws

stre

ngth

s of

aci

ds a

nd b

ases

to b

e de

term

ined

and

rela

ted

to th

eir m

olec

ular

stru

ctur

e.

(1.9

)

Und

erst

andi

ngs:

• Th

e ex

pres

sion

for t

he d

isso

ciat

ion

cons

tant

of a

wea

k ac

id (K

a) a

nd a

wea

k ba

se (K

b).

• Fo

r a c

onju

gate

aci

d ba

se p

air,

Ka ×

Kb =

Kw.

• Th

e re

latio

nshi

p be

twee

n K

a an

d pK

a is

(pK

a = -l

og K

a), a

nd b

etw

een

Kb an

d pK

b is

(pK

b = -l

og K

b).

App

licat

ions

and

ski

lls:

• S

olut

ion

of p

robl

ems

invo

lvin

g [H

+ (aq

)], [O

H– (

aq)],

pH

, pO

H, K

a, pK

a, K

b an

d pK

b.

• D

iscu

ssio

n of

the

rela

tive

stre

ngth

s of

aci

ds a

nd b

ases

usi

ng v

alue

s of

Ka,

pKa,

Kb a

nd p

Kb.

Gui

danc

e:

• Th

e va

lue

Kw d

epen

ds o

n th

e te

mpe

ratu

re.

• Th

e ca

lcul

atio

n of

pH

in b

uffe

r sol

utio

ns w

ill o

nly

be a

sses

sed

in o

ptio

ns B

.7

and

D.4

.

• O

nly

exam

ples

invo

lvin

g th

e tra

nsfe

r of o

ne p

roto

n w

ill b

e as

sess

ed.

• C

alcu

latio

ns o

f pH

at t

empe

ratu

res

othe

r tha

n 29

8 K

can

be

asse

ssed

.

• S

tude

nts

shou

ld s

tate

whe

n ap

prox

imat

ions

are

use

d in

equ

ilibr

ium

ca

lcul

atio

ns.

• Th

e us

e of

qua

drat

ic e

quat

ions

will

not

be

asse

ssed

.

Inte

rnat

iona

l-min

dedn

ess:

• M

athe

mat

ics

is a

uni

vers

al la

ngua

ge. T

he m

athe

mat

ical

nat

ure

of th

is to

pic

help

s ch

emis

ts s

peak

ing

diffe

rent

nat

ive

lang

uage

s to

com

mun

icat

e m

ore

obje

ctiv

ely.

Util

izat

ion:

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 8.

1—co

njug

ate

acid

–bas

e pa

irs

Topi

c 8.

3—th

e pH

con

cept

To

pic

8.4—

stro

ng a

nd w

eak

acid

s an

d ba

ses

Opt

ions

B.7

and

D.4

—bu

ffers

Aim

s:

• A

im 6

: The

pro

perti

es o

f stro

ng a

nd w

eak

acid

s co

uld

be in

vest

igat

ed

expe

rimen

tally

.


Chemistry guide 93

Esse

ntia

l ide

a: p

H c

urve

s ca

n be

inve

stig

ated

exp

erim

enta

lly b

ut a

re m

athe

mat

ical

ly d

eter

min

ed b

y th

e di

ssoc

iatio

n co

nsta

nts

of th

e ac

id a

nd b

ase.

An

indi

cato

r w

ith a

n ap

prop

riate

end

poi

nt c

an b

e us

ed to

det

erm

ine

the

equi

vale

nce

poin

t of t

he re

actio

n.

18.3

pH

cur

ves

Nat

ure

of s

cien

ce:

Incr

ease

d po

wer

of i

nstru

men

tatio

n an

d ad

vanc

es in

ava

ilabl

e te

chni

ques

—de

velo

pmen

t in

pH m

eter

tech

nolo

gy h

as a

llow

ed fo

r mor

e re

liabl

e an

d re

ady

mea

sure

men

t of

pH. (

3.7)

Und

erst

andi

ngs:

• Th

e ch

arac

teris

tics

of th

e pH

cur

ves

prod

uced

by

the

diffe

rent

com

bina

tions

of

stro

ng a

nd w

eak

acid

s an

d ba

ses.

• A

n ac

id–b

ase

indi

cato

r is

a w

eak

acid

or a

wea

k ba

se w

here

the

com

pone

nts

of

the

conj

ugat

e ac

id–b

ase

pair

have

diff

eren

t col

ours

.

• Th

e re

latio

nshi

p be

twee

n th

e pH

rang

e of

an

acid

–bas

e in

dica

tor,

whi

ch is

a

wea

k ac

id, a

nd it

s pK

a val

ue.

• Th

e bu

ffer r

egio

n on

the

pH c

urve

repr

esen

ts th

e re

gion

whe

re s

mal

l add

ition

s of

aci

d or

bas

e re

sult

in li

ttle

or n

o ch

ange

in p

H.

• Th

e co

mpo

sitio

n an

d ac

tion

of a

buf

fer s

olut

ion.

App

licat

ions

and

ski

lls:

• Th

e ge

nera

l sha

pes

of g

raph

s of

pH

aga

inst

vol

ume

for t

itrat

ions

invo

lvin

g st

rong

and

wea

k ac

ids

and

base

s w

ith a

n ex

plan

atio

n of

thei

r im

porta

nt

feat

ures

.

• S

elec

tion

of a

n ap

prop

riate

indi

cato

r for

a ti

tratio

n, g

iven

the

equi

vale

nce

poin

t of

the

titra

tion

and

the

end

poin

t of t

he in

dica

tor.

• W

hile

the

natu

re o

f the

aci

d–ba

se b

uffe

r alw

ays

rem

ains

the

sam

e, b

uffe

r so

lutio

ns c

an b

e pr

epar

ed b

y ei

ther

mix

ing

a w

eak

acid

/bas

e w

ith a

sol

utio

n of

a

salt

cont

aini

ng it

s co

njug

ate,

or b

y pa

rtial

neu

traliz

atio

n of

a w

eak

acid

/bas

e w

ith a

stro

ng a

cid/

base

.

• P

redi

ctio

n of

the

rela

tive

pH o

f aqu

eous

sal

t sol

utio

ns fo

rmed

by

the

diffe

rent

co

mbi

natio

ns o

f stro

ng a

nd w

eak

acid

and

bas

e.

Theo

ry o

f kno

wle

dge:

• Is

a p

H c

urve

an

accu

rate

des

crip

tion

of re

ality

or a

n ar

tific

ial r

epre

sent

atio

n?

Doe

s sc

ienc

e of

fer a

repr

esen

tatio

n of

real

ity?

Util

izat

ion:

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 5.

1—th

erm

omet

ric/c

ondu

ctio

met

ric ti

tratio

ns

Topi

c 16

.2—

Wha

t are

the

unus

ual m

athe

mat

ical

feat

ures

of a

pH

cur

ve?

Stu

dent

s sh

ould

als

o be

fam

iliar

with

the

use

of n

atur

al lo

gs w

hen

usin

g th

e A

rrhen

ius

expr

essi

on in

topi

c 16

.2

Aim

s:

• A

im 6

: Exp

erim

ents

cou

ld in

clud

e in

vest

igat

ion

of p

H c

urve

s, d

eter

min

atio

n of

th

e pK

a of a

wea

k ac

id, p

repa

ratio

n an

d in

vest

igat

ion

of a

buf

fer s

olut

ion

and

the

dete

rmin

atio

n of

the

pKa o

f an

indi

cato

r.

• A

im 7

: Dat

a lo

ggin

g, d

atab

ases

, spr

eads

heet

s an

d si

mul

atio

ns c

an a

ll be

use

d.

For e

xam

ple,

the

equi

vale

nce

poin

t cou

ld b

e de

term

ined

by

usin

g a

cond

uctiv

ity

prob

e or

a te

mpe

ratu

re p

robe

.


Chemistry guide94

18.3

pH

cur

ves

Gui

danc

e:

• O

nly

exam

ples

invo

lvin

g th

e tra

nsfe

r of o

ne p

roto

n w

ill b

e as

sess

ed. I

mpo

rtant

fe

atur

es a

re:

– in

terc

ept w

ith p

H a

xis

– eq

uiva

lenc

e po

int

– bu

ffer r

egio

n

– po

ints

whe

re p

Ka =

pH

or p

Kb =

pO

H.

• Fo

r an

indi

cato

r whi

ch is

a w

eak

acid

:

– H

In(a

q)

H+ (

aq) +

In- (a

q)

Col

our A

Col

our B

– Th

e co

lour

cha

nge

can

be c

onsi

dere

d to

tak

e pl

ace

over

a r

ange

of

pKa ±

1.

• Fo

r an

indi

cato

r whi

ch is

a w

eak

base

:

B+(a

q) +

OH- (a

q)

– B

OH

(aq)

Col

our A

C

olou

r B

• E

xam

ples

of i

ndic

ator

s ar

e lis

ted

in th

e da

ta b

ookl

et in

sec

tion

22.

• S

alts

form

ed fr

om th

e fo

ur p

ossi

ble

com

bina

tions

of s

trong

and

wea

k ac

ids

and

base

s sh

ould

be

cons

ider

ed. C

alcu

latio

ns a

re n

ot re

quire

d.



Add

ition

al h

ighe

r lev

el

Topi

c 19

: Red

ox p

roce

sses

6

hour

s

Esse

ntia

l ide

a: E

nerg

y co

nver

sions

bet

wee

n el

ectr

ical

and

che

mic

al e

nerg

y lie

at t

he c

ore

of e

lect

roch

emic

al c

ells.

19

.1 E

lect

roch

emic

al c

ells

Nat

ure

of s

cien

ce:

Em

ploy

ing

quan

titat

ive

reas

onin

g—el

ectro

de p

oten

tials

and

the

stan

dard

hyd

roge

n el

ectro

de. (

3.1)

Col

labo

ratio

n an

d et

hica

l im

plic

atio

ns—

scie

ntis

ts h

ave

colla

bora

ted

to w

ork

on e

lect

roch

emic

al c

ell t

echn

olog

ies

and

have

to c

onsi

der t

he e

nviro

nmen

tal a

nd e

thic

al

impl

icat

ions

of u

sing

fuel

cel

ls a

nd m

icro

bial

fuel

cel

ls. (

4.5)

Und

erst

andi

ngs:

• A

vol

taic

cel

l gen

erat

es a

n el

ectro

mot

ive

forc

e (E

MF)

resu

lting

in th

e m

ovem

ent

of e

lect

rons

from

the

anod

e (n

egat

ive

elec

trode

) to

the

cath

ode

(pos

itive

el

ectro

de) v

ia th

e ex

tern

al c

ircui

t. Th

e E

MF

is te

rmed

the

cell

pote

ntia

l (E

º).

• Th

e st

anda

rd h

ydro

gen

elec

trode

(SH

E) c

onsi

sts

of a

n in

ert p

latin

um e

lect

rode

in

con

tact

with

1 m

ol d

m-3

hyd

roge

n io

n an

d hy

drog

en g

as a

t 100

kP

a an

d 29

8 K

. The

sta

ndar

d el

ectro

de p

oten

tial (

Eº)

is th

e po

tent

ial (

volta

ge) o

f the

re

duct

ion

half-

equa

tion

unde

r sta

ndar

d co

nditi

ons

mea

sure

d re

lativ

e to

the

SH

E. S

olut

e co

ncen

tratio

n is

1 m

ol d

m-3

or 1

00 k

Pa

for g

ases

. Eº o

f the

SH

E is

0

V.

• W

hen

aque

ous

solu

tions

are

ele

ctro

lyse

d, w

ater

can

be

oxid

ized

to o

xyge

n at

th

e an

ode

and

redu

ced

to h

ydro

gen

at th

e ca

thod

e.

• ∆𝐺𝐺

°=

−𝑛𝑛𝑛𝑛

𝑛𝑛° .Whe

n E

º is

posi

tive,

G

º is n

egat

ive

indi

cativ

e of

a s

pont

aneo

us

proc

ess.

Whe

n E

º is

nega

tive,

G

º is p

ositi

ve in

dica

tive

of a

non

-spo

ntan

eous

pr

oces

s. W

hen

Eº i

s 0,

then

G

º is 0

.

• C

urre

nt, d

urat

ion

of e

lect

roly

sis

and

char

ge o

n th

e io

n af

fect

the

amou

nt o

f pr

oduc

t for

med

at t

he e

lect

rode

s du

ring

elec

troly

sis.

• El

ectro

plat

ing

invo

lves

the

elec

troly

tic c

oatin

g of

an

obje

ct w

ith a

met

allic

thin

laye

r.

Inte

rnat

iona

l-min

dedn

ess:

• M

any

elec

troch

emic

al c

ells

can

act

as

ener

gy s

ourc

es a

llevi

atin

g th

e w

orld

’s

ener

gy p

robl

ems

but s

ome

cells

suc

h as

sup

er-e

ffici

ent m

icro

bial

fuel

cel

ls

(MFC

s) (a

lso

term

ed b

iolo

gica

l fue

l cel

ls) c

an c

ontri

bute

to c

lean

-up

of th

e en

viro

nmen

t. H

ow d

o na

tiona

l gov

ernm

ents

and

the

inte

rnat

iona

l com

mun

ity

deci

de o

n re

sear

ch p

riorit

ies

for f

undi

ng p

urpo

ses?

Theo

ry o

f kno

wle

dge:

• Th

e S

HE

is a

n ex

ampl

e of

an

arbi

trary

refe

renc

e. W

ould

our

sci

entif

ic

know

ledg

e be

the

sam

e if

we

chos

e di

ffere

nt re

fere

nces

?

Util

izat

ion:

• E

lect

ropl

atin

g.

• E

lect

roch

emic

al p

roce

sses

in d

entis

try.

• R

ustin

g of

met

als.

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

cs 1

.2 a

nd 1

.3—

prob

lem

s in

volv

ing

Avo

gadr

o’s

cons

tant

, am

ount

of s

ubst

ance

an

d th

e id

eal g

as e

quat

ion

Topi

c 9.

1—re

dox

proc

esse

s


Chemistry guide96

19.1

Ele

ctro

chem

ical

cel

ls

App

licat

ions

and

ski

lls:

• C

alcu

latio

n of

cel

l pot

entia

ls u

sing

sta

ndar

d el

ectro

de p

oten

tials

.

• P

redi

ctio

n of

whe

ther

a re

actio

n is

spo

ntan

eous

or n

ot u

sing

Eo v

alue

s.

• D

eter

min

atio

n of

sta

ndar

d fre

e-en

ergy

cha

nges

(G

o ) u

sing

sta

ndar

d el

ectro

de

pote

ntia

ls.

• Ex

plan

atio

n of

the

prod

ucts

form

ed d

urin

g th

e el

ectro

lysis

of a

queo

us s

olut

ions

.

• P

erfo

rm la

b ex

perim

ents

that

cou

ld in

clud

e si

ngle

repl

acem

ent r

eact

ions

in

aque

ous

solu

tions

.

• D

eter

min

atio

n of

the

rela

tive

amou

nts

of p

rodu

cts

form

ed d

urin

g el

ectro

lytic

pr

oces

ses.

• E

xpla

natio

n of

the

proc

ess

of e

lect

ropl

atin

g.

Gui

danc

e:

• E

lect

roly

tic p

roce

sses

to b

e co

vere

d in

theo

ry s

houl

d in

clud

e th

e el

ectro

lysi

s of

aq

ueou

s so

lutio

ns (e

g so

dium

chl

orid

e, c

oppe

r(II)

sulfa

te e

tc) a

nd w

ater

usi

ng

both

iner

t pla

tinum

or g

raph

ite e

lect

rode

s an

d co

pper

ele

ctro

des.

Exp

lana

tions

sh

ould

refe

r to

Eº v

alue

s, n

atur

e of

the

elec

trode

and

con

cent

ratio

n of

the

elec

troly

te.

• ∆𝐺𝐺

°=

−𝑛𝑛𝑛𝑛

𝑛𝑛° is

give

n in

the

data

boo

klet

in s

ectio

n 1.

• Fa

rada

y’s

cons

tant

= 9

6 50

0 C

mol

-1 is

giv

en in

the

data

boo

klet

in s

ectio

n 2.

• Th

e te

rm “c

ells

in s

erie

s” s

houl

d be

und

erst

ood.

Topi

c 15

.2—

spon

tane

ity o

f a re

actio

n O

ptio

n C

.6—

Ner

nst e

quat

ion

Bio

logy

opt

ion

B.3

—en

viro

nmen

tal p

rote

ctio

n; w

aste

trea

tmen

t and

mic

robi

al fu

el

cells

Aim

s:

• A

im 8

: Bio

logi

cal f

uel c

ells

can

pro

duce

ele

ctric

al e

nerg

y to

pow

er e

lect

rical

de

vice

s, h

ouse

s, fa

ctor

ies

etc.

The

y ca

n as

sist

in e

nviro

nmen

tal c

lean

-up.

M

icro

bial

fuel

cel

ls (M

FCs)

pow

ered

by

mic

robe

s in

sew

age

can

clea

n up

se

wag

e w

hich

may

resu

lt in

cos

t-fre

e w

aste

wat

er tr

eatm

ent.



Add

ition

al h

ighe

r lev

el

Topi

c 20

: Org

anic

che

mis

try

12 h

ours

Topic 20 – Organic chemistry

Chemistry guide98

20.1

Typ

es o

f org

anic

reac

tions

• M

arko

vnik

ov’s

rule

can

be

appl

ied

to p

redi

ct th

e m

ajor

pro

duct

in

elec

troph

ilic

addi

tion

reac

tions

of u

nsym

met

rical

alk

enes

with

hyd

roge

n ha

lides

and

inte

rhal

ogen

s. T

he fo

rmat

ion

of th

e m

ajor

pro

duct

can

be

expl

aine

d in

term

s of

the

rela

tive

stab

ility

of p

ossi

ble

carb

ocat

ions

in th

e re

actio

n m

echa

nism

.

Ele

ctro

phili

c S

ubst

itutio

n R

eact

ions

:

• Be

nzen

e is

the

sim

ples

t aro

mat

ic h

ydro

carb

on c

ompo

und

(or a

rene

) and

has

a

delo

caliz

ed s

truct

ure

of

bon

ds a

roun

d its

ring

. Eac

h ca

rbon

to c

arbo

n bo

nd

has

a bo

nd o

rder

of 1

.5. B

enze

ne is

sus

cept

ible

to a

ttack

by

elec

troph

iles.

Red

uctio

n R

eact

ions

:

• C

arbo

xylic

aci

ds c

an b

e re

duce

d to

prim

ary

alco

hols

(via

the

alde

hyde

). K

eton

es c

an b

e re

duce

d to

sec

onda

ry a

lcoh

ols.

Typ

ical

redu

cing

age

nts

are

lithi

um a

lum

iniu

m h

ydrid

e (u

sed

to re

duce

car

boxy

lic a

cids

) and

sod

ium

bo

rohy

drid

e.

App

licat

ions

and

ski

lls:

Nuc

leop

hilic

Sub

stitu

tion

Rea

ctio

ns:

• E

xpla

natio

n of

why

hyd

roxi

de is

a b

ette

r nuc

leop

hile

than

wat

er.

• D

educ

tion

of th

e m

echa

nism

of t

he n

ucle

ophi

lic s

ubst

itutio

n re

actio

ns o

f ha

loge

noal

kane

s w

ith a

queo

us s

odiu

m h

ydro

xide

in te

rms

of S

N1

and

SN2

mec

hani

sms.

Exp

lana

tion

of h

ow th

e ra

te d

epen

ds o

n th

e id

entit

y of

the

halo

gen

(ie th

e le

avin

g gr

oup)

, whe

ther

the

halo

geno

alka

ne is

prim

ary,

se

cond

ary

or te

rtiar

y an

d th

e ch

oice

of s

olve

nt.

• O

utlin

e of

the

diffe

renc

e be

twee

n pr

otic

and

apr

otic

sol

vent

s.

Ele

ctro

phili

c A

dditi

on R

eact

ions

:

• D

educ

tion

of th

e m

echa

nism

of t

he e

lect

roph

ilic

addi

tion

reac

tions

of a

lken

es

with

hal

ogen

s/in

terh

alog

ens

and

hydr

ogen

hal

ides

.

• A

im 6

: A ra

nge

of e

xper

imen

ts o

f org

anic

syn

thet

ic re

actio

ns e

xplo

ring

vario

us

type

s of

reac

tions

and

func

tiona

l gro

up in

terc

onve

rsio

ns c

ould

be

done

. Cor

e te

chni

ques

of o

rgan

ic c

hem

istry

cou

ld in

clud

e re

flux,

dis

tilla

tion,

filtr

atio

n,

purif

icat

ion

(incl

udin

g ch

rom

atog

raph

ic te

chni

ques

), se

para

tions

and

ext

ract

ions

.

• A

im 6

: Syn

thes

is (o

r rea

ctio

n) in

the

labo

rato

ry o

f an

exam

ple

of a

wid

ely

used

dr

ug o

r med

icin

e (e

g as

pirin

) or a

hou

seho

ld p

rodu

ct (e

g fa

ding

of t

omat

o ke

tchu

p—el

ectro

phili

c ad

ditio

n re

actio

n of

bro

min

e).


Chemistry guide 99

20.1

Typ

es o

f org

anic

reac

tions

Ele

ctro

phili

c S

ubst

itutio

n R

eact

ions

:

• D

educ

tion

of th

e m

echa

nism

of t

he n

itrat

ion

(ele

ctro

phili

c su

bstit

utio

n)

reac

tion

of b

enze

ne (u

sing

a m

ixtu

re o

f con

cent

rate

d ni

tric

acid

and

sul

furic

ac

id).

Red

uctio

n R

eact

ions

:

• W

ritin

g re

duct

ion

reac

tions

of c

arbo

nyl c

onta

inin

g co

mpo

unds

: ald

ehyd

es

and

keto

nes

to p

rimar

y an

d se

cond

ary

alco

hols

and

car

boxy

lic a

cids

to

alco

hols

, usi

ng s

uita

ble

redu

cing

age

nts.

• C

onve

rsio

n of

nitr

oben

zene

to p

heny

lam

ine

via

a tw

o-st

age

reac

tion.

Gui

danc

e:

• R

efer

ence

sho

uld

be m

ade

to h

eter

olyt

ic fi

ssio

n fo

r SN1

reac

tions

.

• Th

e di

ffere

nce

betw

een

hom

olyt

ic a

nd h

eter

olyt

ic fi

ssio

n sh

ould

be

unde

rsto

od.

• Th

e di

ffere

nce

betw

een

curly

arro

ws

and

fish-

hook

s in

reac

tion

mec

hani

sms

shou

ld b

e em

phas

ized

.

• U

se o

f par

tial c

harg

es (

+ an

d -

) and

wed

ge-d

ash

thre

e-di

men

sion

al

repr

esen

tatio

ns (u

sing

tape

red

bond

s as

sho

wn

belo

w) s

houl

d be

en

cour

aged

whe

re a

ppro

pria

te in

exp

lain

ing

reac

tion

mec

hani

sms.

• Ty

pica

l con

ditio

ns a

nd re

agen

ts o

f all

reac

tions

sho

uld

be k

now

n (e

g ca

taly

sts,

redu

cing

age

nts,

reflu

x et

c.).

How

ever

, mor

e pr

ecis

e de

tails

suc

h as

spe

cific

tem

pera

ture

s ne

ed n

ot b

e in

clud

ed.


Chemistry guide100

Esse

ntia

l ide

a: O

rgan

ic s

ynth

esis

is th

e sy

stem

atic

pre

para

tion

of a

com

poun

d fro

m a

wid

ely

avai

labl

e st

artin

g m

ater

ial o

r the

syn

thes

is o

f a c

ompo

und

via

a sy

nthe

tic ro

ute

that

ofte

n ca

n in

volv

e a

serie

s of

diff

eren

t ste

ps.

20.2

Syn

thet

ic ro

utes

Nat

ure

of s

cien

ce:

Sci

entif

ic m

etho

d—in

syn

thet

ic d

esig

n, th

e th

inki

ng p

roce

ss o

f the

org

anic

che

mis

t is

one

whi

ch in

voke

s re

tro-s

ynth

esis

and

the

abili

ty to

thin

k in

a re

vers

e-lik

e m

anne

r. (1

.3)

Und

erst

andi

ngs:

• Th

e sy

nthe

sis

of a

n or

gani

c co

mpo

und

stem

s fro

m a

read

ily a

vaila

ble

star

ting

mat

eria

l via

a s

erie

s of

dis

cret

e st

eps.

Fun

ctio

nal g

roup

inte

rcon

vers

ions

are

th

e ba

sis

of s

uch

synt

hetic

rout

es.

• R

etro

-syn

thes

is o

f org

anic

com

poun

ds.

App

licat

ions

and

ski

lls:

• D

educ

tion

of m

ulti-

step

syn

thet

ic ro

utes

giv

en s

tarti

ng re

agen

ts a

nd th

e pr

oduc

t(s).

Gui

danc

e:

• C

onve

rsio

ns w

ith m

ore

than

four

sta

ges

will

not

be

asse

ssed

in s

ynth

etic

ro

utes

.

• R

eact

ion

type

s ca

n co

ver a

ny o

f the

reac

tions

cov

ered

in to

pic

10 a

nd s

ub-to

pic

20.1

.

Inte

rnat

iona

l-min

dedn

ess:

• H

ow im

porta

nt a

re n

atur

al p

rodu

cts

to d

evel

opin

g co

untri

es?

Exp

lore

som

e sp

ecifi

c ex

ampl

es o

f nat

ural

pro

duct

s av

aila

ble

in d

evel

opin

g co

untri

es w

hich

ar

e im

porta

nt to

the

deve

lope

d w

orld

.

Theo

ry o

f kno

wle

dge:

• A

retro

-syn

thet

ic a

ppro

ach

is o

ften

used

in th

e de

sign

of s

ynth

etic

rout

es. W

hat

are

the

role

s of

imag

inat

ion,

intu

ition

and

reas

onin

g in

find

ing

solu

tions

to

prac

tical

pro

blem

s?

Util

izat

ion:

• N

atur

al p

rodu

cts

are

com

poun

ds is

olat

ed fr

om n

atur

al s

ourc

es a

nd in

clud

e ta

xol,

mes

calin

e an

d ca

psai

cin.

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

cs 1

0.1

and

10.2

—or

gani

c ch

emis

try

Aim

s:

• A

im 6

: Mul

tiple

sta

ge o

rgan

ic s

ynth

etic

rout

e se

ries

of e

xper

imen

ts (u

p to

a

max

imum

of f

our s

tage

s).


Chemistry guide 101

Ess

entia

l ide

a: S

tere

oiso

mer

ism

invo

lves

isom

ers

whi

ch h

ave

diffe

rent

arr

ange

men

ts o

f ato

ms

in s

pace

but

do

not d

iffer

in c

onne

ctiv

ity o

r bon

d m

ultip

licity

(ie

whe

ther

sin

gle,

do

uble

or t

riple

) bet

wee

n th

e is

omer

s th

emse

lves

.

20.3

Ste

reoi

som

eris

m

Nat

ure

of s

cien

ce:

Tran

sdis

cipl

inar

y—th

e th

ree-

dim

ensi

onal

sha

pe o

f an

orga

nic

mol

ecul

e is

the

foun

datio

n pi

llar o

f its

stru

ctur

e an

d of

ten

its p

rope

rties

. Muc

h of

the

hum

an b

ody

is c

hira

l. (4

.1)

Und

erst

andi

ngs:

• S

tere

oiso

mer

s ar

e su

bdiv

ided

into

two

clas

ses—

conf

orm

atio

nal i

som

ers,

whi

ch

inte

rcon

vert

by ro

tatio

n ab

out a

σ b

ond

and

conf

igur

atio

nal i

som

ers

that

in

terc

onve

rt on

ly b

y br

eaki

ng a

nd re

form

ing

a bo

nd.

Con

figur

atio

nal i

som

ers

are

furth

er s

ubdi

vide

d in

to c

is-tr

ans

and

E/Z

isom

ers

and

optic

al is

omer

s.

Inte

rnat

iona

l-min

dedn

ess:

• H

ave

drug

s an

d m

edic

ines

in s

ome

coun

tries

bee

n so

ld a

nd a

dmin

iste

red

as

race

mat

es in

stea

d of

as

the

desi

red

enan

tiom

er w

ith th

e as

soci

ated

ther

apeu

tic

activ

ity?

Can

you

thin

k of

any

dru

gs o

r med

icin

es w

hich

may

ser

ve a

s go

od

case

stu

dies

for t

his?

Theo

ry o

f kno

wle

dge:

• Th

e ex

iste

nce

of o

ptic

al is

omer

s pr

ovid

e in

dire

ct e

vide

nce

for a

tetra

hedr

ally

bo

nded

car

bon

atom

. Whi

ch w

ays

of k

now

ing

allo

w u

s to

con

nect

indi

rect

ev

iden

ce to

our

theo

ries?

• S

tere

oiso

mer

ism

can

be

inve

stig

ated

by

phys

ical

and

com

pute

r mod

els.

Wha

t is

the

role

of s

uch

mod

els

in o

ther

are

as o

f kno

wle

dge?

• O

ne o

f the

cha

lleng

es fo

r the

sci

entis

t and

the

artis

t is

to re

pres

ent t

he th

ree-

dim

ensi

onal

wor

ld in

two

dim

ensi

ons.

Wha

t are

the

sim

ilarit

ies

and

diffe

renc

es

in th

e tw

o ap

proa

ches

? W

hat i

s th

e ro

le o

f the

diff

eren

t way

s of

kno

win

g in

the

two

appr

oach

es?

Util

izat

ion:

• M

any

of th

e dr

ugs

deriv

ed fr

om n

atur

al s

ourc

es a

re c

hira

l and

incl

ude

nico

tine,

do

pam

ine,

thyr

oxin

e an

d na

prox

en.

• Th

e ro

le o

f ste

reoc

hem

istry

in v

isio

n sc

ienc

e an

d fo

od s

cien

ce.

• In

man

y pe

rfum

es, s

tere

oche

mis

try o

ften

can

be d

eem

ed m

ore

impo

rtant

than

ch

emic

al c

ompo

sitio

n.

Isom

eris

m

Ster

eois

omer

ism

Conf

igur

atio

nal

Isom

eris

mCo

nfor

mat

iona

l Is

omer

ism

Stru

ctur

al

Isom

eris

m


Chemistry guide102

20.3

Ste

reoi

som

eris

m

• C

is-tr

ans

isom

ers

can

occu

r in

alke

nes

or c

yclo

alka

nes

(or h

eter

oana

logu

es)

and

diffe

r in

the

posi

tions

of a

tom

s (o

r gro

ups)

rela

tive

to a

refe

renc

e pl

ane.

A

ccor

ding

to IU

PA

C, E

/Z is

omer

s re

fer t

o al

kene

s of

the

form

R1R

2C=C

R3R

4 (R

1 ≠

R2,

R3

≠ R

4) w

here

nei

ther

R1

nor R

2 ne

ed b

e di

ffere

nt fr

om R

3 or

R4.

• A

chi

ral c

arbo

n is

a c

arbo

n jo

ined

to fo

ur d

iffer

ent a

tom

s or

gro

ups.

• A

n op

tical

ly a

ctiv

e co

mpo

und

can

rota

te th

e pl

ane

of p

olar

ized

ligh

t as

it pa

sses

th

roug

h a

solu

tion

of th

e co

mpo

und.

Opt

ical

isom

ers

are

enan

tiom

ers.

E

nant

iom

ers

are

non-

supe

rimpo

seab

le m

irror

imag

es o

f eac

h ot

her.

Dia

ster

eom

ers

are

not m

irror

imag

es o

f eac

h ot

her.

• A

race

mic

mix

ture

(or r

acem

ate)

is a

mix

ture

of t

wo

enan

tiom

ers

in e

qual

am

ount

s an

d is

opt

ical

ly in

activ

e.

App

licat

ions

and

ski

lls:

• C

onst

ruct

ion

of 3

-D m

odel

s (r

eal o

r virt

ual)

of a

wid

e ra

nge

of s

tere

oiso

mer

s.

• E

xpla

natio

n of

ste

reoi

som

eris

m in

non

-cyc

lic a

lken

es a

nd C

3 an

d C

4 cy

cloa

lkan

es.

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

cs 1

0.1

and

10.2

—or

gani

c ch

emis

try

Opt

ion

B.4

—ca

rboh

ydra

tes

Opt

ion

B.1

0—st

ereo

chem

istry

in b

iom

olec

ules

O

ptio

n D

.7—

impo

rtanc

e of

chi

ralit

y an

d dr

ug a

ctio

n

Aim

s

• A

im 6

: Exp

erim

ents

cou

ld in

clud

e th

e sy

nthe

sis

and

char

acte

rizat

ion

of a

n en

antio

mer

(eg

(-) m

enth

ol) o

r the

reso

lutio

n of

a ra

cem

ic m

ixtu

re.


Chemistry guide 103

20.3

Ste

reoi

som

eris

m

• C

ompa

rison

bet

wee

n th

e ph

ysic

al a

nd c

hem

ical

pro

perti

es o

f ena

ntio

mer

s.

• D

escr

iptio

n an

d ex

plan

atio

n of

opt

ical

isom

ers

in s

impl

e or

gani

c m

olec

ules

.

• D

istin

ctio

n be

twee

n op

tical

isom

ers

usin

g a

pola

rimet

er.

Gui

danc

e:

• Th

e te

rm g

eom

etric

isom

ers

as re

com

men

ded

by IU

PA

C is

now

obs

olet

e an

d ci

s-tra

ns is

omer

s an

d E

/Z is

omer

s sh

ould

be

enco

urag

ed in

the

teac

hing

pr

ogra

mm

e.

• In

the

E/Z

sys

tem

, the

gro

up o

f hig

hest

Cah

n–In

gold

–Pre

log

prio

rity

atta

ched

to

one

of th

e te

rmin

al d

oubl

y bo

nded

ato

ms

of th

e al

kene

(ie

R1

or R

2) is

co

mpa

red

with

the

grou

p of

hig

hest

pre

cede

nce

atta

ched

to th

e ot

her (

ie R

3 or

R

4). T

he s

tere

oiso

mer

is Z

if th

e gr

oups

lie

on th

e sa

me

side

of a

refe

renc

e pl

ane

pass

ing

thro

ugh

the

doub

le b

ond

and

perp

endi

cula

r to

the

plan

e co

ntai

ning

the

bond

s lin

king

the

grou

ps to

the

doub

le-b

onde

d at

oms;

the

othe

r st

ereo

isom

er is

des

igna

ted

as E

.

• W

edge

-das

h ty

pe re

pres

enta

tions

invo

lvin

g ta

pere

d bo

nds

shou

ld b

e us

ed fo

r re

pres

enta

tions

of o

ptic

al is

omer

s.

Topic 21: Measurement and analysis

Chemistry guide104

Esse

ntia

l ide

a: A

lthou

gh s

pect

rosc

opic

cha

ract

eriz

atio

n te

chni

ques

form

the

back

bone

of s

truct

ural

iden

tific

atio

n of

com

poun

ds, t

ypic

ally

no

one

tech

niqu

e re

sults

in a

full

stru

ctur

al id

entif

icat

ion

of a

mol

ecul

e.

21.1

Spe

ctro

scop

ic id

entif

icat

ion

of o

rgan

ic c

ompo

unds

Nat

ure

of s

cien

ce:

Impr

ovem

ents

in m

oder

n in

stru

men

tatio

n—ad

vanc

es in

spe

ctro

scop

ic te

chni

ques

(IR

, 1 H N

MR

and

MS)

hav

e re

sulte

d in

det

aile

d kn

owle

dge

of th

e st

ruct

ure

of c

ompo

unds

. (1.

8)

Und

erst

andi

ngs:

• S

truct

ural

iden

tific

atio

n of

com

poun

ds in

volv

es s

ever

al d

iffer

ent a

naly

tical

te

chni

ques

incl

udin

g IR

, 1 H N

MR

and

MS

.

• In

a h

igh

reso

lutio

n 1 H

NM

R s

pect

rum

, sin

gle

peak

s pr

esen

t in

low

reso

lutio

n ca

n sp

lit in

to fu

rther

clu

ster

s of

pea

ks.

• Th

e st

ruct

ural

tech

niqu

e of

sin

gle

crys

tal X

-ray

crys

tallo

grap

hy c

an b

e us

ed to

id

entif

y th

e bo

nd le

ngth

s an

d bo

nd a

ngle

s of

cry

stal

line

com

poun

ds.

App

licat

ions

and

ski

lls:

• E

xpla

natio

n of

the

use

of te

tram

ethy

lsila

ne (T

MS

) as

the

refe

renc

e st

anda

rd.

• D

educ

tion

of th

e st

ruct

ure

of a

com

poun

d gi

ven

info

rmat

ion

from

a ra

nge

of

anal

ytic

al c

hara

cter

izat

ion

tech

niqu

es (X

-ray

crys

tallo

grap

hy, I

R, 1 H

NM

R a

nd

MS

).

Gui

danc

e:

• S

tude

nts

shou

ld b

e ab

le to

inte

rpre

t the

follo

win

g fro

m 1 H

NM

R s

pect

ra:

num

ber o

f pea

ks, a

rea

unde

r eac

h pe

ak, c

hem

ical

shi

ft an

d sp

littin

g pa

ttern

s.

Trea

tmen

t of s

pin-

spin

cou

plin

g co

nsta

nts

will

not

be

asse

ssed

but

stu

dent

s sh

ould

be

fam

iliar

with

sin

glet

s, d

oubl

ets,

trip

lets

and

qua

rtets

.

• H

igh

reso

lutio

n 1 H

NM

R s

houl

d be

cov

ered

.

Inte

rnat

iona

l-min

dedn

ess:

• Th

e ch

emic

al c

omm

unity

ofte

n sh

ares

che

mic

al s

truct

ural

info

rmat

ion

on th

e in

tern

atio

nal s

tage

. The

Cam

brid

ge C

ryst

allo

grap

hic

Dat

abas

e, C

hem

Spi

der

deve

lope

d by

the

Roy

al S

ocie

ty o

f Che

mis

try a

nd th

e P

rote

in D

ata

Ban

k (R

CS

B P

DB

) (at

Bro

okha

ven

Nat

iona

l Lab

orat

ory,

US

A) a

re e

xam

ples

whi

ch

high

light

the

inte

rnat

iona

l nat

ure

of th

e sc

ient

ific

com

mun

ity.

Theo

ry o

f kno

wle

dge:

• Th

e in

tens

ity ra

tio o

f the

line

s in

the

high

reso

lutio

n N

MR

spe

ctru

m is

giv

en b

y th

e nu

mbe

rs in

Pas

cal's

tria

ngle

, a m

athe

mat

ical

pat

tern

kno

wn

inde

pend

ently

ov

er a

thou

sand

yea

rs a

go b

y a

num

ber o

f diff

eren

t cul

ture

s. W

hy is

m

athe

mat

ics

such

an

effe

ctiv

e to

ol in

sci

ence

? Is

mat

hem

atic

s th

e sc

ienc

e of

pa

ttern

s?

Util

izat

ion:

• P

roto

ns in

wat

er m

olec

ules

with

in h

uman

cel

ls c

an b

e de

tect

ed b

y m

agne

tic

reso

nanc

e im

agin

g (M

RI),

giv

ing

a th

ree-

dim

ensi

onal

vie

w o

f org

ans

in th

e hu

man

bod

y. W

hy is

MR

I rep

laci

ng c

ompu

teriz

ed to

mog

raph

y (C

T) s

cans

for

som

e ap

plic

atio

ns b

ut is

use

d as

a c

ompl

emen

tary

tech

niqu

e fo

r oth

ers?

• M

S (a

nd o

ther

tech

niqu

es s

uch

as T

LC, G

C, G

C-M

S a

nd H

PLC

) can

be

used

in

fore

nsic

inve

stig

atio

ns a

t crim

e sc

enes

.

• A

naly

tical

tech

niqu

es c

an b

e us

ed to

test

for d

rug

abus

e by

hig

h-pe

rform

ance

at

hlet

es.

Add

ition

al h

ighe

r lev

el

Topi

c 21

: Mea

sure

men

t and

ana

lysis

2

hour

s

Topic 21: Measurement and analysis

Chemistry guide 105

21.1

Spe

ctro

scop

ic id

entif

icat

ion

of o

rgan

ic c

ompo

unds

• Th

e pr

ecis

e de

tails

of s

ingl

e cr

ysta

l X-ra

y cr

ysta

llogr

aphy

nee

d no

t be

know

n in

de

tail,

but

stu

dent

s sh

ould

be

awar

e of

the

exis

tenc

e of

this

stru

ctur

al te

chni

que

in th

e w

ider

con

text

of s

truct

ural

iden

tific

atio

n of

bot

h in

orga

nic

and

orga

nic

com

poun

ds.

• Th

e op

erat

ing

prin

cipl

es a

re n

ot re

quire

d fo

r any

of t

hese

met

hods

.

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 11

.3—

spec

trosc

opic

iden

tific

atio

n of

com

poun

ds

Opt

ion

B.2

—ch

rom

atog

raph

y an

d pr

otei

n se

para

tion

O

ptio

n B

.9—

chro

mat

ogra

phy

and

pigm

ents

O

ptio

n D

.7—

chira

l aux

iliar

ies

Aim

s:

• A

im 7

: Spe

ctra

l dat

abas

es c

an b

e us

ed h

ere.

Core topics

Chemistry guide106

Esse

ntia

l ide

a: M

ater

ials

sci

ence

invo

lves

und

erst

andi

ng th

e pr

oper

ties

of a

mat

eria

l, an

d th

en a

pply

ing

thos

e pr

oper

ties

to d

esire

d st

ruct

ures

.

A.1

Mat

eria

ls s

cien

ce in

trod

uctio

n

Nat

ure

of s

cien

ce:

Impr

ovem

ents

in te

chno

logy

—di

ffere

nt m

ater

ials

wer

e us

ed fo

r diff

eren

t pur

pose

s be

fore

the

deve

lopm

ent o

f a s

cien

tific

und

erst

andi

ng o

f the

ir pr

oper

ties.

(1.8

)

Pat

tern

s in

sci

ence

—hi

stor

y ha

s ch

arac

teriz

ed c

ivili

zatio

ns b

y th

e m

ater

ials

they

use

d: S

tone

Age

, Bro

nze

Age

and

Iron

Age

. The

re a

re v

ario

us w

ays

of c

lass

ifyin

g m

ater

ials

ac

cord

ing

to d

esire

d pa

ttern

s. (3

.1)

Und

erst

andi

ngs:

• M

ater

ials

are

cla

ssifi

ed b

ased

on

thei

r use

s, p

rope

rties

, or b

ondi

ng a

nd

stru

ctur

e.

• Th

e pr

oper

ties

of a

mat

eria

l bas

ed o

n th

e de

gree

of c

oval

ent,

ioni

c or

met

allic

ch

arac

ter i

n a

com

poun

d ca

n be

ded

uced

from

its

posi

tion

on a

bon

ding

tri

angl

e.

• C

ompo

site

s ar

e m

ixtu

res

in w

hich

mat

eria

ls a

re c

ompo

sed

of tw

o di

stin

ct

phas

es, a

rein

forc

ing

phas

e th

at is

em

bedd

ed in

a m

atrix

pha

se.

App

licat

ions

and

ski

lls:

• U

se o

f bon

d tri

angl

e di

agra

ms

for b

inar

y co

mpo

unds

from

ele

ctro

nega

tivity

da

ta.

• E

valu

atio

n of

var

ious

way

s of

cla

ssify

ing

mat

eria

ls.

• R

elat

ing

phys

ical

cha

ract

eris

tics

(mel

ting

poin

t, pe

rmea

bilit

y, c

ondu

ctiv

ity,

elas

ticity

, brit

tlene

ss) o

f a m

ater

ial t

o its

bon

ding

and

stru

ctur

es (p

acki

ng

arra

ngem

ents

, ele

ctro

n m

obili

ty, a

bilit

y of

ato

ms

to s

lide

rela

tive

to o

ne

anot

her).

Inte

rnat

iona

l-min

dedn

ess:

• W

hat m

ater

ials

wer

e us

ed b

y an

cien

t civ

iliza

tions

, suc

h as

the

Azt

ecs,

Rom

ans,

an

d C

hine

se?

Eve

n th

ough

thes

e an

cien

t civ

iliza

tions

wer

e lo

cate

d in

ge

ogra

phic

ally

div

erse

loca

tions

, the

mat

eria

ls th

ey u

sed

wer

e si

mila

r.

Theo

ry o

f kno

wle

dge:

• A

lthou

gh it

is c

onve

nien

t to

clas

sify

mat

eria

ls in

to c

ateg

orie

s no

sin

gle

clas

sific

atio

n is

“per

fect

”. H

ow d

o w

e ev

alua

te th

e di

ffere

nt c

lass

ifica

tion

syst

ems

we

use

in th

e di

ffere

nt a

reas

of k

now

ledg

e? H

ow d

oes

our n

eed

to

cate

goriz

e th

e w

orld

hel

p an

d hi

nder

the

purs

uit o

f kno

wle

dge?

Util

izat

ion:

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 4.

2—th

e ro

le o

f ele

ctro

nega

tivity

in b

ondi

ng ty

pes

Core

topi

cs

Opt

ion

A: M

ater

ials

15

/25

hour

s

Core topics

Chemistry guide 107

A.1

Mat

eria

ls s

cien

ce in

trod

uctio

n

Gui

danc

e:

• P

erm

eabi

lity

to m

oist

ure

shou

ld b

e co

nsid

ered

with

resp

ect t

o bo

ndin

g an

d si

mpl

e pa

ckin

g ar

rang

emen

ts.

• C

onsi

der p

rope

rties

of m

etal

s, p

olym

ers

and

cera

mic

s in

term

s of

met

allic

, co

vale

nt, a

nd io

nic

bond

ing.

• S

ee s

ectio

n 29

of t

he d

ata

book

let f

or a

tria

ngul

ar b

ondi

ng d

iagr

am.

Aim

s:

• A

ims

1 an

d 3:

Inve

stig

atio

n of

tetra

hedr

a of

stru

ctur

e an

d bo

ndin

g ty

pes

and

whe

re c

oval

ent n

etw

orks

and

pol

ymer

s fit

on

thes

e di

agra

ms.

• A

im 6

: Exp

erim

ents

cou

ld in

clud

e in

vest

igat

ing

the

stre

tchi

ng o

f rub

ber b

ands

un

der d

iffer

ent c

hem

ical

env

ironm

ents

, or p

rope

rties

of m

etal

s, p

olym

ers,

ce

ram

ics,

or c

ompo

site

s, m

akin

g th

in c

oncr

ete

slab

s fro

m v

ario

us ra

tios

of

cem

ent,

grav

el, a

nd s

and

and

inve

stig

atin

g th

e br

eaki

ng s

treng

th u

pon

dryi

ng.

Core topics

Chemistry guide108

Esse

ntia

l ide

a: M

etal

s ca

n be

ext

ract

ed fr

om th

eir

ores

and

allo

yed

for

desi

red

char

acte

ristic

s. IC

P-M

S/O

ES

Spe

ctro

scop

y io

nize

s m

etal

s an

d us

es m

ass

and

emis

sion

sp

ectra

for a

naly

sis.

A.2

Met

als

and

indu

ctiv

ely

coup

led

plas

ma

(ICP)

spe

ctro

scop

y

Nat

ure

of s

cien

ce:

Dev

elop

men

t of n

ew in

stru

men

ts a

nd te

chni

ques

—IC

P s

pect

rosc

opy,

dev

elop

ed fr

om a

n un

ders

tand

ing

of s

cien

tific

prin

cipl

es, c

an b

e us

ed to

iden

tify

and

quan

tify

trace

am

ount

s of

met

als.

(1.8

)

Det

ails

of d

ata—

with

the

disc

over

y th

at tr

ace

amou

nts

of c

erta

in m

ater

ials

can

gre

atly

enh

ance

a m

etal

’s p

erfo

rman

ce, a

lloyi

ng w

as in

itial

ly m

ore

of a

n ar

t tha

n a

scie

nce.

(3

.1)

Und

erst

andi

ngs:

• R

educ

tion

by c

oke

(car

bon)

, a m

ore

reac

tive

met

al, o

r ele

ctro

lysi

s ar

e m

eans

of

obta

inin

g so

me

met

als

from

thei

r ore

s.

• Th

e re

latio

nshi

p be

twee

n ch

arge

and

the

num

ber o

f mol

es o

f ele

ctro

ns is

giv

en

by F

arad

ay’s

con

stan

t, F.

• A

lloys

are

hom

ogen

eous

mix

ture

s of

met

als

with

oth

er m

etal

s or

non

-met

als.

• D

iam

agne

tic a

nd p

aram

agne

tic c

ompo

unds

diff

er in

ele

ctro

n sp

in p

airin

g an

d th

eir b

ehav

iour

in m

agne

tic fi

elds

.

• Tr

ace

amou

nts

of m

etal

s ca

n be

iden

tifie

d an

d qu

antif

ied

by io

nizi

ng th

em w

ith

argo

n ga

s pl

asm

a in

Indu

ctiv

ely

Cou

pled

Pla

sma

(ICP

) Spe

ctro

scop

y us

ing

Mas

s S

pect

rosc

opy

ICP

-MS

and

Opt

ical

Em

issi

on S

pect

rosc

opy

ICP

-OE

S.

App

licat

ions

and

ski

lls:

• D

educ

tion

of re

dox

equa

tions

for t

he re

duct

ion

of m

etal

s.

• R

elat

ing

the

met

hod

of e

xtra

ctio

n to

the

posi

tion

of a

met

al o

n th

e ac

tivity

se

ries.

• E

xpla

natio

n of

the

prod

uctio

n of

alu

min

ium

by

the

elec

troly

sis

of a

lum

ina

in

mol

ten

cryo

lite

• E

xpla

natio

n of

how

allo

ying

alte

rs p

rope

rties

of m

etal

s.

Inte

rnat

iona

l-min

dedn

ess:

• Th

e us

e of

rare

ear

th m

etal

s, o

r exo

tic m

iner

als,

has

gro

wn

dram

atic

ally

. The

y ar

e us

ed in

gre

en te

chno

logy

, med

icin

es, l

aser

s, w

eapo

ns te

chno

logy

and

el

sew

here

. The

y ar

e ex

pens

ive

to o

btai

n bu

t gro

win

g in

dem

and.

Wha

t ha

ppen

s if

rare

ear

th re

serv

es a

re c

ontro

lled

only

by

a fe

w c

ount

ries

but a

re

used

by

man

y co

untri

es?

Theo

ry o

f kno

wle

dge:

• W

hat f

acto

rs/o

utco

mes

sho

uld

be u

sed

to d

eter

min

e ho

w ti

me,

mon

ey, a

nd

effo

rt is

spe

nt o

n sc

ient

ific

rese

arch

? W

ho d

ecid

es w

hich

kno

wle

dge

is to

be

purs

ued?

Util

izat

ion:

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

cs 2

.1 a

nd 1

2.1—

mas

s sp

ectro

met

ry

Topi

c 2.

2—em

issi

on s

pect

ra

Topi

c 9.

1—ox

idat

ion

and

redu

ctio

n

Aim

s:

• A

im 6

: Exp

erim

ents

cou

ld in

clud

e ca

lcul

atin

g th

e Fa

rada

y co

nsta

nt v

ia

elec

troly

sis

of a

queo

us c

oppe

r sul

fate

, sol

ving

for t

he c

once

ntra

tion

of a

nic

kel

or c

oppe

r sol

utio

n us

ing

Bee

r’s la

w a

nd s

pect

roph

otom

etry

. Ana

lysi

s of

allo

y co

mpo

sitio

n la

bs c

ould

als

o be

con

duct

ed s

uch

as c

olor

imet

ric d

eter

min

atio

n of

m

anga

nese

in a

pap

er c

lip o

r gra

vim

etric

ana

lysi

s of

silv

er o

r cop

per i

n a

coin

.

Core topics

Chemistry guide 109

A.2

Met

als

and

indu

ctiv

ely

coup

led

plas

ma

(ICP)

spe

ctro

scop

y

• S

olvi

ng s

toic

hiom

etric

pro

blem

s us

ing

Fara

day’

s co

nsta

nt b

ased

on

mas

s de

posi

ts in

ele

ctro

lysi

s.

• D

iscu

ssio

n of

par

amag

netis

m a

nd d

iam

agne

tism

in re

latio

n to

ele

ctro

n st

ruct

ure

of m

etal

s.

• E

xpla

natio

n of

the

plas

ma

stat

e an

d its

pro

duct

ion

in IC

P- M

S/O

ES

.

• Id

entif

y m

etal

s an

d ab

unda

nces

from

sim

ple

data

and

cal

ibra

tion

curv

es

prov

ided

from

ICP

-MS

and

ICP

-OE

S.

• E

xpla

natio

n of

the

sepa

ratio

n an

d qu

antif

icat

ion

of m

etal

lic io

ns b

y M

S a

nd

OE

S.

• U

ses

of IC

P-M

S a

nd IC

P-O

ES

.

Gui

danc

e:

• Fa

rada

y’s

cons

tant

is g

iven

in th

e da

ta b

ookl

et in

sec

tion

2.

• D

etai

ls o

f ope

ratin

g pa

rts o

f IC

P-M

S a

nd IC

P-O

ES

inst

rum

ents

will

not

be

asse

ssed

.

• O

nly

anal

ysis

of m

etal

s sh

ould

be

cove

red.

• Th

e im

porta

nce

of c

alib

ratio

n sh

ould

be

cove

red.

• A

im 7

: Ani

mat

ions

invo

lvin

g IC

P c

ould

be

used

.

• A

im 7

: Sim

ulat

ions

and

virt

ual e

xper

imen

ts c

ould

be

used

to in

vest

igat

e se

mic

ondu

ctor

s.

Core topics

Chemistry guide110

Esse

ntia

l ide

a: C

atal

ysts

wor

k by

pro

vidi

ng a

n al

tern

ate

reac

tion

path

way

for t

he re

actio

n. C

atal

ysts

alw

ays

incr

ease

the

rate

of t

he re

actio

n an

d ar

e le

ft un

chan

ged

at th

e en

d of

the

reac

tion.

A.3

Cat

alys

ts

Nat

ure

of s

cien

ce:

Use

of m

odel

s—ca

taly

sts

wer

e us

ed to

incr

ease

reac

tion

rate

s be

fore

the

deve

lopm

ent o

f an

unde

rsta

ndin

g of

how

they

wor

k. T

his

led

to m

odel

s th

at a

re c

onst

antly

bei

ng

test

ed a

nd im

prov

ed. (

1.10

)

Und

erst

andi

ngs:

• R

eact

ants

ads

orb

onto

het

erog

eneo

us c

atal

ysts

at a

ctiv

e si

tes

and

the

prod

ucts

des

orb.

• H

omog

eneo

us c

atal

ysts

che

mic

ally

com

bine

with

the

reac

tant

s to

form

a

tem

pora

ry a

ctiv

ated

com

plex

or a

reac

tion

inte

rmed

iate

.

• Tr

ansi

tion

met

al c

atal

ytic

pro

perti

es d

epen

d on

the

adso

rptio

n/ab

sorp

tion

prop

ertie

s of

the

met

al a

nd th

e va

riabl

e ox

idat

ion

stat

es.

• Ze

olite

s ac

t as

sele

ctiv

e ca

taly

sts

beca

use

of th

eir c

age

stru

ctur

e.

• C

atal

ytic

par

ticle

s ar

e ne

arly

alw

ays

nano

parti

cles

that

hav

e la

rge

surfa

ce

area

s pe

r uni

t mas

s.

App

licat

ions

and

ski

lls:

• E

xpla

natio

n of

fact

ors

invo

lved

in c

hoos

ing

a ca

taly

st fo

r a p

roce

ss.

• D

escr

iptio

n of

how

met

als

wor

k as

het

erog

eneo

us c

atal

ysts

.

• D

escr

iptio

n of

the

bene

fits

of n

anoc

atal

ysts

in in

dust

ry.

Gui

danc

e:

• C

onsi

der c

atal

ytic

pro

perti

es s

uch

as s

elec

tivity

for o

nly

the

desi

red

prod

uct,

effic

ienc

y, a

bilit

y to

wor

k in

mild

/sev

ere

cond

ition

s, e

nviro

nmen

tal i

mpa

ct a

nd

impu

ritie

s.

• Th

e us

e of

car

bon

nano

cata

lyst

s sh

ould

be

cove

red.

Inte

rnat

iona

l-min

dedn

ess:

• P

alla

dium

, pla

tinum

and

rhod

ium

are

com

mon

cat

alys

ts th

at a

re u

sed

in

cata

lytic

con

verte

rs. B

ecau

se o

f the

val

ue o

f the

se m

etal

s, c

atal

ytic

con

verte

r th

efts

are

on

the

rise.

Theo

ry o

f kno

wle

dge:

• S

ome

mat

eria

ls u

sed

as e

ffect

ive

cata

lyst

s ar

e to

xic

and

harm

ful t

o th

e en

viro

nmen

t. Is

env

ironm

enta

l deg

rada

tion

just

ified

in th

e pu

rsui

t of

know

ledg

e?

Util

izat

ion:

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

cs 6

.1 a

nd 1

6.1—

reac

tion

mec

hani

sms

Topi

c 10

.2—

este

rific

atio

n an

d hy

drog

enat

ion

reac

tions

To

pic

16.2

—ac

tivat

ion

ener

gy

Opt

ion

B.1

0—hy

drog

enat

ion

of fa

ts

Aim

s:

• A

ims

1 an

d 3:

Inve

stig

ate

vario

us c

atal

ysts

for b

oth

the

bene

fits

and

risks

.

• A

im 6

: Exp

erim

ents

cou

ld in

clud

e in

vest

igat

ing

the

deco

mpo

sitio

n of

pot

assi

um

sodi

um ta

rtrat

e w

ith c

obal

t chl

orid

e an

d th

e de

com

posi

tion

of h

ydro

gen

pero

xide

with

man

gane

se (I

V) o

xide

.

• A

im 6

: An

ion

exch

ange

usi

ng z

eolit

e co

uld

be e

xplo

red.

• A

im 7

: Virt

ual e

xper

imen

ts a

nd s

imul

atio

ns in

volv

ing

nano

parti

cles

as

cata

lyst

s co

uld

be d

one

here

.

Core topics

Chemistry guide 111

Esse

ntia

l ide

a: L

iqui

d cr

ysta

ls a

re fl

uids

that

hav

e ph

ysic

al p

rope

rties

whi

ch a

re d

epen

dent

on

mol

ecul

ar o

rient

atio

n re

lativ

e to

som

e fix

ed a

xis

in th

e m

ater

ial.

A.4

Liq

uid

crys

tals

Nat

ure

of s

cien

ce

Ser

endi

pity

and

sci

entif

ic d

isco

verie

s—Fr

iedr

ich

Rei

nitz

er a

ccid

ently

dis

cove

red

flow

ing

liqui

d cr

ysta

ls in

188

8 w

hile

exp

erim

entin

g on

cho

lest

erol

ben

zoat

e. (1

.4)

Und

erst

andi

ngs:

• Li

quid

cry

stal

s ar

e flu

ids

that

hav

e ph

ysic

al p

rope

rties

(ele

ctric

al, o

ptic

al a

nd

elas

ticity

) tha

t are

dep

ende

nt o

n m

olec

ular

orie

ntat

ion

to s

ome

fixed

axi

s in

the

mat

eria

l.

• Th

erm

otro

pic

liqui

d-cr

ysta

l mat

eria

ls a

re p

ure

subs

tanc

es th

at s

how

liqu

id-

crys

tal b

ehav

iour

ove

r a te

mpe

ratu

re ra

nge.

• Ly

otro

pic

liqui

d cr

ysta

ls a

re s

olut

ions

that

sho

w th

e liq

uid-

crys

tal s

tate

ove

r a

(cer

tain

) ran

ge o

f con

cent

ratio

ns.

• N

emat

ic li

quid

cry

stal

pha

se is

cha

ract

eriz

ed b

y ro

d sh

aped

mol

ecul

es w

hich

ar

e ra

ndom

ly d

istri

bute

d bu

t on

aver

age

alig

n in

the

sam

e di

rect

ion.

App

licat

ions

and

ski

lls:

• D

iscu

ssio

n of

the

prop

ertie

s ne

eded

for a

sub

stan

ce to

be

used

in li

quid

-cry

stal

di

spla

ys (L

CD

).

• E

xpla

natio

n of

liqu

id-c

ryst

al b

ehav

iour

on

a m

olec

ular

leve

l.

Gu i

danc

e:

• P

rope

rties

nee

ded

for l

iqui

d cr

ysta

ls in

clud

e: c

hem

ical

ly s

tabl

e, a

pha

se w

hich

is

sta

ble

over

a s

uita

ble

tem

pera

ture

rang

e, p

olar

so

they

can

cha

nge

orie

ntat

ion

whe

n an

ele

ctric

fiel

d is

app

lied,

and

rapi

d sw

itchi

ng s

peed

.

• S

oap

and

wat

er is

an

exam

ple

of ly

otro

pic

liqui

d cr

ysta

ls a

nd th

e bi

phen

yl

nitri

les

are

exam

ples

of t

herm

otro

pic

liqui

d cr

ysta

ls.

• Li

quid

cry

stal

beh

avio

ur s

houl

d be

lim

ited

to th

e bi

phen

yl n

itrile

s.

• S

mec

tics

and

othe

r liq

uid

crys

tals

type

s ne

ed n

ot b

e di

scus

sed.

Inte

rnat

iona

l-min

dedn

ess:

• Th

e pr

oduc

tion

of m

any

elec

troni

c go

ods

is c

once

ntra

ted

in a

reas

of t

he w

orld

w

here

the

wor

king

con

ditio

ns m

ay n

ot b

e id

eal.

Sho

uld

ther

e be

inte

rnat

iona

lly

set l

abou

r sta

ndar

ds fo

r all

wor

kers

? W

hat i

mpl

icat

ions

wou

ld th

is h

ave

on th

e co

st o

f con

sum

er g

oods

?

Theo

ry o

f kno

wle

dge:

• D

evel

opm

ents

in te

chno

logy

mea

n th

at w

e ca

n st

ore

mor

e an

d m

ore

info

rmat

ion

avai

labl

e on

an

incr

easi

ngly

sm

alle

r sca

le. D

oes

this

mea

n th

at w

e ca

n ac

cess

mor

e kn

owle

dge?

Util

izat

ion:

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 20

.3—

chira

lity

and

ster

eois

omer

s

Aim

s:

• A

im 6

: Exp

erim

ents

cou

ld in

clud

e in

vest

igat

ing

a th

erm

otro

pic

liqui

d cr

ysta

l and

th

e te

mpe

ratu

re ra

nge

whi

ch a

ffect

s th

ese

crys

tals

.

• A

im 7

: Com

pute

r ani

mat

ions

cou

ld b

e us

ed to

inve

stig

ate

ther

mot

ropi

c liq

uid

crys

tals

.

Core topics

Chemistry guide112

Esse

ntia

l ide

a: P

olym

ers

are

mad

e up

of r

epea

ting

mon

omer

uni

ts w

hich

can

be

man

ipul

ated

in v

ario

us w

ays

to g

ive

stru

ctur

es w

ith d

esire

d pr

oper

ties.

A.5

Pol

ymer

s

Nat

ure

of s

cien

ce:

Adv

ance

s in

tech

nolo

gy—

as a

resu

lt of

adv

ance

s in

tech

nolo

gy (X

-ray

diffr

actio

n, s

cann

ing

tunn

ellin

g el

ectro

n m

icro

scop

es, e

tc),

scie

ntis

ts h

ave

been

abl

e to

und

erst

and

wha

t occ

urs

on th

e m

olec

ular

leve

l and

man

ipul

ate

mat

ter i

n ne

w w

ays.

Thi

s al

low

s ne

w p

olym

ers

to b

e de

velo

ped.

(3.7

)

Theo

ries

can

be s

uper

sede

d—S

taud

inge

r's p

ropo

sal o

f mac

rom

olec

ules

mad

e of

man

y re

peat

ing

units

was

inte

gral

in th

e de

velo

pmen

t of p

olym

er s

cien

ce. (

1.9)

Eth

ics

and

risk

asse

ssm

ent—

poly

mer

dev

elop

men

t and

use

has

gro

wn

quic

ker t

han

an u

nder

stan

ding

of t

he ri

sks

invo

lved

, suc

h as

recy

clin

g or

pos

sibl

e ca

rcin

ogen

ic

prop

ertie

s. (4

.5)

Und

erst

andi

ngs:

• Th

erm

opla

stic

s so

ften

whe

n he

ated

and

har

den

whe

n co

oled

.

• A

ther

mos

ettin

g po

lym

er is

a p

repo

lym

er in

a s

oft s

olid

or v

isco

us s

tate

that

ch

ange

s irr

ever

sibl

y in

to a

har

dene

d th

erm

oset

by

curin

g.

• E

last

omer

s ar

e fle

xibl

e an

d ca

n be

def

orm

ed u

nder

forc

e bu

t will

retu

rn to

ne

arly

thei

r orig

inal

sha

pe o

nce

the

stre

ss is

rele

ased

.

• H

igh

dens

ity p

olye

then

e (H

DP

E) h

as n

o br

anch

ing

allo

win

g ch

ains

to b

e pa

cked

toge

ther

.

• Lo

w d

ensi

ty p

olye

then

e (L

DP

E) h

as s

ome

bran

chin

g an

d is

mor

e fle

xibl

e.

• P

last

iciz

ers

adde

d to

a p

olym

er in

crea

se th

e fle

xibi

lity

by w

eake

ning

the

inte

rmol

ecul

ar fo

rces

bet

wee

n th

e po

lym

er c

hain

s.

• A

tom

eco

nom

y is

a m

easu

re o

f effi

cien

cy a

pplie

d in

gre

en c

hem

istry

.

• Is

otac

tic a

dditi

on p

olym

ers

have

sub

stitu

ents

on

the

sam

e si

de.

• A

tact

ic a

dditi

on p

olym

ers

have

the

subs

titue

nts

rand

omly

pla

ced.

App

licat

ions

and

ski

lls:

• D

escr

iptio

n of

the

use

of p

last

iciz

ers

in p

olyv

inyl

chl

orid

e an

d vo

latil

e hy

droc

arbo

ns in

the

form

atio

n of

exp

ande

d po

lyst

yren

e.

Inte

rnat

iona

l-min

dedn

ess:

• P

last

ics

wer

e vi

rtual

ly u

nhea

rd o

f prio

r to

the

seco

nd w

orld

war

. How

has

the

intro

duct

ion

of p

last

ics

affe

cted

the

wor

ld e

cono

mic

ally

, soc

ially

and

en

viro

nmen

tally

?

Util

izat

ion:

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

cs 1

0.2

and

20.1

—ad

ditio

n an

d co

nden

satio

n re

actio

ns

Aim

s:

• A

im 6

: Phy

sica

l pro

perti

es o

f hig

h an

d lo

w d

ensi

ty p

olye

then

e co

uld

be

inve

stig

ated

or s

ynth

esis

of a

pol

yest

er, p

olya

mid

e or

oth

er p

olym

er c

ould

be

quan

titat

ivel

y pe

rform

ed to

mea

sure

ato

m e

ffici

ency

.

Core topics

Chemistry guide 113

A.5

Pol

ymer

s

• S

olvi

ng p

robl

ems

and

eval

uatin

g at

om e

cono

my

in s

ynth

esis

reac

tions

.

• D

escr

iptio

n of

how

the

prop

ertie

s of

pol

ymer

s de

pend

on

thei

r stru

ctur

al

feat

ures

.

• D

escr

iptio

n of

way

s of

mod

ifyin

g th

e pr

oper

ties

of p

olym

ers,

incl

udin

g LD

PE

an

d H

DP

E.

• D

educ

tion

of s

truct

ures

of p

olym

ers

form

ed fr

om p

olym

eriz

ing

2-m

ethy

lpro

pene

.

Gui

danc

e:

• Th

e eq

uatio

n fo

r per

cent

ato

m e

cono

my

is p

rovi

ded

in th

e da

ta b

ookl

et in

se

ctio

n 1.

• C

onsi

der o

nly

poly

styr

ene

foam

s as

exa

mpl

es o

f pol

ymer

pro

perty

m

anip

ulat

ion.

Core topics

Chemistry guide114

Esse

ntia

l id

ea:

Che

mic

al t

echn

ique

s po

sitio

n at

oms

in m

olec

ules

usi

ng c

hem

ical

rea

ctio

ns w

hils

t ph

ysic

al t

echn

ique

s al

low

ato

ms/

mol

ecul

es t

o be

man

ipul

ated

and

po

sitio

ned

to s

peci

fic re

quire

men

ts.

A.6

Nan

otec

hnol

ogy

Nat

ure

of s

cien

ce:

Impr

ovem

ents

in a

ppar

atus

—hi

gh p

ower

ele

ctro

n m

icro

scop

es h

ave

allo

wed

for t

he s

tudy

of p

ositi

onin

g of

ato

ms.

(1.8

)

The

need

to re

gard

theo

ries

as u

ncer

tain

—th

e ro

le o

f tria

l and

erro

r in

the

deve

lopm

ent o

f nan

otub

es a

nd th

eir a

ssoc

iate

d th

eorie

s. (2

.2)

“The

prin

cipl

es o

f phy

sics

, as

far a

s I c

an s

ee, d

o no

t spe

ak a

gain

st th

e po

ssib

ility

of m

anoe

uvrin

g th

ings

ato

m b

y at

om. I

t is

not a

n at

tem

pt to

vio

late

any

law

s; it

is

som

ethi

ng, i

n pr

inci

ple,

that

can

be

done

; but

in p

ract

ice,

it h

as n

ot b

een

done

bec

ause

we

are

too

big.

” —

Ric

hard

Fey

nman

, Nob

el P

rize

win

ner i

n P

hysi

cs

Und

erst

andi

ngs:

• M

olec

ular

sel

f-ass

embl

y is

the

botto

m-u

p as

sem

bly

of n

anop

artic

les

and

can

occu

r by

sele

ctiv

ely

atta

chin

g m

olec

ules

to s

peci

fic s

urfa

ces.

Sel

f-ass

embl

y ca

n al

so o

ccur

spo

ntan

eous

ly in

sol

utio

n.

• P

ossi

ble

met

hods

of p

rodu

cing

nan

otub

es a

re a

rc d

isch

arge

, che

mic

al v

apou

r de

posi

tion

(CV

D) a

nd h

igh

pres

sure

car

bon

mon

oxid

e (H

IPC

O).

• A

rc d

isch

arge

invo

lves

eith

er v

apor

izin

g th

e su

rface

of o

ne o

f the

car

bon

elec

trode

s, o

r dis

char

ging

an

arc

thro

ugh

met

al e

lect

rode

s su

bmer

sed

in a

hy

droc

arbo

n so

lven

t, w

hich

form

s a

smal

l rod

-sha

ped

depo

sit o

n th

e an

ode.

App

licat

ions

and

ski

lls:

• D

istin

guis

hing

bet

wee

n ph

ysic

al a

nd c

hem

ical

tech

niqu

es in

man

ipul

atin

g at

oms

to fo

rm m

olec

ules

.

• D

escr

iptio

n of

the

stru

ctur

e an

d pr

oper

ties

of c

arbo

n na

notu

bes.

• E

xpla

natio

n of

why

an

iner

t gas

, and

not

oxy

gen,

is n

eces

sary

for C

VD

pr

epar

atio

n of

car

bon

nano

tube

s.

• E

xpla

natio

n of

the

prod

uctio

n of

car

bon

from

hyd

roca

rbon

sol

vent

s in

arc

di

scha

rge

by o

xida

tion

at th

e an

ode.

• D

educ

tion

of e

quat

ions

for t

he p

rodu

ctio

n of

car

bon

atom

s fro

m H

IPC

O.

Inte

rnat

iona

l-min

dedn

ess:

• S

ome

stud

ies

have

sho

wn

that

inha

ling

nano

parti

cle

dust

can

be

as h

arm

ful a

s as

best

os. S

houl

d na

note

chno

logy

be

regu

late

d or

will

this

hin

der r

esea

rch?

• In

tern

atio

nal c

olla

bora

tion

in s

pace

exp

lora

tion

is g

row

ing.

Wou

ld a

car

bon

nano

tube

spa

ce e

leva

tor b

e fe

asib

le, o

r wan

ted?

Wha

t are

the

impl

icat

ions

?

Theo

ry o

f kno

wle

dge:

• Th

e us

e of

the

scan

ning

tunn

ellin

g m

icro

scop

e ha

s al

low

ed u

s to

“see

” in

divi

dual

ato

ms,

whi

ch w

as p

revi

ousl

y th

ough

t to

be u

natta

inab

le. H

ow d

o th

ese

adva

nces

in te

chno

logy

cha

nge

our v

iew

of w

hat k

now

ledg

e is

at

tain

able

?

• S

ome

peop

le a

re c

once

rned

abo

ut th

e po

ssib

le im

plic

atio

n of

nan

otec

hnol

ogy.

H

ow d

o w

e ev

alua

te th

e po

ssib

le c

onse

quen

ces

of fu

ture

dev

elop

men

ts in

this

ar

ea?

Is th

e kn

owle

dge

we

need

pub

licly

ava

ilabl

e or

do

we

rely

on

the

auth

ority

of e

xper

ts?

Util

izat

ion:

• P

rote

in s

ynth

esis

in c

ells

is a

form

of n

anot

echn

olog

y w

ith ri

boso

mes

act

ing

as

mol

ecul

ar a

ssem

bler

s.

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

cs 4

.3—

mol

ecul

ar p

olar

ity

Core topics

Chemistry guide 115

A.6

Nan

otec

hnol

ogy

• D

iscu

ssio

n of

som

e im

plic

atio

ns a

nd a

pplic

atio

ns o

f nan

otec

hnol

ogy.

• E

xpla

natio

n of

why

nan

otub

es a

re s

trong

and

goo

d co

nduc

tors

of e

lect

ricity

.

Gui

danc

e:

• P

ossi

ble

impl

icat

ions

of n

anot

echn

olog

y in

clud

e un

certa

inty

as

to to

xici

ty le

vels

on

a n

anos

cale

, unk

now

n he

alth

risk

s w

ith n

ew m

ater

ials

, con

cern

that

hum

an

defe

nce

syst

ems

are

not e

ffect

ive

agai

nst p

artic

les

on th

e na

nosc

ale,

re

spon

sibi

litie

s of

the

indu

strie

s an

d go

vern

men

ts in

volv

ed in

this

rese

arch

.

• C

ondu

ctiv

ity o

f gra

phen

e an

d fu

llere

nes

can

be e

xpla

ined

in te

rms

of

delo

caliz

atio

n of

ele

ctro

ns. A

n ex

plan

atio

n ba

sed

on h

ybrid

izat

ion

is n

ot

requ

ired.

Aim

s:

• A

ims

1, 8

and

9: I

nves

tigat

e th

e th

eore

tical

and

larg

e sc

ale

man

ufac

turin

g of

na

note

chno

logy

pro

duct

s an

d th

eir i

mpl

icat

ions

. Exa

mpl

es c

ould

incl

ude

spor

ting

equi

pmen

t, m

edic

inal

pro

duct

s, c

onst

ruct

ion,

env

ironm

enta

l cle

anin

g,

robo

tics,

wea

ponr

y or

oth

er th

eore

tical

com

mer

cial

use

s.

• A

ims

7, 8

and

9: A

nim

atio

ns, s

imul

atio

ns, a

nd v

ideo

s of

nan

otub

e m

anuf

actu

re

and

uses

sho

uld

be u

sed.

Core topics

Chemistry guide116

Esse

ntia

l ide

a: A

lthou

gh m

ater

ials

sci

ence

gen

erat

es m

any

usef

ul n

ew p

rodu

cts

ther

e ar

e ch

alle

nges

ass

ocia

ted

with

recy

clin

g of

and

hig

h le

vels

of t

oxic

ity o

f som

e of

th

ese

mat

eria

ls.

A.7

Env

ironm

enta

l im

pact

—pl

astic

s

Nat

ure

of s

cien

ce:

Ris

ks a

nd p

robl

ems—

scie

ntifi

c re

sear

ch o

ften

proc

eeds

with

per

ceiv

ed b

enef

its in

min

d, b

ut th

e ris

ks a

nd im

plic

atio

ns a

lso

need

to b

e co

nsid

ered

. (4.

8)

Und

erst

andi

ngs:

• P

last

ics

do n

ot d

egra

de e

asily

bec

ause

of t

heir

stro

ng c

oval

ent b

onds

.

• B

urni

ng o

f pol

yvin

yl c

hlor

ide

rele

ases

dio

xins

, HC

l gas

and

inco

mpl

ete

hydr

ocar

bon

com

bust

ion

prod

ucts

.

• D

ioxi

ns c

onta

in u

nsat

urat

ed s

ix-m

embe

r het

eroc

yclic

ring

s w

ith tw

o ox

ygen

at

oms,

usu

ally

in p

ositi

ons

1 an

d 4.

• C

hlor

inat

ed d

ioxi

ns a

re h

orm

one

disr

uptin

g, le

adin

g to

cel

lula

r and

gen

etic

da

mag

e.

• P

last

ics

requ

ire m

ore

proc

essi

ng to

be

recy

cled

than

oth

er m

ater

ials

.

• P

last

ics

are

recy

cled

bas

ed o

n di

ffere

nt re

sin

type

s.

App

licat

ions

and

ski

lls:

• D

educ

tion

of th

e eq

uatio

n fo

r any

giv

en c

ombu

stio

n re

actio

n.

• D

iscu

ssio

n of

why

the

recy

clin

g of

pol

ymer

s is

an

ener

gy in

tens

ive

proc

ess.

• D

iscu

ssio

n of

the

envi

ronm

enta

l im

pact

of t

he u

se o

f pla

stic

s.

• C

ompa

rison

of t

he s

truct

ures

of p

olyc

hlor

inat

ed b

iphe

nyls

(PC

Bs)

and

dio

xins

.

• D

iscu

ssio

n of

the

heal

th c

once

rns

of u

sing

vol

atile

pla

stic

izer

s in

pol

ymer

pr

oduc

tion.

• D

istin

guis

h po

ssib

le R

esin

Iden

tific

atio

n C

odes

(RIC

s) o

f pla

stic

s fro

m a

n IR

sp

ectru

m.

Inte

rnat

iona

l-min

dedn

ess:

• Th

e in

tern

atio

nal s

ymbo

l for

recy

cle,

reus

e an

d re

duce

is a

Mob

ius

strip

de

sign

ed in

the

late

196

0s. H

owev

er, g

loba

l rec

ogni

tion

of th

is s

ymbo

l ran

ks

wel

l bel

ow o

ther

sym

bols

. Wha

t fac

tors

influ

ence

the

reco

gniti

on o

f sym

bols

?

• H

ow c

an n

atio

ns a

ddre

ss th

e pr

oble

m o

f the

pla

stic

gyr

e in

the

Pac

ific

Oce

an?

Theo

ry o

f kno

wle

dge:

• Th

e pr

oduc

ts o

f sci

ence

and

tech

nolo

gy c

an h

ave

a ne

gativ

e im

pact

on

the

envi

ronm

ent.

Are

sci

entis

ts e

thic

ally

resp

onsi

ble

for t

he im

pact

of t

heir

prod

ucts

?

Util

izat

ion:

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 9.

1—re

dox

reac

tions

To

pic

10.1

—or

gani

c co

mpo

unds

To

pic

11.3

—in

frare

d sp

ectro

scop

y B

iolo

gy o

ptio

n C

.3—

impa

ct o

f hum

ans

on e

cosy

stem

s

Aim

s:

• A

im 7

: Dat

abas

e of

RIC

cod

es a

nd IR

spe

ctra

can

be

used

.

• A

im 8

: The

dev

elop

men

t of g

reen

che

mis

try h

as ra

ised

the

awar

enes

s of

the

envi

ronm

enta

l and

the

ethi

cal i

mpl

icat

ions

of u

sing

sci

ence

and

tech

nolo

gy.

Core topics

Chemistry guide 117

A.7

Env

ironm

enta

l im

pact

—pl

astic

s

Gui

danc

e:

• D

ioxi

ns d

o no

t dec

ompo

se in

the

envi

ronm

ent a

nd c

an b

e pa

ssed

on

in th

e fo

od c

hain

.

• C

onsi

der p

olyc

hlor

inat

ed d

iben

zodi

oxin

s (P

CD

D) a

nd P

CB

s as

exa

mpl

es o

f ca

rcin

ogen

ic c

hlor

inat

ed d

ioxi

ns o

r dio

xin-

like

subs

tanc

es.

• C

onsi

der p

htha

late

est

ers

as e

xam

ples

of p

last

iciz

ers.

• H

ouse

fire

s ca

n re

leas

e m

any

toxi

ns d

ue to

pla

stic

s (s

how

er c

urta

ins,

etc

). Lo

w

smok

e ze

ro h

alog

en c

ablin

g is

ofte

n us

ed in

wiri

ng to

pre

vent

thes

e ha

zard

s.

• R

esin

Iden

tific

atio

n C

odes

(RIC

s) a

re in

the

data

boo

klet

in s

ectio

n 30

.

• S

truct

ures

of v

ario

us m

ater

ials

mol

ecul

es a

re in

the

data

boo

klet

in s

ectio

n 31

.

Additonal higher level topics

Chemistry guide118

Esse

ntia

l ide

a: S

uper

cond

uctiv

ity is

zer

o el

ectri

cal r

esis

tanc

e an

d ex

puls

ion

of m

agne

tic fi

elds

. X-ra

y cr

ysta

llogr

aphy

can

be

used

to a

naly

se s

truct

ures

.

A.8

Sup

erco

nduc

ting

met

als

and

X-ra

y cr

ysta

llogr

aphy

Nat

ure

of s

cien

ce:

Impo

rtanc

e of

theo

ries—

supe

rcon

duct

ing

mat

eria

ls, w

ith z

ero

elec

trica

l res

ista

nce

belo

w a

cer

tain

tem

pera

ture

, pro

vide

a g

ood

exam

ple

of th

eorie

s ne

edin

g to

be

mod

ified

to

fit n

ew d

ata.

It is

impo

rtant

to u

nder

stan

d th

e ba

sic

scie

ntifi

c pr

inci

ples

beh

ind

mod

ern

inst

rum

ents

. (2.

2)

Und

erst

andi

ngs:

• S

uper

cond

ucto

rs a

re m

ater

ials

that

offe

r no

resi

stan

ce to

ele

ctric

cur

rent

s be

low

a c

ritic

al te

mpe

ratu

re.

• Th

e M

eiss

ner e

ffect

is th

e ab

ility

of a

sup

erco

nduc

tor t

o cr

eate

a m

irror

imag

e m

agne

tic fi

eld

of a

n ex

tern

al fi

eld,

thus

exp

ellin

g it.

• R

esis

tanc

e in

met

allic

con

duct

ors

is c

ause

d by

col

lisio

ns b

etw

een

elec

trons

an

d po

sitiv

e io

ns o

f the

latti

ce.

• Th

e B

arde

en–C

oope

r–S

chrie

ffer (

BC

S) t

heor

y ex

plai

ns th

at b

elow

the

criti

cal

tem

pera

ture

ele

ctro

ns in

sup

erco

nduc

tors

form

Coo

per p

airs

whi

ch m

ove

freel

y th

roug

h th

e su

perc

ondu

ctor

.

• Ty

pe 1

sup

erco

nduc

tors

hav

e sh

arp

trans

ition

s to

sup

erco

nduc

tivity

whe

reas

Ty

pe 2

sup

erco

nduc

tors

hav

e m

ore

grad

ual t

rans

ition

s.

• X-

ray

diffr

actio

n ca

n be

use

d to

ana

lyse

stru

ctur

es o

f met

allic

and

ioni

c co

mpo

unds

.

• C

ryst

al la

ttice

s co

ntai

n si

mpl

e re

peat

ing

unit

cells

.

• A

tom

s on

face

s an

d ed

ges

of u

nit c

ells

are

sha

red.

• Th

e nu

mbe

r of n

eare

st n

eigh

bour

s of

an

atom

/ion

is it

s co

ordi

natio

n nu

mbe

r.

Inte

rnat

iona

l-min

dedn

ess:

• A

naly

tical

tech

niqu

es h

ave

appl

icat

ions

in fo

rens

ics,

min

eral

exp

lora

tion,

m

edic

ine

and

else

whe

re. H

ow d

oes

the

uneq

ual a

cces

s to

adv

ance

d te

chno

logy

affe

ct w

orld

eco

nom

ies?

Theo

ry o

f kno

wle

dge:

• X-

ray

diffr

actio

n ha

s al

low

ed u

s to

pro

be th

e w

orld

bey

ond

the

biol

ogic

al li

mits

of

our

sen

ses.

How

relia

ble

is o

ur k

now

ledg

e of

the

mic

rosc

opic

wor

ld

com

pare

d to

wha

t we

know

at t

he m

acro

scop

ic le

vel?

Util

izat

ion:

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 2.

2—P

auli

excl

usio

n pr

inci

ple

Topi

c 3.

2—at

omic

radi

us a

nd p

erio

dici

ty

Topi

c 21

.1—

X-ra

y cr

ysta

llogr

aphy

P

hysi

cs to

pic

4.2—

trave

lling

wav

es

Aim

s:

• A

im 7

: Ani

mat

ions

and

sim

ulat

ions

wou

ld b

e ve

ry u

sefu

l to

expl

ain

supe

rcon

duct

ivity

and

X-ra

y cr

ysta

llogr

aphy

.

Addi

tiona

l hig

her l

evel

topi

cs

Opt

ion

A:

Mat

eria

ls

15/2

5 ho

urs


Chemistry guide 119

A.8

Sup

erco

nduc

ting

met

als

and

X-ra

y cr

ysta

llogr

aphy

App

licat

ions

and

ski

lls:

• A

naly

sis

of re

sist

ance

ver

sus

tem

pera

ture

dat

a fo

r Typ

e 1

and

Type

2

supe

rcon

duct

ors.

• E

xpla

natio

n of

sup

erco

nduc

tivity

in te

rms

of C

oope

r pai

rs m

ovin

g th

roug

h a

posi

tive

ion

latti

ce.

• D

educ

tion

or c

onst

ruct

ion

of u

nit c

ell s

truct

ures

from

cry

stal

stru

ctur

e in

form

atio

n.

• A

pplic

atio

n of

the

Bra

gg e

quat

ion,

𝑛𝑛𝑛𝑛

=2𝑑𝑑

𝑑𝑑𝑑𝑑𝑛𝑛𝑑𝑑,

in m

etal

lic s

truct

ures

.

• D

eter

min

atio

n of

the

dens

ity o

f a p

ure

met

al fr

om it

s at

omic

radi

i and

cry

stal

pa

ckin

g st

ruct

ure.

Gui

danc

e:

• O

nly

a si

mpl

e ex

plan

atio

n of

BC

S th

eory

with

Coo

per p

airs

is re

quire

d. A

t low

te

mpe

ratu

res

the

posi

tive

ions

in th

e la

ttice

are

dis

torte

d sl

ight

ly b

y a

pass

ing

elec

tron.

A s

econ

d el

ectro

n is

attr

acte

d to

this

slig

ht p

ositi

ve d

efor

mat

ion

and

a co

uplin

g of

thes

e tw

o el

ectro

ns o

ccur

s.

• O

pera

ting

prin

cipl

es o

f X-ra

y cr

ysta

llogr

aphy

are

not

requ

ired.

• O

nly

pure

met

als

with

sim

ple

cubi

c ce

lls, b

ody

cent

red

cubi

c ce

lls (B

CC

) and

fa

ce c

entre

d cu

bic

cells

(FC

C) s

houl

d be

cov

ered

.

• P

erov

skite

cry

stal

line

stru

ctur

es o

f man

y su

perc

ondu

ctor

s ca

n be

ana

lyse

d by

X-

ray

crys

tallo

grap

hy b

ut th

ese

will

not

be

asse

ssed

.

• B

ragg

's e

quat

ion

will

onl

y be

app

lied

to s

impl

e cu

bic

stru

ctur

es.


Chemistry guide120

Esse

ntia

l ide

a: C

onde

nsat

ion

poly

mer

s ar

e fo

rmed

by

the

loss

of s

mal

l mol

ecul

es a

s fu

nctio

nal g

roup

s fro

m m

onom

ers

join

.

A.9

Con

dens

atio

n po

lym

ers

Nat

ure

of s

cien

ce:

Spe

cula

tion—

we

have

had

the

Sto

ne A

ge, I

ron

Age

and

Bro

nze

Age

. Is

it po

ssib

le th

at to

day’

s ag

e is

the

Age

of P

olym

ers,

as

scie

nce

cont

inue

s to

man

ipul

ate

mat

ter f

or

desi

red

purp

oses

? (1

.5)

Und

erst

andi

ngs:

• C

onde

nsat

ion

poly

mer

s re

quire

two

func

tiona

l gro

ups

on e

ach

mon

omer

.

• N

H3,

HC

l and

H2O

are

pos

sibl

e pr

oduc

ts o

f con

dens

atio

n re

actio

ns.

• K

evla

r® is

a p

olya

mid

e w

ith a

stro

ng a

nd o

rder

ed s

truct

ure.

The

hyd

roge

n bo

nds

betw

een

O a

nd N

can

be

brok

en w

ith th

e us

e of

con

cent

rate

d su

lfuric

ac

id.

App

licat

ions

and

ski

lls:

• D

istin

guis

hing

bet

wee

n ad

ditio

n an

d co

nden

satio

n po

lym

ers.

• C

ompl

etio

n an

d de

scrip

tions

of e

quat

ions

to s

how

how

con

dens

atio

n po

lym

ers

are

form

ed.

• D

educ

tion

of th

e st

ruct

ures

of p

olya

mid

es a

nd p

olye

ster

s fro

m th

eir r

espe

ctiv

e m

onom

ers.

• E

xpla

natio

n of

Kev

lar®

’s s

treng

th a

nd it

s so

lubi

lity

in c

once

ntra

ted

sulfu

ric a

cid.

Gui

danc

e:

• C

onsi

der g

reen

che

mis

try p

olym

ers.

Inte

rnat

iona

l-min

dedn

ess:

• D

oes

scie

nce,

eco

nom

ics

or p

oliti

cs p

lay

the

mos

t ess

entia

l rol

e in

rese

arch

, su

ch a

s th

e de

velo

pmen

t of n

ew p

olym

ers?

Util

izat

ion:

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 10

.2—

addi

tion

and

cond

ensa

tion

reac

tions

To

pic

20.2

—sy

nthe

sis

tech

niqu

es

Opt

ion

A.5

—po

lym

ers

Aim

s:

• A

im 6

: Syn

thes

is o

f nyl

on c

ould

be

perfo

rmed

.


Chemistry guide 121

Esse

ntia

l ide

a: T

oxic

ity a

nd c

arci

noge

nic

prop

ertie

s of

hea

vy m

etal

s ar

e th

e re

sult

of th

eir a

bilit

y to

form

coo

rdin

ated

com

poun

ds, h

ave

vario

us o

xida

tion

stat

es a

nd a

ct a

s ca

taly

sts

in th

e hu

man

bod

y.

A.1

0 En

viro

nmen

tal i

mpa

ct—

heav

y m

etal

s

Nat

ure

of s

cien

ce:

Ris

ks a

nd p

robl

ems—

scie

ntifi

c re

sear

ch o

ften

proc

eeds

with

per

ceiv

ed b

enef

its in

min

d, b

ut th

e ris

ks a

nd im

plic

atio

ns a

lso

need

to b

e co

nsid

ered

. (4.

8)

Und

erst

andi

ngs:

• To

xic

dose

s of

tran

sitio

n m

etal

s ca

n di

stur

b th

e no

rmal

oxi

datio

n/re

duct

ion

bala

nce

in c

ells

thro

ugh

vario

us m

echa

nism

s.

• So

me

met

hods

of r

emov

ing

heav

y m

etal

s ar

e pr

ecip

itatio

n, a

dsor

ptio

n, a

nd c

hela

tion.

• P

olyd

enta

te li

gand

s fo

rm m

ore

stab

le c

ompl

exes

than

sim

ilar m

onod

enta

te

ligan

ds d

ue to

the

chel

ate

effe

ct, w

hich

can

be

expl

aine

d by

con

side

ring

entro

py c

hang

es.

App

licat

ions

and

ski

lls:

• E

xpla

natio

n of

how

che

latin

g su

bsta

nces

can

be

used

to re

mov

e he

avy

met

als.

• D

educ

tion

of th

e nu

mbe

r of c

oord

inat

e bo

nds

a lig

and

can

form

with

a c

entra

l m

etal

ion.

• C

alcu

latio

ns in

volv

ing

Ksp

as

an a

pplic

atio

n of

rem

ovin

g m

etal

s in

sol

utio

n.

• C

ompa

re a

nd c

ontra

st th

e Fe

nton

and

Hab

er–W

eiss

reac

tion

mec

hani

sm.

Gui

danc

e:

• E

than

e-1,

2-di

amin

e ac

ts a

s a

bide

ntat

e lig

and

and

ED

TA4-

act

s as

hex

aden

tate

lig

and.

• Th

e H

aber

–Wei

ss re

actio

n ge

nera

tes

free

radi

cals

nat

ural

ly in

bio

logi

cal

proc

esse

s. T

rans

ition

met

als

can

cata

lyse

the

reac

tion

with

the

iron-

cata

lyse

d (F

ento

n) re

actio

n be

ing

the

mec

hani

sm fo

r gen

erat

ing

reac

tive

hydr

oxyl

ra

dica

ls.

• K

sp v

alue

s ar

e in

the

data

boo

klet

in s

ectio

n 32

.

Theo

ry o

f kno

wle

dge:

• W

hat r

espo

nsib

ility

do

scie

ntis

ts h

ave

for t

he im

pact

of t

heir

ende

avou

rs o

n th

e pl

anet

?

Util

izat

ion:

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 9.

1—re

dox

reac

tions

To

pic

13.2

—tra

nsiti

on m

etal

com

plex

es

Bio

logy

opt

ion

C.3

—im

pact

of h

uman

s on

eco

syst

ems

Aim

s:

• A

ims

1 an

d 8:

Inve

stig

atio

ns o

f was

te w

ater

trea

tmen

t.

• A

im 6

: Exp

erim

ents

cou

ld in

clud

e in

vest

igat

ions

of K

sp.

Core topics

Chemistry guide122

Esse

ntia

l ide

a: M

etab

olic

reac

tions

invo

lve

a co

mpl

ex in

terp

lay

betw

een

man

y di

ffere

nt c

ompo

nent

s in

hig

hly

cont

rolle

d en

viro

nmen

ts.

B.1

Intr

oduc

tion

to b

ioch

emis

try

Nat

ure

of s

cien

ce:

Use

of d

ata—

bioc

hem

ical

sys

tem

s ha

ve a

larg

e nu

mbe

r of d

iffer

ent r

eact

ions

occ

urrin

g in

the

sam

e pl

ace

at th

e sa

me

time.

As

tech

nolo

gies

hav

e de

velo

ped,

mor

e da

ta h

as

been

col

lect

ed le

adin

g to

the

disc

over

y of

pat

tern

s of

reac

tions

in m

etab

olis

m. (

3.1)

Und

erst

andi

ngs:

• Th

e di

vers

e fu

nctio

ns o

f bio

logi

cal m

olec

ules

dep

end

on th

eir s

truct

ures

and

sh

apes

.

• M

etab

olic

reac

tions

take

pla

ce in

hig

hly

cont

rolle

d aq

ueou

s en

viro

nmen

ts.

• R

eact

ions

of b

reak

dow

n ar

e ca

lled

cata

bolis

m a

nd re

actio

ns o

f syn

thes

is a

re

calle

d an

abol

ism

.

• B

iopo

lym

ers

form

by

cond

ensa

tion

reac

tions

and

are

bro

ken

dow

n by

hy

drol

ysis

reac

tions

.

• P

hoto

synt

hesi

s is

the

synt

hesi

s of

ene

rgy-

rich

mol

ecul

es fr

om c

arbo

n di

oxid

e an

d w

ater

usi

ng li

ght e

nerg

y.

• R

espi

ratio

n is

a c

ompl

ex s

et o

f met

abol

ic p

roce

sses

pro

vidi

ng e

nerg

y fo

r cel

ls.

App

licat

ions

and

ski

lls :

• E

xpla

natio

n of

the

diffe

renc

e be

twee

n co

nden

satio

n an

d hy

drol

ysis

reac

tions

.

• Th

e us

e of

sum

mar

y eq

uatio

ns o

f pho

tosy

nthe

sis

and

resp

iratio

n to

exp

lain

the

pote

ntia

l bal

anci

ng o

f oxy

gen

and

carb

on d

ioxi

de in

the

atm

osph

ere.

Gui

danc

e:

• In

term

edia

tes

of a

erob

ic re

spira

tion

and

phot

osyn

thes

is a

re n

ot re

quire

d.

Inte

rnat

iona

l-min

dedn

ess:

• M

etab

olic

reac

tions

in th

e hu

man

bod

y ar

e de

pend

ent o

n th

e su

pply

of

nutri

ents

thro

ugh

a re

gula

r bal

ance

d di

et. G

loba

lly th

ere

are

sign

ifica

nt

diffe

renc

es in

the

avai

labi

lity

of n

utrit

ious

food

, whi

ch h

ave

maj

or a

nd d

iver

se

impa

cts

on h

uman

hea

lth.

Util

izat

ion:

• B

ioch

emis

try is

fund

amen

tal t

o th

e st

udy

of m

any

othe

r sub

ject

s, in

clud

ing

gene

tics,

imm

unol

ogy,

pha

rmac

olog

y, n

utrit

ion

and

agric

ultu

re.

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 10

.2—

SN re

actio

ns (c

onde

nsat

ion

and

hydr

olys

is)

Topi

c 13

.2 a

nd O

ptio

n B

.9—

met

al c

ompl

exes

and

ligh

t abs

orpt

ion

Opt

ion

C.8

—el

ectro

nic

conj

ugat

ion

and

ligh

t abs

orpt

ion

Core

topi

cs

Opt

ion

B: B

ioch

emis

try

15/2

5 ho

urs

Core topics

Chemistry guide 123

Esse

ntia

l ide

a: P

rote

ins

are

the

mos

t div

erse

of t

he b

iopo

lym

ers

resp

onsi

ble

for m

etab

olis

m a

nd s

truct

ural

inte

grity

of l

ivin

g or

gani

sms.

B.2

Pro

tein

s an

d en

zym

es

Nat

ure

of s

cien

ce:

Col

labo

ratio

n an

d pe

er re

view

—se

vera

l diff

eren

t exp

erim

ents

on

seve

ral c

ontin

ents

led

to th

e co

nclu

sion

that

DN

A, a

nd n

ot p

rote

in a

s or

igin

ally

thou

ght,

carri

ed th

e in

form

atio

n fo

r inh

erita

nce.

(4.4

)

Und

erst

andi

ngs:

• P

rote

ins

are

poly

mer

s of

2-a

min

o ac

ids,

join

ed b

y am

ide

links

(als

o kn

own

as

pept

ide

bond

s).

• A

min

o ac

ids

are

amph

oter

ic a

nd c

an e

xist

as

zwitt

erio

ns, c

atio

ns a

nd a

nion

s.

• P

rote

in s

truct

ures

are

div

erse

and

are

des

crib

ed a

t the

prim

ary,

sec

onda

ry,

terti

ary

and

quat

erna

ry le

vels

.

• A

pro

tein

’s th

ree-

dim

ensi

onal

sha

pe d

eter

min

es it

s ro

le in

stru

ctur

al

com

pone

nts

or in

met

abol

ic p

roce

sses

.

• M

ost e

nzym

es a

re p

rote

ins

that

act

as

cata

lyst

s by

bin

ding

spe

cific

ally

to a

su

bstra

te a

t the

act

ive

site

.

• A

s en

zym

e ac

tivity

dep

ends

on

the

conf

orm

atio

n, it

is s

ensi

tive

to c

hang

es in

te

mpe

ratu

re a

nd p

H a

nd th

e pr

esen

ce o

f hea

vy m

etal

ions

.

• C

hrom

atog

raph

y se

para

tion

is b

ased

on

diffe

rent

phy

sica

l and

che

mic

al

prin

cipl

es.

App

licat

ions

and

ski

lls:

• D

educ

tion

of th

e st

ruct

ural

form

ulas

of r

eact

ants

and

pro

duct

s in

con

dens

atio

n re

actio

ns o

f am

ino

acid

s, a

nd h

ydro

lysi

s re

actio

ns o

f pep

tides

.

• E

xpla

natio

n of

the

solu

bilit

ies

and

mel

ting

poin

ts o

f am

ino

acid

s in

term

s of

zw

itter

ions

.

• A

pplic

atio

n of

the

rela

tions

hips

bet

wee

n ch

arge

, pH

and

isoe

lect

ric p

oint

for

amin

o ac

ids

and

prot

eins

.

Inte

rnat

iona

l-min

dedn

ess:

• Th

e U

nive

rsal

Pro

tein

Res

ourc

e (U

niP

rot)

is a

con

sorti

um o

f bio

info

rmat

ics

inst

itute

s. It

s m

issi

on is

to a

ct a

s a

reso

urce

for t

he s

cien

tific

com

mun

ity b

y pr

ovid

ing

com

preh

ensi

ve, h

igh-

qual

ity a

nd fr

eely

acc

essi

ble

data

on

prot

ein

sequ

ence

and

func

tiona

l inf

orm

atio

n.

Util

izat

ion:

• M

any

synt

hetic

mat

eria

ls a

re p

olya

mid

es. E

xam

ples

incl

ude

nylo

n an

d K

evla

r®.

• E

lect

roph

ores

is is

use

d in

som

e m

edic

al d

iagn

ostic

s to

iden

tify

patte

rns

of

unus

ual p

rote

in c

onte

nt in

blo

od s

erum

or u

rine.

• Th

e fir

st p

rote

in to

be

sequ

ence

d w

as in

sulin

by

Fred

eric

k S

ange

r in

1951

, in

a pr

oces

s th

at to

ok o

ver t

en y

ears

. Tod

ay, p

rote

in s

eque

ncin

g is

a ro

utin

e an

d ve

ry e

ffici

ent p

roce

ss, a

nd is

a m

ajor

par

t of t

he s

tudy

kno

wn

as p

rote

omic

s.

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

cs 8

.3 a

nd 1

8.2—

pH a

nd p

Ka a

nd p

Kb v

alue

s To

pic

20.3

—st

ereo

isom

eris

m

Opt

ion

A.9

—co

nden

satio

n po

lym

ers

Opt

ion

B.9

—ch

rom

atog

raph

y B

iolo

gy to

pics

2.4

, 2.5

and

8.1

—pr

otei

ns a

nd e

nzym

es

Aim

s:

• A

im 6

: Exp

erim

ents

cou

ld in

volv

e hy

drol

ysis

of a

pro

tein

, sep

arat

ion

and

iden

tific

atio

n of

am

ino

acid

mix

ture

s by

pap

er c

hrom

atog

raph

y, o

r gel

el

ectro

phor

esis

of p

rote

ins

and

DN

A.

• A

im 7

: Dat

a lo

ggin

g ex

perim

ents

invo

lvin

g ab

sorp

tion/

conc

entra

tion

stud

ies

for

prot

ein

cont

ent u

sing

the

Biu

ret r

eage

nt.

Core topics

Chemistry guide124

B.2

Pro

tein

s an

d en

zym

es

• D

escr

iptio

n of

the

four

leve

ls o

f pro

tein

stru

ctur

e, in

clud

ing

the

orig

in a

nd ty

pes

of b

onds

and

inte

ract

ions

invo

lved

.

• D

educ

tion

and

inte

rpre

tatio

n of

gra

phs

of e

nzym

e ac

tivity

invo

lvin

g ch

ange

s in

su

bstra

te c

once

ntra

tion,

pH

and

tem

pera

ture

.

• E

xpla

natio

n of

the

proc

esse

s of

pap

er c

hrom

atog

raph

y an

d ge

l ele

ctro

phor

esis

in

am

ino

acid

and

pro

tein

sep

arat

ion

and

iden

tific

atio

n.

Gui

danc

e:

• Th

e na

mes

and

stru

ctur

al fo

rmul

as o

f the

am

ino

acid

s ar

e gi

ven

in th

e da

ta

book

let i

n se

ctio

n 33

.

• R

efer

ence

sho

uld

be m

ade

to a

lpha

hel

ix a

nd b

eta

plea

ted

shee

t, an

d to

fib

rous

and

glo

bula

r pro

tein

s w

ith e

xam

ples

of e

ach.

• In

pap

er c

hrom

atog

raph

y th

e us

e of

Rf v

alue

s an

d lo

catin

g ag

ents

sho

uld

be

cove

red.

• In

enz

yme

kine

tics

Km a

nd V

max

are

not

requ

ired.

• A

im 7

: Sim

ulat

ions

can

be

used

for g

el e

lect

roph

ores

is.

Core topics

Chemistry guide 125

Esse

ntia

l ide

a: L

ipid

s ar

e a

broa

d gr

oup

of b

iom

olec

ules

that

are

larg

ely

non-

pola

r and

ther

efor

e in

solu

ble

in w

ater

.

B.3

Lip

ids

Nat

ure

of s

cien

ce:

Sig

nific

ance

of s

cien

ce e

xpla

natio

ns to

the

publ

ic—

long

-term

stu

dies

hav

e le

d to

kno

wle

dge

of th

e ne

gativ

e ef

fect

s of

die

ts h

igh

in s

atur

ated

fat,

chol

este

rol,

and

trans

-fat.

This

has

led

to n

ew fo

od p

rodu

cts.

(5.2

)

Und

erst

andi

ngs:

• Fa

ts a

re m

ore

redu

ced

than

car

bohy

drat

es a

nd s

o yi

eld

mor

e en

ergy

whe

n ox

idiz

ed.

• Tr

igly

cerid

es a

re p

rodu

ced

by c

onde

nsat

ion

of g

lyce

rol w

ith th

ree

fatty

aci

ds

and

cont

ain

este

r lin

ks. F

atty

aci

ds c

an b

e sa

tura

ted,

mon

ouns

atur

ated

or

poly

unsa

tura

ted.

• P

hosp

holip

ids

are

deriv

ativ

es o

f trig

lyce

rides

.

• H

ydro

lysi

s of

trig

lyce

rides

and

pho

spho

lipid

s ca

n oc

cur u

sing

enz

ymes

or i

n al

kalin

e or

aci

dic

cond

ition

s.

• S

tero

ids

have

a c

hara

cter

istic

fuse

d rin

g st

ruct

ure,

kno

wn

as a

ste

roid

al

back

bone

.

• Li

pids

act

as

stru

ctur

al c

ompo

nent

s of

cel

l mem

bran

es, i

n en

ergy

sto

rage

, th

erm

al a

nd e

lect

rical

insu

latio

n, a

s tra

nspo

rters

of l

ipid

sol

uble

vita

min

s an

d as

ho

rmon

es.

App

licat

ions

and

ski

lls:

• D

educ

tion

of th

e st

ruct

ural

form

ulas

of r

eact

ants

and

pro

duct

s in

con

dens

atio

n an

d hy

drol

ysis

reac

tions

bet

wee

n gl

ycer

ol a

nd fa

tty a

cids

and

/or p

hosp

hate

.

• P

redi

ctio

n of

the

rela

tive

mel

ting

poin

ts o

f fat

s an

d oi

ls fr

om th

eir s

truct

ures

.

• C

ompa

rison

of t

he p

roce

sses

of h

ydro

lytic

and

oxi

dativ

e ra

ncid

ity in

fats

with

re

spec

t to

the

site

of r

eact

ivity

in th

e m

olec

ules

and

the

cond

ition

s th

at fa

vour

th

e re

actio

n.

Inte

rnat

iona

l-min

dedn

ess:

• Th

ere

are

larg

e gl

obal

and

cul

tura

l diff

eren

ces

in th

e di

etar

y so

urce

s of

lipi

ds

and

met

hods

use

d to

pre

vent

ranc

idity

.

Theo

ry o

f kno

wle

dge:

• D

iffer

ent c

ount

ries

have

ver

y di

ffere

nt s

tand

ards

tow

ards

food

labe

lling

. Is

acce

ss to

info

rmat

ion

a hu

man

righ

t? W

hat k

now

ledg

e sh

ould

be

univ

ersa

lly

avai

labl

e?

• W

hat a

re th

e di

ffere

nt re

spon

sibi

litie

s of

gov

ernm

ent,

indu

stry

, the

med

ical

pr

ofes

sion

and

the

indi

vidu

al in

mak

ing

heal

thy

choi

ces

abou

t die

t? P

ublic

bo

dies

can

pro

tect

the

indi

vidu

al b

ut a

lso

limit

thei

r fre

edom

. How

do

we

know

w

hat i

s be

st fo

r soc

iety

and

the

indi

vidu

al?

Util

izat

ion:

• A

lkal

ine

hydr

olys

is o

f fat

s is

use

d in

the

proc

ess

of s

oap-

mak

ing,

kno

wn

as

sapo

nific

atio

n.

• S

tero

id a

buse

, esp

ecia

lly in

spo

rts, a

nd m

etho

ds fo

r det

ectio

n.

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

cs 1

0.1

and

10.2

—fu

nctio

nal g

roup

s, h

ydro

gena

tion

of a

lken

es

Topi

c 10

.2—

free

radi

cal m

echa

nism

s To

pic

20.3

—co

nfig

urat

iona

l iso

mer

ism

B

iolo

gy to

pic

2.3—

lipid

s

Core topics

Chemistry guide126

B.3

Lip

ids

• A

pplic

atio

n of

the

conc

ept o

f iod

ine

num

ber t

o de

term

ine

the

unsa

tura

tion

of a

fa

t.

• C

ompa

rison

of c

arbo

hydr

ates

and

lipi

ds a

s en

ergy

sto

rage

mol

ecul

es w

ith

resp

ect t

o th

eir s

olub

ility

and

ene

rgy

dens

ity.

• D

iscu

ssio

n of

the

impa

ct o

f lip

ids

on h

ealth

, inc

ludi

ng th

e ro

les

of d

ieta

ry h

igh-

dens

ity li

popr

otei

n (H

DL)

and

low

-den

sity

lipo

prot

ein

(LD

L) c

hole

ster

ol,

satu

rate

d, u

nsat

urat

ed a

nd tr

ans-

fat a

nd th

e us

e an

d ab

use

of s

tero

ids.

Gui

danc

e:

• Th

e st

ruct

ures

of s

ome

fatty

aci

ds a

re g

iven

in th

e da

ta b

ookl

et in

sec

tion

34.

• S

peci

fic n

amed

exa

mpl

es o

f fat

s an

d oi

ls d

o no

t hav

e to

be

lear

ned.

• Th

e st

ruct

ural

diff

eren

ces

betw

een

cis-

and

tran

s-fa

ts a

re n

ot re

quire

d.

Aim

s:

• A

im 6

: Exp

erim

ents

cou

ld in

clud

e th

e ca

lcul

atio

n of

the

iodi

ne n

umbe

r of f

ats

to

mea

sure

deg

ree

of u

nsat

urat

ion,

cal

orim

etric

exp

erim

ents

on

diffe

rent

fats

and

oi

ls, o

r the

sep

arat

ion

of li

pids

from

com

mon

food

sou

rces

usi

ng d

iffer

ent

solv

ents

and

a s

epar

atin

g fu

nnel

.

Core topics

Chemistry guide 127

Esse

ntia

l ide

a: C

arbo

hydr

ates

are

oxy

gen-

rich

biom

olec

ules

, whi

ch p

lay

a ce

ntra

l rol

e in

met

abol

ic re

actio

ns o

f ene

rgy

trans

fer.

B.4

Car

bohy

drat

es

Nat

ure

of s

cien

ce:

Con

stru

ct m

odel

s/vi

sual

izat

ions

—un

ders

tand

ing

the

ster

eoch

emis

try o

f car

bohy

drat

es is

ess

entia

l to

unde

rsta

ndin

g th

eir s

truct

ural

role

s in

cel

ls. H

awor

th p

roje

ctio

ns h

elp

focu

s on

the

natu

re a

nd p

ositi

on o

f atta

ched

gro

ups

by m

akin

g ca

rbon

and

hyd

roge

n im

plic

it. (1

.10)

Obt

aini

ng e

vide

nce

for s

cien

tific

theo

ries—

cons

ider

the

stru

ctur

al ro

le o

f car

bohy

drat

es. (

1.8)

Und

erst

andi

ngs:

• C

arbo

hydr

ates

hav

e th

e ge

nera

l for

mul

a C

x(H2O

) y.

• H

awor

th p

roje

ctio

ns re

pres

ent t

he c

yclic

stru

ctur

es o

f mon

osac

char

ides

.

• M

onos

acch

arid

es c

onta

in e

ither

an

alde

hyde

gro

up (a

ldos

e) o

r a k

eton

e gr

oup

(ket

ose)

and

sev

eral

–O

H g

roup

s.

• S

traig

ht c

hain

form

s of

sug

ars

cycl

ize

in s

olut

ion

to fo

rm ri

ng s

truct

ures

co

ntai

ning

an

ethe

r lin

kage

.

• G

lyco

sidi

c bo

nds

form

bet

wee

n m

onos

acch

arid

es fo

rmin

g di

sacc

harid

es a

nd

poly

sacc

harid

es.

• C

arbo

hydr

ates

are

use

d as

ene

rgy

sour

ces

and

ener

gy re

serv

es.

App

licat

ions

and

ski

lls:

• D

educ

tion

of th

e st

ruct

ural

form

ulas

of d

isac

char

ides

and

pol

ysac

char

ides

from

gi

ven

mon

osac

char

ides

.

• R

elat

ions

hip

of th

e pr

oper

ties

and

func

tions

of m

onos

acch

arid

es a

nd

poly

sacc

harid

es to

thei

r che

mic

al s

truct

ures

.

Inte

rnat

iona

l-min

dedn

ess:

• S

ugar

is a

maj

or in

tern

atio

nal c

omm

odity

and

is p

rodu

ced

in a

bout

130

diff

eren

t co

untri

es. A

ppro

xim

atel

y th

ree-

quar

ters

of p

rodu

ctio

n co

mes

from

sug

ar c

ane

in tr

opic

al a

nd s

ubtro

pica

l reg

ions

and

the

rem

aind

er c

omes

from

sug

ar b

eet

whi

ch is

cul

tivat

ed in

tem

pera

te c

limat

es.

• D

iabe

tes

is a

chr

onic

dis

ease

that

occ

urs

whe

n th

e bo

dy c

anno

t effe

ctiv

ely

regu

late

blo

od s

ugar

, due

to a

failu

re in

the

prod

uctio

n or

func

tioni

ng o

f ins

ulin

. Th

e W

orld

Hea

lth O

rgan

izat

ion

proj

ects

that

dea

ths

from

dia

bete

s w

ill d

oubl

e be

twee

n 20

05 a

nd 2

030.

• La

ctos

e in

tole

ranc

e is

a c

ondi

tion

in w

hich

the

indi

vidu

al is

not

abl

e to

dig

est

lact

ose,

the

suga

r fou

nd in

milk

and

dai

ry p

rodu

cts.

It is

due

to a

failu

re to

pr

oduc

e su

ffici

ent l

evel

s of

lact

ase,

the

enzy

me

that

hyd

roly

ses

lact

ose

into

gl

ucos

e an

d ga

lact

ose.

Glo

bally

lact

ose

into

lera

nce

is th

e no

rm. I

t is

an

exam

ple

of a

Wes

tern

per

spec

tive

inva

ding

sci

ence

.

Theo

ry o

f kno

wle

dge:

• Th

e us

e of

asp

arta

me

as a

n ar

tific

ial s

wee

tene

r has

bee

n co

ntro

vers

ial f

or

man

y ye

ars

as th

e si

de e

ffect

s ar

e no

t ful

ly in

vest

igat

ed. S

houl

d sc

ient

ists

be

held

mor

ally

resp

onsi

ble

for t

he a

dver

se c

onse

quen

ces

of th

eir w

ork?

Core topics

Chemistry guide128

B.4

Car

bohy

drat

es

Gui

danc

e:

• Th

e st

raig

ht c

hain

and

α-ri

ng fo

rms

of g

luco

se a

nd fr

ucto

se a

re g

iven

in th

e da

ta b

ookl

et in

sec

tion

34.

• Th

e co

mpo

nent

mon

osac

char

ides

of s

peci

fic d

isac

char

ides

and

the

linka

ge

deta

ils o

f pol

ysac

char

ides

are

not

requ

ired.

• Th

e di

stin

ctio

n be

twee

n

- and

- f

orm

s an

d th

e st

ruct

ure

of c

ellu

lose

are

not

re

quire

d.

Util

izat

ion:

• C

arbo

hydr

ates

are

use

d in

the

phar

mac

eutic

al in

dust

ry to

bin

d pr

epar

atio

ns

into

tabl

ets.

• E

than

ol is

pro

duce

d as

a b

iofu

el fr

om th

e fe

rmen

tatio

n of

car

bohy

drat

es in

cr

ops

such

as

corn

or s

ugar

can

e.

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

cs 1

0.1

and

10.2

—or

gani

c fu

nctio

nal g

roup

s To

pic

20.1

—or

gani

c re

actio

ns

Topi

c 20

.3—

ster

eois

omer

ism

O

ptio

n C

.4—

biof

uels

B

iolo

gy to

pic

2.3—

carb

ohyd

rate

s

Aim

s:

• A

im 6

: Exp

erim

ents

cou

ld in

clud

e us

ing

Ben

edic

t’s o

r Feh

ling’

s so

lutio

n te

sts

to

dist

ingu

ish

betw

een

redu

cing

sug

ars

and

non-

redu

cing

sug

ars

or u

sing

iodi

ne

solu

tion

to te

st fo

r the

pre

senc

e of

sta

rch.

• A

im 8

: The

pro

duct

ion

of b

iofu

els

from

cro

ps ra

ises

man

y qu

estio

ns a

bout

re

late

d is

sues

suc

h as

def

ores

tatio

n, s

oil e

rosi

on a

nd s

usta

inab

ility

. The

“foo

d vs

fuel

” deb

ate

refe

rs to

the

cont

rove

rsie

s ar

isin

g fro

m d

evel

opm

ents

that

div

ert

agric

ultu

ral c

rops

into

bio

fuel

pro

duct

ion.

Core topics

Chemistry guide 129

Esse

ntia

l ide

a: V

itam

ins

are

orga

nic

mic

ronu

trien

ts w

ith d

iver

se fu

nctio

ns th

at m

ust b

e ob

tain

ed fr

om th

e di

et.

B.5

Vita

min

s

Nat

ure

of s

cien

ce:

Mak

ing

obse

rvat

ions

and

eva

luat

ing

clai

ms—

the

disc

over

y of

vita

min

s (v

ital a

min

es) i

s an

exa

mpl

e of

sci

entis

ts s

eeki

ng a

cau

se fo

r spe

cific

obs

erva

tions

. Thi

s re

sulte

d in

th

e ex

plan

atio

n of

def

icie

ncy

dise

ases

(eg

scur

vy a

nd b

erib

eri).

(1.8

)

Und

erst

andi

ngs:

• V

itam

ins

are

orga

nic

mic

ronu

trien

ts w

hich

(mos

tly) c

anno

t be

synt

hesi

zed

by

the

body

but

mus

t be

obta

ined

from

sui

tabl

e fo

od s

ourc

es.

• Th

e so

lubi

lity

(wat

er o

r fat

) of a

vita

min

can

be

pred

icte

d fro

m it

s st

ruct

ure.

• M

ost v

itam

ins

are

sens

itive

to h

eat.

• V

itam

in d

efic

ienc

ies

in th

e di

et c

ause

par

ticul

ar d

isea

ses

and

affe

ct m

illio

ns o

f pe

ople

wor

ldw

ide.

App

licat

ions

and

ski

lls:

• C

ompa

rison

of t

he s

truct

ures

of v

itam

ins

A, C

and

D.

• D

iscu

ssio

n of

the

caus

es a

nd e

ffect

s of

vita

min

def

icie

ncie

s in

diff

eren

t co

untri

es a

nd s

ugge

stio

n of

sol

utio

ns.

Gui

danc

e:

• Th

e st

ruct

ures

of v

itam

ins

A, C

and

D a

re p

rovi

ded

in th

e da

ta b

ookl

et s

ectio

n 35

.

• S

peci

fic fo

od s

ourc

es o

f vita

min

s or

nam

es o

f def

icie

ncy

dise

ases

do

not h

ave

to b

e le

arne

d.

Inte

rnat

iona

l-min

dedn

ess:

• Th

e fo

od s

uppl

emen

ts in

dust

ry, e

spec

ially

the

sale

of v

itam

in p

ills,

has

bec

ome

very

lucr

ativ

e in

man

y co

untri

es.

• V

itam

in D

def

icie

ncy

is in

crea

sing

, par

tly a

s a

resu

lt of

gre

ater

pro

tect

ion

of th

e sk

in fr

om s

unlig

ht.

Theo

ry o

f kno

wle

dge:

• W

hat a

re th

e et

hica

l con

side

ratio

ns in

add

ing

supp

lem

ents

to c

omm

only

co

nsum

ed fo

ods,

suc

h as

fluo

ride

to w

ater

or i

odin

e to

sal

t? P

ublic

bod

ies

can

prot

ect t

he in

divi

dual

but

als

o lim

it th

eir f

reed

om. H

ow d

o w

e kn

ow w

hat i

s be

st

for s

ocie

ty a

nd th

e in

divi

dual

?

• Li

nus

Pau

ling

is th

e on

ly m

an to

win

two

indi

vidu

al N

obel

Priz

es. H

is c

laim

that

vi

tam

in C

sup

plem

ents

cou

ld p

reve

nt d

isea

ses

such

as

the

com

mon

col

d le

d to

th

eir w

ides

prea

d us

e. W

hat i

s th

e ro

le o

f aut

horit

y in

com

mun

icat

ing

scie

ntifi

c kn

owle

dge

to th

e pu

blic

?

Util

izat

ion:

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

cs 4

.1, 4

.2 a

nd 4

.3—

stru

ctur

e an

d ph

ysic

al p

rope

rties

To

pic

10.1

—or

gani

c fu

nctio

nal g

roup

s To

pic

20.3

—co

nfig

urat

iona

l iso

mer

ism

B

iolo

gy o

ptio

n D

.2—

hum

an n

utrit

ion

and

heal

th

Aim

s:

• A

im 6

: Exp

erim

ents

cou

ld in

clud

e th

e D

CP

IP d

eter

min

atio

n of

vita

min

C le

vels

in

food

s.

Core topics

Chemistry guide130

Esse

ntia

l ide

a: O

ur in

crea

sing

kno

wle

dge

of b

ioch

emis

try h

as le

d to

sev

eral

env

ironm

enta

l pro

blem

s, w

hile

als

o he

lpin

g to

sol

ve o

ther

s.

B.6

Bio

chem

istr

y an

d th

e en

viro

nmen

t

Nat

ure

of s

cien

ce:

Ris

k as

sess

men

t, co

llabo

ratio

n, e

thic

al c

onsi

dera

tions

—it

is th

e re

spon

sibi

lity

of s

cien

tists

to c

onsi

der t

he w

ays

in w

hich

pro

duct

s of

thei

r res

earc

h an

d fin

ding

s ne

gativ

ely

impa

ct th

e en

viro

nmen

t, an

d to

find

way

s to

cou

nter

this

. For

exa

mpl

e, th

e us

e of

enz

ymes

in b

iolo

gica

l det

erge

nts

and

to b

reak

up

oil s

pills

, and

gre

en c

hem

istry

in g

ener

al.

(4.8

)

Und

erst

andi

ngs:

• Xe

nobi

otic

s re

fer t

o ch

emic

als

that

are

foun

d in

an

orga

nism

that

are

not

no

rmal

ly p

rese

nt th

ere.

• B

iode

grad

able

/com

post

able

pla

stic

s ca

n be

con

sum

ed o

r bro

ken

dow

n by

ba

cter

ia o

r oth

er li

ving

org

anis

ms.

• H

ost–

gues

t che

mis

try in

volv

es th

e cr

eatio

n of

syn

thet

ic h

ost m

olec

ules

that

m

imic

som

e of

the

actio

ns p

erfo

rmed

by

enzy

mes

in c

ells

, by

sele

ctiv

ely

bind

ing

to s

peci

fic g

uest

spe

cies

, suc

h as

toxi

c m

ater

ials

in th

e en

viro

nmen

t.

• E

nzym

es h

ave

been

dev

elop

ed to

hel

p in

the

brea

kdow

n of

oil

spill

s an

d ot

her

indu

stria

l was

tes.

• E

nzym

es in

bio

logi

cal d

eter

gent

s ca

n im

prov

e en

ergy

effi

cien

cy b

y en

ablin

g ef

fect

ive

clea

ning

at l

ower

tem

pera

ture

s.

• B

iom

agni

ficat

ion

is th

e in

crea

se in

con

cent

ratio

n of

a s

ubst

ance

in a

food

ch

ain.

• G

reen

che

mis

try, a

lso

calle

d su

stai

nabl

e ch

emis

try, i

s an

app

roac

h to

che

mic

al

rese

arch

and

eng

inee

ring

that

see

ks to

min

imiz

e th

e pr

oduc

tion

and

rele

ase

to

the

envi

ronm

ent o

f haz

ardo

us s

ubst

ance

s.

App

licat

ions

and

ski

lls:

• D

iscu

ssio

n of

the

incr

easi

ng p

robl

em o

f xen

obio

tics

such

as

antib

iotic

s in

se

wag

e tre

atm

ent p

lant

s.

• D

escr

iptio

n of

the

role

of s

tarc

h in

bio

degr

adab

le p

last

ics.

Inte

rnat

iona

l-min

dedn

ess:

• Th

e te

rm g

reen

che

mis

try w

as fi

rst c

oine

d in

199

1, a

nd a

ccep

tanc

e of

its

philo

soph

y ha

s le

d to

dev

elop

men

ts in

edu

catio

n an

d le

gisl

atio

n in

man

y co

untri

es.

• U

se o

f the

pes

ticid

e D

DT

is b

anne

d in

mos

t cou

ntrie

s du

e to

its

toxi

c ef

fect

s an

d bi

omag

nific

atio

n. It

s us

e co

ntin

ues,

how

ever

, in

coun

tries

whe

re m

alar

ia

rem

ains

a m

ajor

pub

lic h

ealth

cha

lleng

e.

Util

izat

ion:

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 4.

4—in

term

olec

ular

forc

es

Topi

c 10

.1—

natu

ral a

nd s

ynth

etic

org

anic

com

poun

ds

Opt

ions

A.5

and

A.7

—en

viro

nmen

tal i

mpa

ct o

f pla

stic

s O

ptio

n D

.2—

antib

iotic

s

Aim

s:

• A

im 6

: Exp

erim

ents

cou

ld in

clud

e th

e co

mpa

rison

of t

he b

reak

dow

n of

bi

odeg

rada

ble

and

non-

biod

egra

dabl

e pl

astic

s in

the

envi

ronm

ent.

• A

im 6

: Ris

k as

sess

men

t, in

clud

ing

the

risks

to th

e en

viro

nmen

t, is

an

esse

ntia

l pa

rt of

all

expe

rimen

tal w

ork.

• A

im 8

: The

dev

elop

men

t of t

he s

cien

ce o

f gre

en c

hem

istry

has

rais

ed

awar

enes

s of

the

envi

ronm

enta

l and

eth

ical

impl

icat

ions

of u

sing

sci

ence

and

te

chno

logy

.

Core topics

Chemistry guide 131

B.6

Bio

chem

istr

y an

d th

e en

viro

nmen

t

• A

pplic

atio

n of

hos

t–gu

est c

hem

istry

to th

e re

mov

al o

f a s

peci

fic p

ollu

tant

in th

e en

viro

nmen

t.

• D

escr

iptio

n of

an

exam

ple

of b

iom

agni

ficat

ion,

incl

udin

g th

e ch

emic

al s

ourc

e of

th

e su

bsta

nce.

Exa

mpl

es c

ould

incl

ude

heav

y m

etal

s or

pes

ticid

es.

• D

iscu

ssio

n of

the

chal

leng

es a

nd c

riter

ia in

ass

essi

ng th

e “g

reen

ness

” of a

su

bsta

nce

used

in b

ioch

emic

al re

sear

ch, i

nclu

ding

the

atom

eco

nom

y.

Gui

danc

e:

• S

peci

fic n

ames

of “

gree

n ch

emic

als”

suc

h as

sol

vent

s ar

e no

t exp

ecte

d.

• Th

e em

phas

is in

exp

lana

tions

of h

ost–

gues

t che

mis

try s

houl

d be

on

non-

cova

lent

bon

ding

with

in th

e su

pram

olec

ule.

Additional higher level topics

Chemistry guide132

Esse

ntia

l ide

a: A

naly

ses

of p

rote

in a

ctiv

ity a

nd c

once

ntra

tion

are

key

area

s of

bio

chem

ical

rese

arch

.

B.7

Pro

tein

s an

d en

zym

es

Nat

ure

of s

cien

ce:

Theo

ries

can

be s

uper

sede

d—“lo

ck a

nd k

ey” h

ypot

hesi

s to

“ind

uced

fit”

mod

el fo

r enz

ymes

. (1.

9)

Col

labo

ratio

n an

d et

hica

l con

side

ratio

ns—

scie

ntis

ts c

olla

bora

te to

syn

thes

ize

new

enz

ymes

and

to c

ontro

l des

ired

reac

tions

(ie

was

te c

ontro

l). (4

.5)

Und

erst

andi

ngs:

• In

hibi

tors

pla

y an

impo

rtant

role

in re

gula

ting

the

activ

ities

of e

nzym

es.

• A

min

o ac

ids

and

prot

eins

can

act

as

buffe

rs in

sol

utio

n.

• P

rote

in a

ssay

s co

mm

only

use

UV

-vis

spe

ctro

scop

y an

d a

calib

ratio

n cu

rve

base

d on

kno

wn

stan

dard

s.

App

licat

ions

and

ski

lls:

• D

eter

min

atio

n of

the

max

imum

rate

of r

eact

ion

(Vm

ax) a

nd th

e va

lue

of th

e M

icha

elis

con

stan

t (K

m) f

or a

n en

zym

e by

gra

phic

al m

eans

, and

exp

lana

tion

of

its s

igni

fican

ce.

• C

ompa

rison

of c

ompe

titiv

e an

d no

n-co

mpe

titiv

e in

hibi

tion

of e

nzym

es w

ith

refe

renc

e to

pro

tein

stru

ctur

e, th

e ac

tive

site

and

allo

ster

ic s

ite.

• E

xpla

natio

n of

the

conc

ept o

f pro

duct

inhi

bitio

n in

met

abol

ic p

athw

ays.

• C

alcu

latio

n of

the

pH o

f buf

fer s

olut

ions

, suc

h as

thos

e us

ed in

pro

tein

ana

lysi

s an

d in

reac

tions

invo

lvin

g am

ino

acid

s in

sol

utio

n.

• D

eter

min

atio

n of

the

conc

entra

tion

of a

pro

tein

in s

olut

ion

from

a c

alib

ratio

n cu

rve

usin

g th

e B

eer–

Lam

bert

law

.

Inte

rnat

iona

l-min

dedn

ess:

• Te

chno

logi

es b

ased

on

enzy

me

activ

ity g

o ba

ck to

anc

ient

tim

es in

man

y pa

rts

of th

e w

orld

. Bre

win

g an

d ch

eese

-mak

ing

are

ofte

n as

soci

ated

with

par

ticul

ar

plac

e na

mes

.

Theo

ry o

f kno

wle

dge:

• Th

e te

rm “l

ock-

and-

key”

is a

n ef

fect

ive

met

apho

r but

the

“indu

ced

fit” m

odel

is a

be

tter m

odel

. How

are

met

apho

rs a

nd m

odel

s us

ed in

the

cons

truct

ion

of

know

ledg

e?

Util

izat

ion:

• E

nzym

es a

re w

idel

y us

ed in

indu

stria

l and

dom

estic

app

licat

ions

. Exa

mpl

es

incl

ude

biol

ogic

al d

eter

gent

s, te

xtile

s, fo

ods

and

beve

rage

s, a

nd b

iode

grad

able

pl

astic

s. A

dvan

ces

in p

rote

in e

ngin

eerin

g ha

ve le

d to

the

synt

hesi

s of

enz

ymes

th

at a

re e

ffect

ive

in a

wid

e ra

nge

of c

ondi

tions

.

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 6.

1—ch

emic

al k

inet

ics

Topi

cs 8

.1, 8

.3 a

nd 8

.4—

the

pH s

cale

and

con

juga

te a

cids

and

bas

es

Topi

cs 1

8.2

and

18.3

—ac

id–b

ase

calc

ulat

ions

and

pH

cur

ves

Addi

tiona

l hig

her l

evel

topi

cs

Opt

ion

B: B

ioch

emis

try

15/2

5 ho

urs


Chemistry guide 133

B.7

Pro

tein

s an

d en

zym

es

Gui

danc

e:

• Th

e ef

fect

s of

com

petit

ive

and

non-

com

petit

ive

inhi

bito

rs o

n K

m a

nd V

max

val

ues

shou

ld b

e co

vere

d.

• Th

e H

ende

rson

–Has

selb

alch

equ

atio

n is

giv

en in

the

data

boo

klet

in s

ectio

n 1.

• Fo

r UV

-vis

spe

ctro

scop

y, k

now

ledg

e of

par

ticul

ar re

agen

ts a

nd w

avel

engt

hs is

no

t req

uire

d.

Aim

s:

• A

im 6

: Exp

erim

ents

cou

ld in

clud

e m

easu

ring

enzy

me

activ

ity w

ith c

hang

ing

cond

ition

s of

tem

pera

ture

, pH

and

hea

vy m

etal

ion

conc

entra

tion.

• A

im 7

: Dat

a-lo

ggin

g ex

perim

ents

with

tem

pera

ture

or p

H p

robe

s to

inve

stig

ate

enzy

me

activ

ity u

nder

diff

eren

t con

ditio

ns; o

r com

pute

r mod

ellin

g of

enz

yme–

subs

trate

inte

ract

ions

.

• A

im 8

: Man

y en

zym

e te

chno

logi

es h

elp

miti

gate

dam

agin

g en

viro

nmen

tal

effe

cts

of c

hem

ical

s, s

uch

as fr

om le

athe

r, pa

per a

nd o

il in

dust

ries.


Chemistry guide134

Esse

ntia

l ide

a: D

NA

is th

e ge

netic

mat

eria

l tha

t exp

ress

es it

self

by c

ontro

lling

the

synt

hesi

s of

pro

tein

s by

the

cell.

B.8

Nuc

leic

aci

ds

Nat

ure

of s

cien

ce:

Sci

entif

ic m

etho

d—th

e di

scov

ery

of th

e st

ruct

ure

of D

NA

is a

goo

d ex

ampl

e of

diff

eren

t app

roac

hes

to s

olvi

ng th

e sa

me

prob

lem

. Sci

entis

ts u

sed

mod

els

and

diffr

actio

n ex

perim

ents

to d

evel

op th

e st

ruct

ure

of D

NA

. (1.

3)

Dev

elop

men

ts in

sci

entif

ic re

sear

ch fo

llow

impr

ovem

ents

in a

ppar

atus

—do

uble

hel

ix fr

om X

-ray

diff

ract

ion

prov

ides

exp

lana

tion

for k

now

n fu

nctio

ns o

f DN

A. (

3.7)

Und

erst

andi

ngs:

• N

ucle

otid

es a

re th

e co

nden

satio

n pr

oduc

ts o

f a p

ento

se s

ugar

, pho

spho

ric a

cid

and

a ni

troge

nous

bas

e—ad

enin

e (A

), gu

anin

e (G

), cy

tosi

ne (C

), th

ymin

e (T

) or

urac

il (U

).

• P

olyn

ucle

otid

es fo

rm b

y co

nden

satio

n re

actio

ns.

• D

NA

is a

dou

ble

helix

of t

wo

poly

nucl

eotid

e st

rand

s he

ld to

geth

er b

y hy

drog

en

bond

s.

• R

NA

is u

sual

ly a

sin

gle

poly

nucl

eotid

e ch

ain

that

con

tain

s ur

acil

in p

lace

of

thym

ine,

and

a s

ugar

ribo

se in

pla

ce o

f deo

xyrib

ose.

• Th

e se

quen

ce o

f bas

es in

DN

A d

eter

min

es th

e pr

imar

y st

ruct

ure

of p

rote

ins

synt

hesi

zed

by th

e ce

ll us

ing

a tri

plet

cod

e, k

now

n as

the

gene

tic c

ode,

whi

ch

is u

nive

rsal

.

• G

enet

ical

ly m

odifi

ed o

rgan

ism

s ha

ve g

enet

ic m

ater

ial t

hat h

as b

een

alte

red

by

gene

tic e

ngin

eerin

g te

chni

ques

, inv

olvi

ng tr

ansf

errin

g D

NA

bet

wee

n sp

ecie

s.

App

licat

ions

and

ski

lls:

• E

xpla

natio

n of

the

stab

ility

of D

NA

in te

rms

of th

e in

tera

ctio

ns b

etw

een

its

hydr

ophi

lic a

nd h

ydro

phob

ic c

ompo

nent

s.

• E

xpla

natio

n of

the

orig

in o

f the

neg

ativ

e ch

arge

on

DN

A a

nd it

s as

soci

atio

n w

ith b

asic

pro

tein

s (h

isto

nes)

in c

hrom

osom

es.

• D

educ

tion

of th

e nu

cleo

tide

sequ

ence

in a

com

plem

enta

ry s

trand

of D

NA

or a

m

olec

ule

of R

NA

from

a g

iven

pol

ynuc

leot

ide

sequ

ence

.

Inte

rnat

iona

l-min

dedn

ess:

• Th

e H

uman

Gen

ome

Pro

ject

was

an

inte

rnat

iona

l res

earc

h pr

ogra

mm

e w

hose

go

al w

as to

com

plet

e th

e m

appi

ng a

nd s

eque

ncin

g of

all

the

gene

s in

the

hum

an g

enom

e.

• Th

e po

licie

s on

the

labe

lling

of g

enet

ical

ly m

odifi

ed (G

M) f

oods

var

y gr

eatly

in

diffe

rent

cou

ntrie

s.

• M

ost o

f the

gen

etic

ally

mod

ified

org

anis

ms

are

prot

ecte

d by

inte

rnat

iona

l pa

tent

s. W

hat e

ffect

doe

s th

is h

ave

on th

e gl

obal

eco

nom

y an

d sc

ient

ific

com

mun

ity?

Theo

ry o

f kno

wle

dge:

• D

NA

sto

res

info

rmat

ion

but n

ot k

now

ledg

e.

• W

hat a

re th

e di

ffere

nces

bet

wee

n in

form

atio

n an

d kn

owle

dge?

• Th

e N

obel

Priz

e in

Phy

siol

ogy

or M

edic

ine

1962

was

aw

arde

d jo

intly

to C

rick,

W

atso

n an

d W

ilkin

s "fo

r the

ir di

scov

erie

s co

ncer

ning

the

mol

ecul

ar s

truct

ure

of

nucl

eic

acid

s an

d its

sig

nific

ance

for i

nfor

mat

ion

trans

fer i

n liv

ing

mat

eria

l".

Wha

t is

the

role

of c

olla

bora

tion

in a

dvan

cing

kno

wle

dge?

• Th

e ex

iste

nce

of D

NA

dat

abas

es o

pens

up

ques

tions

of i

ndiv

idua

l priv

acy

and

the

exte

nt to

whi

ch g

over

nmen

t has

the

right

of a

cces

s to

per

sona

l inf

orm

atio

n.

Who

has

the

right

to a

cces

s kn

owle

dge

of a

n in

divi

dual

’s D

NA

?


Chemistry guide 135

B.8

Nuc

leic

aci

ds

• E

xpla

natio

n of

how

the

com

plem

enta

ry p

airin

g be

twee

n ba

ses

enab

les

DN

A to

re

plic

ate

itsel

f exa

ctly

.

• D

iscu

ssio

n of

the

bene

fits

and

conc

erns

of u

sing

gen

etic

ally

mod

ified

food

s.

Gui

danc

e:

• S

truct

ures

of t

he n

itrog

enou

s ba

ses

and

ribos

e an

d de

oxyr

ibos

e su

gars

are

gi

ven

in th

e da

ta b

ookl

et in

sec

tion

34.

• K

now

ledg

e of

the

diffe

rent

form

s of

RN

A is

not

requ

ired.

• D

etai

ls o

f the

pro

cess

of D

NA

repl

icat

ion

are

not r

equi

red.

• Li

mit

expr

essi

on o

f DN

A to

the

conc

ept o

f a fo

ur-u

nit b

ase

code

det

erm

inin

g a

twen

ty-u

nit a

min

o ac

id s

eque

nce.

Det

ails

of t

rans

crip

tion

and

trans

latio

n ar

e no

t req

uire

d.

Util

izat

ion:

• K

now

ledg

e of

DN

A s

eque

ncin

g ha

s tra

nsfo

rmed

sev

eral

asp

ects

of l

egal

en

quiry

, inc

ludi

ng fo

rens

ics

and

pate

rnity

cas

es. I

t is

also

wid

ely

used

in

stud

ies

of a

nces

try a

nd h

uman

mig

ratio

n.

• D

NA

seq

uenc

ing

is a

n im

porta

nt a

spec

t of t

he s

tudy

of b

ioch

emic

al e

volu

tion.

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 4.

4—hy

drog

en b

ondi

ng, i

nter

mol

ecul

ar in

tera

ctio

ns

Topi

c 8.

1—ac

id–b

ase

inte

ract

ions

B

iolo

gy to

pics

2.6

and

7.1

—D

NA

and

RN

A s

truct

ure

Aim

s:

• A

im 5

: The

sto

ry o

f the

riva

lry b

etw

een

the

diffe

rent

team

s in

volv

ed in

the

eluc

idat

ion

of D

NA

stru

ctur

e in

the

1950

s is

an

exam

ple

of a

failu

re o

f effe

ctiv

e co

llabo

ratio

n an

d co

mm

unic

atio

n du

ring

scie

ntifi

c ac

tiviti

es.

• A

im 6

: Exp

erim

ents

cou

ld in

clud

e D

NA

ext

ract

ion

from

cel

ls a

nd in

vest

igat

ion

of it

s ph

ysic

al p

rope

rties

, and

mod

el b

uild

ing

exer

cise

s of

DN

A s

truct

ure,

in

clud

ing

the

spec

ific

base

pai

rings

bet

wee

n a

purin

e an

d a

pyrim

idin

e.

• A

im 7

: Dat

abas

es e

xist

of g

enet

ic s

eque

nces

from

diff

eren

t org

anis

ms.

• A

im 8

: Man

y et

hica

l que

stio

ns a

re ra

ised

by

our k

now

ledg

e of

the

hum

an

geno

me,

incl

udin

g cl

onin

g, g

enet

ic e

ngin

eerin

g, g

ene

ther

apy,

and

so

on.


Chemistry guide136

Esse

ntia

l ide

a: B

iolo

gica

l pig

men

ts in

clud

e a

varie

ty o

f che

mic

al s

truct

ures

with

div

erse

func

tions

whi

ch a

bsor

b sp

ecifi

c w

avel

engt

hs o

f lig

ht.

B.9

Bio

logi

cal p

igm

ents

Nat

ure

of s

cien

ce:

Use

of d

ata—

quan

titat

ive

mea

sure

men

ts o

f abs

orba

nce

are

a re

liabl

e m

eans

of c

omm

unic

atin

g da

ta b

ased

on

colo

ur, w

hich

was

pre

viou

sly

subj

ectiv

e an

d di

fficu

lt to

re

plic

ate.

(3.1

)

Und

erst

andi

ngs:

• B

iolo

gica

l pig

men

ts a

re c

olou

red

com

poun

ds p

rodu

ced

by m

etab

olis

m.

• Th

e co

lour

of p

igm

ents

is d

ue to

hig

hly

conj

ugat

ed s

yste

ms

with

del

ocal

ized

el

ectro

ns, w

hich

hav

e in

tens

e ab

sorp

tion

band

s in

the

visi

ble

regi

on.

• P

orph

yrin

com

poun

ds, s

uch

as h

emog

lobi

n, m

yogl

obin

, chl

orop

hyll

and

man

y cy

toch

rom

es a

re c

hela

tes

of m

etal

s w

ith la

rge

nitro

gen-

cont

aini

ng m

acro

cycl

ic

ligan

ds.

• H

emog

lobi

n an

d m

yogl

obin

con

tain

hem

e gr

oups

with

the

porp

hyrin

gro

up

boun

d to

an

iron(

II) io

n.

• C

ytoc

hrom

es c

onta

in h

eme

grou

ps in

whi

ch th

e iro

n io

n in

terc

onve

rts b

etw

een

iron(

II) a

nd ir

on(II

I) du

ring

redo

x re

actio

ns.

• A

ntho

cyan

ins

are

arom

atic

, wat

er-s

olub

le p

igm

ents

wid

ely

dist

ribut

ed in

pla

nts.

Th

eir s

peci

fic c

olou

r dep

ends

on

met

al io

ns a

nd p

H.

• C

arot

enoi

ds a

re li

pid-

solu

ble

pigm

ents

, and

are

invo

lved

in h

arve

stin

g lig

ht in

ph

otos

ynth

esis

. The

y ar

e su

scep

tible

to o

xida

tion,

cat

alys

ed b

y lig

ht.

App

licat

ions

and

ski

lls:

• E

xpla

natio

n of

the

sigm

oida

l sha

pe o

f hem

oglo

bin’

s ox

ygen

dis

soci

atio

n cu

rve

in te

rms

of th

e co

oper

ativ

e bi

ndin

g of

hem

oglo

bin

to o

xyge

n.

• D

iscu

ssio

n of

the

fact

ors

that

influ

ence

oxy

gen

satu

ratio

n of

hem

oglo

bin,

in

clud

ing

tem

pera

ture

, pH

and

car

bon

diox

ide.

• D

escr

iptio

n of

the

grea

ter a

ffini

ty o

f oxy

gen

for f

oeta

l hem

oglo

bin.

Inte

rnat

iona

l-min

dedn

ess:

• A

rtific

ial c

olou

rs a

re c

omm

only

add

ed d

urin

g th

e co

mm

erci

al p

repa

ratio

n an

d pr

oces

sing

of f

ood.

The

list

of a

ppro

ved

food

col

ours

var

ies

grea

tly b

y co

untry

, w

hich

rais

es q

uest

ions

for i

nter

natio

nal t

rade

.

Theo

ry o

f kno

wle

dge:

• E

xper

imen

ts s

how

that

our

app

reci

atio

n of

food

is b

ased

on

an in

tera

ctio

n be

twee

n ou

r sen

ses.

How

do

the

diffe

rent

sen

ses

inte

ract

in g

ivin

g us

em

piric

al

know

ledg

e ab

out t

he w

orld

?

Util

izat

ion:

• D

iffer

ent t

ones

of s

kin,

eye

and

hai

r col

our a

re th

e re

sult

of d

iffer

ence

s in

the

conc

entra

tion

of th

e pi

gmen

t mel

anin

.

• P

eopl

e w

hose

anc

esto

rs h

ave

lived

at h

igh

altit

ude

for m

any

gene

ratio

ns h

ave

deve

lope

d he

mog

lobi

n w

ith a

hig

her a

ffini

ty fo

r oxy

gen.

• Th

e pu

rplis

h-re

d co

lour

of m

eat i

s la

rgel

y du

e to

the

pres

ence

of m

yogl

obin

. Th

e ch

ange

in c

olou

r to

brow

n on

coo

king

occ

urs

as th

e iro

n io

n be

com

es

oxid

ized

to F

e3+.

• A

ntho

cyan

ins

and

caro

teno

ids

prov

ide

visi

ble

sign

als

for p

lant

s to

attr

act

inse

cts

and

bird

s fo

r pol

linat

ion

and

seed

dis

pers

al. T

hey

also

pro

tect

pla

nts

from

dam

age

caus

ed b

y U

V li

ght.

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 8.

2—in

dica

tors

To

pic

13.2

—co

mpl

ex io

ns

Opt

ion

C.8

—el

ectro

nic

conj

ugat

ion

and

dye-

sens

itize

d so

lar c

ells


Chemistry guide 137

B.9

Bio

logi

cal p

igm

ents

• E

xpla

natio

n of

the

actio

n of

car

bon

mon

oxid

e as

a c

ompe

titiv

e in

hibi

tor o

f ox

ygen

bin

ding

.

• O

utlin

e of

the

fact

ors

that

affe

ct th

e st

abili

ties

of a

ntho

cyan

ins,

car

oten

oids

and

ch

loro

phyl

l in

rela

tion

to th

eir s

truct

ures

.

• E

xpla

natio

n of

the

abili

ty o

f ant

hocy

anin

s to

act

as

indi

cato

rs b

ased

on

thei

r se

nsiti

vity

to p

H.

• D

escr

iptio

n of

the

func

tion

of p

hoto

synt

hetic

pig

men

ts in

trap

ping

ligh

t ene

rgy

durin

g ph

otos

ynth

esis

.

• In

vest

igat

ion

of p

igm

ents

thro

ugh

pape

r and

thin

laye

r chr

omat

ogra

phy.

Gui

danc

e:

• Th

e st

ruct

ures

of c

hlor

ophy

ll, h

eme

B a

nd s

peci

fic e

xam

ples

of a

ntho

cyan

ins

and

caro

teno

ids

are

give

n in

the

data

boo

klet

in s

ectio

n 35

; det

ails

of o

ther

pi

gmen

t nam

es a

nd s

truct

ures

are

not

requ

ired.

• E

xpla

natio

n of

coo

pera

tive

bind

ing

in h

emog

lobi

n sh

ould

be

limite

d to

co

nfor

mat

iona

l cha

nges

occ

urrin

g in

one

pol

ypep

tide

whe

n it

beco

mes

ox

ygen

ated

.

• K

now

ledg

e of

spe

cific

col

our c

hang

es w

ith c

hang

ing

cond

ition

s is

not

requ

ired.

Aim

s:

• A

im 6

: Exp

erim

ents

cou

ld in

clud

e th

e ex

tract

ion

and

isol

atio

n of

pig

men

ts fr

om

plan

t sou

rces

usi

ng s

olve

nts

and

sepa

ratin

g fu

nnel

or t

he u

se o

f ant

hocy

anin

s as

pH

indi

cato

rs.

• A

im 7

: Use

of d

ata

logg

ers

for c

olle

ctin

g ab

sorp

tion

data

.


Chemistry guide138

Esse

ntia

l ide

a: M

ost b

ioch

emic

al p

roce

sses

are

ste

reos

peci

fic a

nd in

volv

e on

ly m

olec

ules

with

cer

tain

con

figur

atio

n of

chi

ral c

arbo

n at

oms.

B.1

0 St

ereo

chem

istr

y in

bio

mol

ecul

es

Nat

ure

of s

cien

ce:

Theo

ries

used

to e

xpla

in n

atur

al p

heno

men

a/ev

alua

te c

laim

s—bi

oche

mis

try in

volv

es m

any

chira

l mol

ecul

es w

ith b

iolo

gica

l act

ivity

spe

cific

to o

ne e

nant

iom

er. C

hem

ical

re

actio

ns in

a c

hira

l env

ironm

ent a

ct a

s a

guid

ing

dist

inct

ion

betw

een

livin

g an

d no

n-liv

ing

mat

ter.

(2.2

)

Und

erst

andi

ngs:

• W

ith o

ne e

xcep

tion,

am

ino

acid

s ar

e ch

iral,

and

only

the

L-co

nfig

urat

ion

is

foun

d in

pro

tein

s.

• N

atur

ally

occ

urrin

g un

satu

rate

d fa

t is

mos

tly in

the

cis

form

, but

food

pr

oces

sing

can

con

vert

it in

to th

e tra

ns fo

rm.

• D

and

L s

tere

oiso

mer

s of

sug

ars

refe

r to

the

conf

igur

atio

n of

the

chira

l car

bon

atom

furth

est f

rom

the

alde

hyde

or k

eton

e gr

oup,

and

D fo

rms

occu

r mos

t fre

quen

tly in

nat

ure.

• R

ing

form

s of

sug

ars

have

isom

ers,

kno

wn

as α

and

β, d

epen

ding

on

whe

ther

th

e po

sitio

n of

the

hydr

oxyl

gro

up a

t car

bon

1 (g

luco

se) o

r car

bon

2 (fr

ucto

se)

lies

belo

w th

e pl

ane

of th

e rin

g (α

) or a

bove

the

plan

e of

the

ring

(β).

• V

isio

n ch

emis

try in

volv

es th

e lig

ht a

ctiv

ated

inte

rcon

vers

ion

of c

is- a

nd tr

ans-

is

omer

s of

retin

al.

App

licat

ions

and

ski

lls:

• D

escr

iptio

n of

the

hydr

ogen

atio

n an

d pa

rtial

hyd

roge

natio

n of

uns

atur

ated

fats

, in

clud

ing

the

prod

uctio

n of

tran

s-fa

ts, a

nd a

dis

cuss

ion

of th

e ad

vant

ages

and

di

sadv

anta

ges

of th

ese

proc

esse

s.

• E

xpla

natio

n of

the

stru

ctur

e an

d pr

oper

ties

of c

ellu

lose

, and

com

paris

on w

ith

star

ch.

• D

iscu

ssio

n of

the

impo

rtanc

e of

cel

lulo

se a

s a

stru

ctur

al m

ater

ial a

nd in

the

diet

.

• O

utlin

e of

the

role

of v

itam

in A

in v

isio

n, in

clud

ing

the

role

s of

ops

in, r

hodo

psin

an

d ci

s- a

nd tr

ans-

retin

al.

Inte

rnat

iona

l-min

dedn

ess:

• D

iffer

ent c

ount

ries

have

ver

y di

ffere

nt s

tand

ards

of f

ood

labe

lling

with

resp

ect

to it

s ch

emic

al c

onte

nt, i

nclu

ding

the

type

of f

ats

pres

ent.

Util

izat

ion:

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 10

.1—

orga

nic

func

tiona

l gro

ups

Topi

c 20

.1—

orga

nic

reac

tions

To

pic

20.3

—st

ereo

isom

eris

m

Opt

ion

A.4

—in

term

olec

ular

/Lon

don

forc

es

Aim

s:

• A

im 8

: Eth

ical

que

stio

ns a

rise

thro

ugh

the

use

of s

atur

ated

and

tran

s-fa

ts,

parti

cula

rly in

the

fast

-food

indu

stry

.


Chemistry guide 139

B.1

0 St

ereo

chem

istr

y in

bio

mol

ecul

es

Gui

danc

e:

• N

ames

of t

he e

nzym

es in

volv

ed in

the

visu

al c

ycle

are

not

requ

ired.

• R

elat

ive

mel

ting

poin

ts o

f sat

urat

ed a

nd c

is-/t

rans

-uns

atur

ated

fats

sho

uld

be

cove

red.

Core topics

Chemistry guide140

Esse

ntia

l ide

a: S

ocie

ties

are

com

plet

ely

depe

nden

t on

ener

gy re

sour

ces.

The

qua

ntity

of e

nerg

y is

con

serv

ed in

any

con

vers

ion

but t

he q

ualit

y is

deg

rade

d.

C.1

Ene

rgy

sour

ces

Nat

ure

of s

cien

ce:

Use

theo

ries

to e

xpla

in n

atur

al p

heno

men

a—en

ergy

cha

nges

in th

e w

orld

aro

und

us re

sult

from

pot

entia

l and

kin

etic

ene

rgy

chan

ges

at th

e m

olec

ular

leve

l.

Ene

rgy

has

both

qua

ntity

and

qua

lity.

(2.2

)

Und

erst

andi

ngs:

• A

use

ful e

nerg

y so

urce

rele

ases

ene

rgy

at a

reas

onab

le ra

te a

nd p

rodu

ces

min

imal

pol

lutio

n.

• Th

e qu

ality

of e

nerg

y is

deg

rade

d as

hea

t is

trans

ferre

d to

the

surro

undi

ngs.

E

nerg

y an

d m

ater

ials

go

from

a c

once

ntra

ted

into

a d

ispe

rsed

form

. The

qu

antit

y of

the

ener

gy a

vaila

ble

for d

oing

wor

k de

crea

ses.

• R

enew

able

ene

rgy

sour

ces

are

natu

rally

repl

enis

hed.

Non

-rene

wab

le e

nerg

y so

urce

s ar

e fin

ite.

• E

nerg

y den

sity

= en

ergy

rele

ased

from

fuel

volu

me

of fu

el co

nsum

ed.

• Sp

ecifi

c ene

rgy=

ener

gy re

leas

ed fr

om fu

elm

ass o

f fue

l con

sum

ed.

• T

he ef

fecie

ncy o

f an e

nerg

y tra

nsfe

r= us

eful

out

put e

nerg

yto

tal i

nput

ener

gy x

100%

.

App

licat

ions

and

ski

lls:

• D

iscu

ssio

n of

the

use

of d

iffer

ent s

ourc

es o

f ren

ewab

le a

nd n

on-re

new

able

en

ergy

.

• D

eter

min

atio

n of

the

ener

gy d

ensi

ty a

nd s

peci

fic e

nerg

y of

a fu

el fr

om th

e en

thal

pies

of c

ombu

stio

n, d

ensi

ties

and

the

mol

ar m

ass

of fu

el.

• D

iscu

ssio

n of

how

the

choi

ce o

f fue

l is

influ

ence

d by

its

ener

gy d

ensi

ty o

r sp

ecifi

c en

ergy

.

Inte

rnat

iona

l-min

dedn

ess:

• Th

e In

tern

atio

nal E

nerg

y A

genc

y is

an

auto

nom

ous

orga

niza

tion

base

d in

Par

is

whi

ch w

orks

to e

nsur

e re

liabl

e, a

fford

able

and

cle

an e

nerg

y fo

r its

28

mem

ber

coun

tries

and

bey

ond.

• Th

e In

tern

atio

nal R

enew

able

Ene

rgy

Age

ncy

(IRE

NA

), ba

sed

in A

bu D

habi

, U

AE

, was

foun

ded

in 2

009

to p

rom

ote

incr

ease

d ad

optio

n an

d su

stai

nabl

e us

e of

rene

wab

le e

nerg

y so

urce

s (b

ioen

ergy

, geo

ther

mal

ene

rgy,

hyd

ropo

wer

, oc

ean,

sol

ar a

nd w

ind

ener

gy).

Theo

ry o

f kno

wle

dge:

• “I

have

no

doub

t tha

t we

will

be

succ

essf

ul in

har

ness

ing

the

sun’

s en

ergy

. If

sunb

eam

s w

ere

wea

pons

of w

ar w

e w

ould

hav

e ha

d so

lar e

nerg

y ce

ntur

ies

ago.

” (Lo

rd G

eorg

e P

orte

r). In

wha

t way

s m

ight

soc

ial,

polit

ical

, cul

tura

l and

re

ligio

us fa

ctor

s af

fect

the

type

s of

rese

arch

that

are

fina

nced

and

und

erta

ken,

or

reje

cted

?

• Th

ere

are

man

y et

hica

l iss

ues

rais

ed b

y en

ergy

gen

erat

ion

and

its c

onse

quen

t co

ntrib

utio

ns to

pol

lutio

n an

d cl

imat

e ch

ange

.Wha

t is

the

influ

ence

of p

oliti

cal

pres

sure

on

diffe

rent

are

as o

f kno

wle

dge?

Util

izat

ion:

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 5.

1—en

thal

pies

of c

ombu

stio

n

Topi

c 10

.2—

the

com

bust

ion

of h

ydro

carb

ons

E

nviro

nmen

tal s

yste

ms

and

soci

etie

s to

pics

—3.

2, 3

.3, 3

.5 a

nd 3

.6

Phy

sics

topi

c 8.

1—en

ergy

den

sity

Core

topi

cs

Opt

ion

C: E

nerg

y 15

/25

hour

s

Core topics

Chemistry guide 141

C.1

Ene

rgy

sour

ces

• D

eter

min

atio

n of

the

effic

ienc

y of

an

ener

gy tr

ansf

er p

roce

ss fr

om a

ppro

pria

te

data

.

• D

iscu

ssio

n of

the

adva

ntag

es a

nd d

isad

vant

ages

of t

he d

iffer

ent e

nerg

y so

urce

s in

C.2

thro

ugh

to C

.8.

Aim

s:

• A

im 1

: Dis

cuss

ions

of t

he p

ossi

ble

ener

gy s

ourc

es p

rovi

de o

ppor

tuni

ties

for

scie

ntifi

c st

udy

and

crea

tivity

with

in a

glo

bal c

onte

xt.

• A

im 6

: The

ene

rgy

dens

ity o

f diff

eren

t fue

ls c

ould

be

inve

stig

ated

ex

perim

enta

lly.

• A

im 7

: Dat

abas

es o

f ene

rgy

stat

istic

s on

a g

loba

l and

nat

iona

l sca

le c

an b

e ex

plor

ed h

ere.

• A

im 8

: Ene

rgy

prod

uctio

n ha

s gl

obal

eco

nom

ic a

nd e

nviro

nmen

tal d

imen

sion

s.

The

choi

ces

mad

e in

this

are

a ha

ve m

oral

and

eth

ical

impl

icat

ions

.

Core topics

Chemistry guide142

Esse

ntia

l ide

a: T

he e

nerg

y of

foss

il fu

els

orig

inat

es fr

om s

olar

ene

rgy

whi

ch h

as b

een

stor

ed b

y ch

emic

al p

roce

sses

ove

r tim

e. T

hese

abu

ndan

t res

ourc

es a

re n

on-re

new

able

bu

t pro

vide

larg

e am

ount

s of

ene

rgy

due

to th

e na

ture

of c

hem

ical

bon

ds in

hyd

roca

rbon

s.

C.2

Fos

sil f

uels

Nat

ure

of s

cien

ce:

Sci

entif

ic c

omm

unity

and

col

labo

ratio

n—th

e us

e of

foss

il fu

els

has

had

a ke

y ro

le in

the

deve

lopm

ent o

f sci

ence

and

tech

nolo

gy. (

4.1)

Und

erst

andi

ngs:

• Fo

ssil

fuel

s w

ere

form

ed b

y th

e re

duct

ion

of b

iolo

gica

l com

poun

ds th

at c

onta

in

carb

on, h

ydro

gen,

nitr

ogen

, sul

fur a

nd o

xyge

n.

• P

etro

leum

is a

com

plex

mix

ture

of h

ydro

carb

ons

that

can

be

split

into

diff

eren

t co

mpo

nent

par

ts c

alle

d fra

ctio

ns b

y fra

ctio

nal d

istil

latio

n.

• C

rude

oil

need

s to

be

refin

ed b

efor

e us

e. T

he d

iffer

ent f

ract

ions

are

sep

arat

ed

by a

phy

sica

l pro

cess

in fr

actio

nal d

istil

latio

n.

• Th

e te

nden

cy o

f a fu

el to

aut

o-ig

nite

, whi

ch le

ads

to “k

nock

ing”

in a

car

eng

ine,

is

rela

ted

to m

olec

ular

stru

ctur

e an

d m

easu

red

by th

e oc

tane

num

ber.

• Th

e pe

rform

ance

of h

ydro

carb

ons

as fu

els

is im

prov

ed b

y th

e cr

acki

ng a

nd

cata

lytic

refo

rmin

g re

actio

ns.

• C

oal g

asifi

catio

n an

d liq

uefa

ctio

n ar

e ch

emic

al p

roce

sses

that

con

vert

coal

to

gase

ous

and

liqui

d hy

droc

arbo

ns.

• A

car

bon

foot

prin

t is

the

tota

l am

ount

of g

reen

hous

e ga

ses

prod

uced

dur

ing

hum

an a

ctiv

ities

. It i

s ge

nera

lly e

xpre

ssed

in e

quiv

alen

t ton

s of

car

bon

diox

ide.

App

licat

ions

and

ski

lls:

• D

iscu

ssio

n of

the

effe

ct o

f cha

in le

ngth

and

cha

in b

ranc

hing

on

the

octa

ne

num

ber.

• D

iscu

ssio

n of

the

refo

rmin

g an

d cr

acki

ng re

actio

ns o

f hyd

roca

rbon

s an

d ex

plan

atio

n ho

w th

ese

proc

esse

s im

prov

e th

e oc

tane

num

ber.

• D

educ

tion

of e

quat

ions

for c

rack

ing

and

refo

rmin

g re

actio

ns, c

oal g

asifi

catio

n an

d liq

uefa

ctio

n.

Inte

rnat

iona

l-min

dedn

ess:

• Th

e ch

oice

of f

ossi

l fue

l use

d by

diff

eren

t cou

ntrie

s de

pend

s on

ava

ilabi

lity,

and

ec

onom

ic, s

ocie

tal,

envi

ronm

enta

l and

tech

nolo

gica

l fac

tors

.

• D

iffer

ent f

uel r

atin

g sy

stem

s (R

ON

, MO

N o

r PO

N) a

re u

sed

in d

iffer

ent

coun

tries

.

• O

cean

dril

ling,

oil

pipe

lines

and

oil

spill

s ar

e is

sues

that

dem

and

inte

rnat

iona

l co

oper

atio

n an

d ag

reem

ent.

Util

izat

ion:

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

cs 5

.1 a

nd 5

.3—

enth

alpy

cha

nges

of c

ombu

stio

n

Topi

cs 1

0.1

and

20.3

—hy

droc

arbo

ns a

nd is

omer

ism

To

pic

10.2

and

opt

ion

C.5

—gl

obal

war

min

g

Opt

ion

C.8

—so

lar c

ells

B

iolo

gy to

pic

4.3—

carb

on c

yclin

g

Aim

s:

• A

im 6

: Pos

sibl

e ex

perim

ents

incl

ude

fract

iona

l dis

tilla

tion

and

cata

lytic

cra

ckin

g re

actio

ns.

• A

im 7

: Dat

abas

es o

f ene

rgy

stat

istic

s on

a g

loba

l and

nat

iona

l sca

le c

an b

e ex

plor

ed h

ere.

• A

im 7

: Man

y on

line

calc

ulat

ors

are

avai

labl

e to

cal

cula

te c

arbo

n fo

otpr

ints

.

• A

im 8

: Con

side

ratio

n of

the

adva

ntag

es a

nd d

isad

vant

ages

of f

ossi

l fue

ls

illus

trate

s th

e ec

onom

ic a

nd e

nviro

nmen

tal i

mpl

icat

ions

of u

sing

sci

ence

and

te

chno

logy

.

Core topics

Chemistry guide 143

C.2

Fos

sil f

uels

• D

iscu

ssio

n of

the

adva

ntag

es a

nd d

isad

vant

ages

of t

he d

iffer

ent f

ossi

l fue

ls.

• Id

entif

icat

ion

of th

e va

rious

frac

tions

of p

etro

leum

, the

ir re

lativ

e vo

latil

ity a

nd

thei

r use

s.

• C

alcu

latio

ns o

f the

car

bon

diox

ide

adde

d to

the

atm

osph

ere,

whe

n di

ffere

nt

fuel

s bu

rn a

nd d

eter

min

atio

n of

car

bon

foot

prin

ts fo

r diff

eren

t act

iviti

es.

Gui

danc

e:

• Th

e co

st o

f pro

duct

ion

and

avai

labi

lity

(rese

rves

) of f

ossi

l fue

ls a

nd th

eir i

mpa

ct

on th

e en

viro

nmen

t sho

uld

be c

onsi

dere

d.

Core topics

Chemistry guide144

Esse

ntia

l ide

a: T

he fu

sion

of h

ydro

gen

nucl

ei in

the

sun

is th

e so

urce

of m

uch

of th

e en

ergy

nee

ded

for l

ife o

n E

arth

. The

re a

re m

any

tech

nolo

gica

l cha

lleng

es in

repl

icat

ing

this

pro

cess

on

Ear

th b

ut it

wou

ld o

ffer a

rich

sou

rce

of e

nerg

y. F

issi

on in

volv

es th

e sp

littin

g of

a la

rge

unst

able

nuc

leus

into

sm

alle

r sta

ble

nucl

ei.

C.3

Nuc

lear

fusi

on a

nd fi

ssio

n

Nat

ure

of s

cien

ce:

Ass

essi

ng th

e et

hics

of s

cien

tific

rese

arch

—w

ides

prea

d us

e of

nuc

lear

fiss

ion

for e

nerg

y pr

oduc

tion

wou

ld le

ad to

a re

duct

ion

in g

reen

hous

e ga

s em

issi

ons.

Nuc

lear

fiss

ion

is th

e pr

oces

s ta

king

pla

ce in

the

atom

ic b

omb

and

nucl

ear f

usio

n th

at in

the

hydr

ogen

bom

b. (4

.5)

Und

erst

andi

ngs:

Nuc

lear

fusi

on

• Li

ght n

ucle

i can

und

ergo

fusi

on re

actio

ns a

s th

is in

crea

ses

the

bind

ing

ener

gy

per n

ucle

on.

• Fu

sion

reac

tions

are

a p

rom

isin

g en

ergy

sou

rce

as th

e fu

el is

inex

pens

ive

and

abun

dant

, and

no

radi

oact

ive

was

te is

pro

duce

d.

• A

bsor

ptio

n sp

ectra

are

use

d to

ana

lyse

the

com

posi

tion

of s

tars

.

Nuc

lear

fiss

ion

• H

eavy

nuc

lei c

an u

nder

go fi

ssio

n re

actio

ns a

s th

is in

crea

ses

the

bind

ing

ener

gy

per n

ucle

on.

• 23

5 U u

nder

goes

a fi

ssio

n ch

ain

reac

tion:

U

235

92+

n1 0

→

U23

692

→ X

+ Y

+ n

eutro

ns.

• Th

e cr

itica

l mas

s is

the

mas

s of

fuel

nee

ded

for t

he re

actio

n to

be

self-

sust

aini

ng.

• 23

9 Pu,

use

d as

a fu

el in

“bre

eder

reac

tors

”, is

pro

duce

d fro

m 23

8 U b

y ne

utro

n ca

ptur

e.

• R

adio

activ

e w

aste

may

con

tain

isot

opes

with

long

and

sho

rt ha

lf-liv

es.

• H

alf-l

ife is

the

time

it ta

kes

for h

alf t

he n

umbe

r of a

tom

s to

dec

ay.

Inte

rnat

iona

l-min

dedn

ess:

• Th

e us

e of

nuc

lear

ene

rgy

is m

onito

red

inte

rnat

iona

lly b

y th

e In

tern

atio

nal

Ato

mic

Ene

rgy

Age

ncy.

• H

igh-

ener

gy p

artic

le p

hysi

cs re

sear

ch in

volv

es in

tern

atio

nal c

olla

bora

tion.

Th

ere

are

acce

lera

tor f

acili

ties

at C

ER

N, D

ES

Y, S

LAC

, Fer

mi l

ab a

nd

Bro

okha

ven.

Res

ults

are

dis

sem

inat

ed a

nd s

hare

d by

sci

entis

ts in

man

y co

untri

es.

• Th

e IT

ER

pro

ject

is a

col

labo

ratio

n be

twee

n m

any

coun

tries

and

aim

s to

de

mon

stra

te th

at fu

sion

is a

n en

ergy

sou

rce

of th

e fu

ture

.

Theo

ry o

f kno

wle

dge:

• Th

e us

e of

nuc

lear

ene

rgy

carri

es ri

sks

as w

ell a

s be

nefit

s. W

ho s

houl

d ul

timat

ely

be re

spon

sibl

e fo

r ass

essi

ng th

ese?

How

do

we

know

wha

t is

best

fo

r soc

iety

and

the

indi

vidu

al?

Util

izat

ion:

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 2.

1—is

otop

es

Topi

c 2.

2—th

e em

issi

on s

pect

rum

of h

ydro

gen

P

hysi

cs to

pic

7.2—

nucl

ear f

usio

n

Aim

s:

• A

im 7

: Com

pute

r ani

mat

ions

and

sim

ulat

ions

of r

adio

activ

e de

cay,

and

nuc

lear

fu

sion

and

fiss

ion

reac

tions

.

Core topics

Chemistry guide 145

C.3

Nuc

lear

fusi

on a

nd fi

ssio

n

App

licat

ions

and

ski

lls:

Nuc

lear

fusi

on

• C

onst

ruct

ion

of n

ucle

ar e

quat

ions

for f

usio

n re

actio

ns.

• E

xpla

natio

n of

fusi

on re

actio

ns in

term

s of

bin

ding

ene

rgy

per n

ucle

on.

• E

xpla

natio

n of

the

atom

ic a

bsor

ptio

n sp

ectra

of h

ydro

gen

and

heliu

m, i

nclu

ding

th

e re

latio

nshi

ps b

etw

een

the

lines

and

ele

ctro

n tra

nsiti

ons.

Nuc

lear

fiss

ion

• D

educ

tion

of n

ucle

ar e

quat

ions

for f

issi

on re

actio

ns.

• E

xpla

natio

n of

fiss

ion

reac

tions

in te

rms

of b

indi

ng e

nerg

y pe

r nuc

leon

.

• D

iscu

ssio

n of

the

stor

age

and

disp

osal

of n

ucle

ar w

aste

.

• S

olut

ion

of ra

dioa

ctiv

e de

cay

prob

lem

s in

volv

ing

inte

gral

num

bers

of h

alf-l

ives

.

Gui

danc

e:

• S

tude

nts

are

not e

xpec

ted

to re

call

spec

ific

fissi

on re

actio

ns.

• Th

e w

orki

ngs

of a

nuc

lear

pow

er p

lant

are

not

requ

ired.

• S

afet

y an

d ris

k is

sues

incl

ude:

hea

lth, p

robl

ems

asso

ciat

ed w

ith n

ucle

ar w

aste

an

d co

re m

eltd

own,

and

the

poss

ibili

ty th

at n

ucle

ar fu

els

may

be

used

in

nucl

ear w

eapo

ns.

• Th

e eq

uatio

ns, 𝑁𝑁

= 𝑁𝑁

0𝑒𝑒−𝜆𝜆

𝜆𝜆 and

𝑡𝑡1 2

= ln

2 𝜆𝜆 a

re g

iven

in s

ectio

n 1

of th

e da

ta

book

let.

• A

im 8

: Con

side

ratio

n of

the

envi

ronm

enta

l im

pact

of n

ucle

ar e

nerg

y ill

ustra

ting

the

impl

icat

ions

of u

sing

sci

ence

and

tech

nolo

gy.

Core topics

Chemistry guide146

Esse

ntia

l ide

a: V

isib

le li

ght c

an b

e ab

sorb

ed b

y m

olec

ules

that

hav

e a

conj

ugat

ed s

truct

ure

with

an

exte

nded

sys

tem

of a

ltern

atin

g si

ngle

and

mul

tiple

bon

ds. S

olar

ene

rgy

can

be c

onve

rted

to c

hem

ical

ene

rgy

in p

hoto

synt

hesi

s.

C.4

Sol

ar e

nerg

y

Nat

ure

of s

cien

ce:

Pub

lic u

nder

stan

ding

—ha

rnes

sing

the

sun’

s en

ergy

is a

cur

rent

are

a of

rese

arch

and

cha

lleng

es s

till r

emai

n. H

owev

er, c

onsu

mer

s an

d en

ergy

com

pani

es a

re b

eing

en

cour

aged

to m

ake

use

of s

olar

ene

rgy

as a

n al

tern

ativ

e en

ergy

sou

rce.

(5.2

)

Und

erst

andi

ngs:

• Li

ght c

an b

e ab

sorb

ed b

y ch

loro

phyl

l and

oth

er p

igm

ents

with

a c

onju

gate

d el

ectro

nic

stru

ctur

e.

• Ph

otos

ynth

esis

con

verts

ligh

t ene

rgy

into

che

mic

al e

nerg

y:

6CO

2 + 6

H2O

C

6H12

O6 +

6O

2

• Fe

rmen

tatio

n of

glu

cose

pro

duce

s et

hano

l whi

ch c

an b

e us

ed a

s a

biof

uel:

C6H

12O

6 2

C2H

5OH

+ 2

CO

2

• E

nerg

y co

nten

t of v

eget

able

oils

is s

imila

r to

that

of d

iese

l fue

l but

they

are

not

us

ed in

inte

rnal

com

bust

ion

engi

nes

as th

ey a

re to

o vi

scou

s.

• Tr

anse

ster

ifica

tion

betw

een

an e

ster

and

an

alco

hol w

ith a

stro

ng a

cid

or b

ase

cata

lyst

pro

duce

s a

diffe

rent

est

er:

RC

OO

R1 +

R2 O

H

RC

OO

R2 +

R1 O

H

• In

the

trans

este

rific

atio

n pr

oces

s, in

volv

ing

a re

actio

n w

ith a

n al

coho

l in

the

pres

ence

of a

stro

ng a

cid

or b

ase,

the

trigl

ycer

ide

vege

tabl

e oi

ls a

re c

onve

rted

to a

mix

ture

mai

nly

com

pris

ing

of a

lkyl

est

ers

and

glyc

erol

, but

with

som

e fa

tty

acid

s.

• Tr

anse

ster

ifica

tion

with

eth

anol

or m

etha

nol p

rodu

ces

oils

with

low

er v

isco

sity

th

at c

an b

e us

ed in

die

sel e

ngin

es.

App

licat

ions

and

ski

lls:

• Id

entif

icat

ion

of fe

atur

es o

f the

mol

ecul

es th

at a

llow

them

to a

bsor

b vi

sibl

e lig

ht.

Theo

ry o

f kno

wle

dge:

• Th

e cl

aim

s of

“col

d fu

sion

” wer

e di

smis

sed

as th

e re

sults

are

not

repr

oduc

ible

. Is

it a

lway

s po

ssib

le to

obt

ain

repl

icab

le re

sults

in th

e na

tura

l sci

ence

s? A

re

repr

oduc

ible

resu

lts p

ossi

ble

in o

ther

are

as o

f kno

wle

dge?

Util

izat

ion:

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 5.

3—bo

nd e

ntha

lpie

s

Topi

c 20

.1—

mec

hani

sm o

f nuc

lear

sub

stitu

tion

reac

tions

B

iolo

gy to

pic

2.9—

phot

osyn

thes

is

Aim

s:

• A

im 2

: The

con

vers

ion

of s

olar

ene

rgy

is im

porta

nt in

a n

umbe

r of d

iffer

ent

tech

nolo

gies

.

• A

im 6

: Exp

erim

ents

cou

ld in

clud

e th

ose

invo

lvin

g ph

otos

ynth

esis

, fer

men

tatio

n an

d tra

nses

terif

icat

ion.

• A

im 8

: Tra

nses

terif

icat

ion

reac

tions

, with

was

te c

ooki

ng o

il, c

ould

redu

ce w

aste

an

d pr

oduc

e ex

celle

nt b

iofu

els.

Core topics

Chemistry guide 147

C.4

Sol

ar e

nerg

y

• E

xpla

natio

n of

the

redu

ced

visc

osity

of e

ster

s pr

oduc

ed w

ith m

etha

nol a

nd

etha

nol.

• E

valu

atio

n of

the

adva

ntag

es a

nd d

isad

vant

ages

of t

he u

se o

f bio

fuel

s.

• D

educ

tion

of e

quat

ions

for t

rans

este

rific

atio

n re

actio

ns.

Gui

danc

e:

• O

nly

a co

njug

ated

sys

tem

with

alte

rnat

ing

doub

le b

onds

nee

ds to

be

cove

red.

Core topics

Chemistry guide148

Esse

ntia

l ide

a: G

ases

in th

e at

mos

pher

e th

at a

re p

rodu

ced

by h

uman

act

iviti

es a

re c

hang

ing

the

clim

ate

as th

ey a

re u

pset

ting

the

bala

nce

betw

een

radi

atio

n en

terin

g an

d le

avin

g th

e at

mos

pher

e.

C.5

Env

ironm

enta

l im

pact

—gl

obal

war

min

g

Nat

ure

of s

cien

ce:

Tran

sdis

cipl

inar

y—th

e st

udy

of g

loba

l war

min

g en

com

pass

es a

bro

ad ra

nge

of c

once

pts

and

idea

s an

d is

tran

sdis

cipl

inar

y. (4

.1)

Col

labo

ratio

n an

d si

gnifi

canc

e of

sci

ence

exp

lana

tions

to th

e pu

blic

—re

ports

of t

he In

terg

over

nmen

tal P

anel

on

Clim

ate

Cha

nge

(IPC

C).

(5.2

)

Cor

rela

tion

and

caus

e an

d un

ders

tand

ing

of s

cien

ce—

CO

2 lev

els

and

Ear

th a

vera

ge te

mpe

ratu

re s

how

cle

ar c

orre

latio

n bu

t wid

e va

riatio

ns in

the

surfa

ce te

mpe

ratu

re o

f the

E

arth

hav

e oc

curre

d fre

quen

tly in

the

past

. (2.

8)

Und

erst

andi

ngs:

• G

reen

hous

e ga

ses

allo

w th

e pa

ssag

e of

inco

min

g so

lar s

hort

wav

elen

gth

radi

atio

n bu

t abs

orb

the

long

er w

avel

engt

h ra

diat

ion

from

the

Ear

th. S

ome

of

the

abso

rbed

radi

atio

n is

re-ra

diat

ed b

ack

to E

arth

.

• Th

ere

is a

het

erog

eneo

us e

quili

briu

m b

etw

een

conc

entra

tion

of a

tmos

pher

ic

carb

on d

ioxi

de a

nd a

queo

us c

arbo

n di

oxid

e in

the

ocea

ns.

• G

reen

hous

e ga

ses

abso

rb IR

radi

atio

n as

ther

e is

a c

hang

e in

dip

ole

mom

ent

as th

e bo

nds

in th

e m

olec

ule

stre

tch

and

bend

.

• P

artic

ulat

es s

uch

as s

mok

e an

d du

st c

ause

glo

bal d

imm

ing

as th

ey re

flect

su

nlig

ht, a

s do

clo

uds.

App

licat

ions

and

ski

lls:

• E

xpla

natio

n of

the

mol

ecul

ar m

echa

nism

s by

whi

ch g

reen

hous

e ga

ses

abso

rb

infra

red

radi

atio

n.

• D

iscu

ssio

n of

the

evid

ence

for t

he re

latio

nshi

p be

twee

n th

e in

crea

sed

conc

entra

tion

of g

ases

and

glo

bal w

arm

ing.

• D

iscu

ssio

n of

the

sour

ces,

rela

tive

abun

danc

e an

d ef

fect

s of

diff

eren

t gr

eenh

ouse

gas

es.

• D

iscu

ssio

n of

the

diffe

rent

app

roac

hes

to th

e co

ntro

l of c

arbo

n di

oxid

e em

issi

ons.

Inte

rnat

iona

l-min

dedn

ess:

• Th

is is

sue

invo

lves

the

inte

rnat

iona

l com

mun

ity w

orki

ng to

geth

er to

rese

arch

an

d re

duce

the

effe

cts

of g

loba

l war

min

g. S

uch

atte

mpt

s in

clud

e th

e In

terg

over

nmen

tal P

anel

on

Clim

ate

Cha

nge

(IPC

C) a

nd th

e K

yoto

Pro

toco

l w

hich

was

ext

ende

d in

Qat

ar.

Theo

ry o

f kno

wle

dge:

• S

ome

peop

le q

uest

ion

the

real

ity o

f clim

ate

chan

ge, a

nd q

uest

ion

the

mot

ives

of

sci

entis

ts w

ho h

ave

“exa

gger

ated

” the

pro

blem

. How

do

we

asse

ss th

e ev

iden

ce c

olle

cted

and

the

mod

els

used

to p

redi

ct th

e im

pact

of h

uman

ac

tiviti

es?

Util

izat

ion:

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

cs 7

.1 a

nd 1

7.1—

equi

libriu

m s

yste

ms

To

pic

8.2—

acid

–bas

e eq

uilib

ria

Topi

c 11

.3—

infra

red

spec

tra

Topi

c 13

.2—

trans

ition

met

al c

ompl

exes

B

iolo

gy to

pic

4.4—

clim

ate

chan

ge

Phy

sics

topi

c 8.

1—th

erm

al e

nerg

y tra

nsfe

r

Aim

s:

• A

im 6

: The

equ

ilibr

ium

bet

wee

n aq

ueou

s an

d ga

seou

s ca

rbon

dio

xide

cou

ld b

e ex

perim

enta

lly in

vest

igat

ed.

Core topics

Chemistry guide 149

C.5

Env

ironm

enta

l im

pact

—gl

obal

war

min

g

• D

iscu

ssio

n of

pH

cha

nges

in th

e oc

ean

due

to in

crea

sed

conc

entra

tion

of

carb

on d

ioxi

de in

the

atm

osph

ere.

Gui

danc

e:

• G

reen

hous

e ga

ses

to b

e co

nsid

ered

are

CH

4, H

2O a

nd C

O2.

• A

im 7

: Com

pute

r mod

ellin

g is

a p

ower

ful t

ool b

y w

hich

kno

wle

dge

can

be

gain

ed a

bout

the

gree

nhou

se e

ffect

.

• A

im 8

: Dis

cuss

ions

of c

limat

e ch

ange

and

gre

en c

hem

istry

rais

e aw

aren

ess

of

the

ethi

cal,

econ

omic

and

env

ironm

enta

l im

plic

atio

ns o

f usi

ng s

cien

ce a

nd

tech

nolo

gy.


Chemistry guide150

Opt

ion

C: E

nerg

y 15

/25

hour

s

Addi

tiona

l hig

her l

evel

topi

cs

Esse

ntia

l ide

a: C

hem

ical

ene

rgy

from

redo

x re

actio

ns c

an b

e us

ed a

s a

porta

ble

sour

ce o

f ele

ctric

al e

nerg

y.

C.6

Ele

ctro

chem

istr

y, re

char

geab

le b

atte

ries

and

fuel

cel

ls

Nat

ure

of s

cien

ce:

Env

ironm

enta

l pro

blem

s—re

dox

reac

tions

can

be

used

as

a so

urce

of e

lect

ricity

but

dis

posa

l of b

atte

ries

has

envi

ronm

enta

l con

sequ

ence

s. (4

.8)

Und

erst

andi

ngs:

• A

n el

ectro

chem

ical

cel

l has

inte

rnal

resi

stan

ce d

ue to

the

finite

tim

e it

take

s fo

r io

ns to

diff

use.

The

max

imum

cur

rent

of a

cel

l is

limite

d by

its

inte

rnal

re

sist

ance

.

• Th

e vo

ltage

of a

bat

tery

dep

ends

prim

arily

on

the

natu

re o

f the

mat

eria

ls u

sed

whi

le

the

tota

l wor

k th

at c

an b

e ob

tain

ed fr

om it

dep

ends

on

thei

r qua

ntity

.

• In

a p

rimar

y ce

ll th

e el

ectro

chem

ical

reac

tion

is n

ot re

vers

ible

. Rec

harg

eabl

e ce

lls in

volv

e re

dox

reac

tions

that

can

be

reve

rsed

usi

ng e

lect

ricity

.

• A

fuel

cel

l can

be

used

to c

onve

rt ch

emic

al e

nerg

y, c

onta

ined

in a

fuel

that

is

cons

umed

, dire

ctly

to e

lect

rical

ene

rgy.

• M

icro

bial

fuel

cel

ls (M

FCs)

are

a p

ossi

ble

sust

aina

ble

ener

gy s

ourc

e us

ing

diffe

rent

car

bohy

drat

es o

r sub

stra

tes

pres

ent i

n w

aste

wat

ers

as th

e fu

el.

• Th

e N

erns

t equ

atio

n, E

= E

0 - (RT nF

) ln

Q, ca

n be

use

d to

cal

cula

te th

e po

tent

ial o

f a

half-

cell i

n an

ele

ctro

chem

ical

cel

l, un

der n

on-s

tand

ard

cond

ition

s.

• Th

e el

ectro

des

in a

con

cent

ratio

n ce

ll ar

e th

e sa

me

but t

he c

once

ntra

tion

of th

e el

ectro

lyte

sol

utio

ns a

t the

cat

hode

and

ano

de a

re d

iffer

ent.

App

licat

ions

and

ski

lls:

• D

istin

ctio

n be

twee

n fu

el c

ells

and

prim

ary

cells

.

• D

educ

tion

of h

alf e

quat

ions

for t

he e

lect

rode

reac

tions

in a

fuel

cel

l.

Inte

rnat

iona

l-min

dedn

ess:

• A

re b

atte

ry re

cycl

ing

prog

ram

mes

equ

ival

ent i

n di

ffere

nt a

reas

of t

he g

lobe

?

Theo

ry o

f kno

wle

dge:

• D

oes

scie

ntifi

c la

ngua

ge a

nd v

ocab

ular

y ha

ve p

rimar

ily a

des

crip

tive

or a

n in

terp

reta

tive

func

tion?

Are

the

term

s “e

lect

ric c

urre

nt” a

nd “i

nter

nal r

esis

tanc

e”

accu

rate

des

crip

tions

of r

ealit

y or

met

apho

rs?

Util

izat

ion:

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 9.

1—re

dox

reac

tions

To

pic

19.1

—el

ectro

chem

ical

cel

ls

Bio

logy

topi

c 6.

5—m

uscl

e an

d ne

rve

cells

dis

cuss

ed in

bio

logy

are

con

cent

ratio

n ce

lls

Phy

sics

topi

c 5.

3—th

e re

latio

nshi

p be

twee

n el

ectri

cal p

ower

, vol

tage

, res

ista

nce

and

curre

nt

Aim

s:

• A

im 2

: The

con

vers

ion

of c

hem

ical

ene

rgy

to e

lect

ricity

is im

porta

nt in

a

num

ber o

f diff

eren

t tec

hnol

ogie

s.

• A

im 6

: The

fact

ors

that

affe

ct th

e vo

ltage

of a

cel

l and

the

lead

–aci

d ba

ttery

co

uld

be in

vest

igat

ed e

xper

imen

tally

.


Chemistry guide 151

C.6

Ele

ctro

chem

istr

y, re

char

geab

le b

atte

ries

and

fuel

cel

ls

• C

ompa

rison

bet

wee

n fu

el c

ells

and

rech

arge

able

bat

terie

s.

• D

iscu

ssio

n of

the

adva

ntag

es o

f diff

eren

t typ

es o

f cel

ls in

term

s of

siz

e, m

ass

and

volta

ge.

• S

olut

ion

of p

robl

ems

usin

g th

e N

erns

t equ

atio

n.

• C

alcu

latio

n of

the

ther

mod

ynam

ic e

ffici

ency

(ΔG

/ΔH

) of a

fuel

cel

l.

• E

xpla

natio

n of

the

wor

king

s of

rech

arge

able

and

fuel

cel

ls in

clud

ing

diag

ram

s an

d re

leva

nt h

alf-e

quat

ions

.

Gui

danc

e:

• A

bat

tery

sho

uld

be c

onsi

dere

d as

a p

orta

ble

elec

troch

emic

al s

ourc

e m

ade

up

of o

ne o

r mor

e vo

ltaic

(gal

vani

c) c

ells

con

nect

ed in

ser

ies.

• Th

e N

erns

t equ

atio

n is

giv

en in

the

data

boo

klet

in s

ectio

n 1.

• H

ydro

gen

and

met

hano

l sho

uld

be c

onsi

dere

d as

fuel

s fo

r fue

l cel

ls. T

he o

pera

tion

of th

e ce

lls u

nder

aci

d an

d al

kalin

e co

nditi

ons

shou

ld b

e co

nsid

ered

. Stu

dent

s sh

ould

be

fam

iliar w

ith p

roto

n-ex

chan

ge m

embr

ane

(PEM

) fue

l cel

ls.

• Th

e G

eoba

cter

spe

cies

of b

acte

ria, f

or e

xam

ple,

can

be

used

in s

ome

cells

to

oxid

ize

the

etha

noat

e io

ns (C

H3C

OO

- ) un

der a

naer

obic

con

ditio

ns.

• Th

e le

ad–a

cid

stor

age

batte

ry, t

he n

icke

l–ca

dmiu

m (N

iCad

) bat

tery

and

the

lithi

um–i

on b

atte

ry s

houl

d be

con

side

red.

• S

tude

nts

shou

ld b

e fa

mili

ar w

ith th

e an

ode

and

cath

ode

half-

equa

tions

and

us

es o

f the

diff

eren

t cel

ls.

• A

im 8

: Con

side

ratio

n of

the

adva

ntag

es a

nd d

isad

vant

ages

of t

he d

iffer

ent

ener

gy s

ourc

es s

how

s th

e ec

onom

ic a

nd e

nviro

nmen

tal i

mpl

icat

ions

of u

sing

sc

ienc

e an

d te

chno

logy

. The

env

ironm

enta

l asp

ects

of f

uel c

ells

, esp

ecia

lly

with

rega

rd to

met

hano

l, co

uld

be d

iscu

ssed

.

• A

im 8

: Dis

posa

l of p

rimar

y ba

tterie

s an

d th

e ch

emic

als

they

use

can

intro

duce

la

nd a

nd w

ater

pol

lutio

n pr

oble

ms.

App

reci

atio

n of

the

envi

ronm

enta

l im

pact

of

cadm

ium

and

lead

pol

lutio

n.

• A

im 8

: Bac

teria

l fue

l cel

ls u

se s

ubst

rate

s fo

und

in w

aste

wat

er a

s th

e fu

el a

nd

so c

an b

e us

ed to

cle

an u

p th

e en

viro

nmen

t.


Chemistry guide152

Esse

ntia

l ide

a: L

arge

qua

ntiti

es o

f ene

rgy

can

be o

btai

ned

from

sm

all q

uant

ities

of m

atte

r.

C.7

Nuc

lear

fusi

on a

nd n

ucle

ar fi

ssio

n

Nat

ure

of s

cien

ce:

Tren

ds a

nd d

iscr

epan

cies

—ou

r und

erst

andi

ng o

f nuc

lear

pro

cess

es c

ame

from

bot

h th

eore

tical

and

exp

erim

enta

l adv

ance

s. In

term

olec

ular

forc

es in

UF 6

are

ano

mal

ous

and

do n

ot fo

llow

the

norm

al tr

ends

. (3.

1)

Und

erst

andi

ngs:

Nuc

lear

fusi

on:

• Th

e m

ass

defe

ct (∆

m) i

s th

e di

ffere

nce

betw

een

the

mas

s of

the

nucl

eus

and

the

sum

of t

he m

asse

s of

its

indi

vidu

al n

ucle

ons.

• Th

e nu

clea

r bin

ding

ene

rgy

(ΔE

) is

the

ener

gy re

quire

d to

sep

arat

e a

nucl

eus

into

pro

tons

and

neu

trons

.

Nuc

lear

fiss

ion:

• Th

e en

ergy

pro

duce

d in

a fi

ssio

n re

actio

n ca

n be

cal

cula

ted

from

the

mas

s di

ffere

nce

betw

een

the

prod

ucts

and

reac

tant

s us

ing

the

Ein

stei

n m

ass–

ener

gy

equi

vale

nce

rela

tions

hip

𝐸𝐸=

𝑚𝑚𝑚𝑚2 .

• Th

e di

ffere

nt is

otop

es o

f ura

nium

in u

rani

um h

exaf

luor

ide

can

be s

epar

ated

, us

ing

diffu

sion

or c

entri

fuga

tion

caus

ing

fuel

enr

ichm

ent.

• Th

e ef

fusi

on ra

te o

f a g

as is

inve

rsel

y pr

opor

tiona

l to

the

squa

re ro

ot o

f the

m

olar

mas

s (G

raha

m’s

Law

).

• R

adio

activ

e de

cay

is k

inet

ical

ly a

firs

t ord

er p

roce

ss w

ith th

e ha

lf-lif

e re

late

d to

th

e de

cay

cons

tant

by

the

equa

tion

𝜆𝜆=

ln2 𝑡𝑡 1 2

.

• Th

e da

nger

s of

nuc

lear

ene

rgy

are

due

to th

e io

nizi

ng n

atur

e of

the

radi

atio

n it

prod

uces

whi

ch le

ads

to th

e pr

oduc

tion

of o

xyge

n fre

e ra

dica

ls s

uch

as

supe

roxi

de (O

2- ), a

nd h

ydro

xyl (

HO

· ). T

hese

free

radi

cals

can

initi

ate

chai

n re

actio

ns th

at c

an d

amag

e D

NA

and

enz

ymes

in li

ving

cel

ls.

Inte

rnat

iona

l-min

dedn

ess:

• Th

ere

are

only

a v

ery

smal

l num

ber o

f cou

ntrie

s th

at h

ave

deve

lope

d nu

clea

r w

eapo

ns a

nd th

e In

tern

atio

nal A

tom

ic E

nerg

y A

genc

y st

rives

to li

mit

the

spre

ad

of th

is te

chno

logy

. The

re a

re d

ispu

tes

abou

t whe

ther

som

e co

untri

es a

re

deve

lopi

ng n

ucle

ar e

nerg

y fo

r pea

cefu

l or n

on-p

eace

ful p

urpo

ses.

• N

ucle

ar in

cide

nts

have

a g

loba

l effe

ct; t

he a

ccid

ents

at T

hree

Mile

Isla

nd a

nd

Che

rnob

yl a

nd th

e pr

oble

ms

at F

ukus

him

a ca

used

by

a ts

unam

i cou

ld b

e di

scus

sed

to il

lust

rate

the

pote

ntia

l dan

gers

.

Theo

ry o

f kno

wle

dge:

• “T

here

is n

o lik

elih

ood

that

hum

ans

will

eve

r tap

the

pow

er o

f the

ato

m.”

(Rob

ert M

illik

an, N

obel

Lau

reat

e P

hysi

cs 1

923

quot

ed in

192

8). H

ow c

an th

e im

pact

of n

ew te

chno

logi

es b

e pr

edic

ted?

How

relia

ble

are

thes

e pr

edic

tions

? H

ow im

porta

nt a

re th

e op

inio

ns o

f exp

erts

in th

e se

arch

for k

now

ledg

e?

• Th

e re

leas

e of

ene

rgy

durin

g fis

sion

reac

tions

can

be

used

in ti

mes

of p

eace

to

gene

rate

ene

rgy,

but

als

o ca

n le

ad to

des

truct

ion

in ti

me

of w

ar. S

houl

d sc

ient

ists

be

held

mor

ally

resp

onsi

ble

for t

he a

pplic

atio

ns o

f the

ir di

scov

erie

s?

Is th

ere

any

area

of s

cien

tific

kno

wle

dge

the

purs

uit o

f whi

ch is

mor

ally

un

acce

ptab

le?

Util

izat

ion:

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

cs 4

.1 a

nd 4

.3—

stru

ctur

e an

d bo

ndin

g

Topi

c 16

.1—

first

ord

er re

actio

ns

Phy

sics

topi

c 7.

2—nu

clea

r fus

ion

G

eogr

aphy

—th

e di

ffere

nt p

olic

es a

nd a

ttitu

des

to n

ucle

ar e

nerg

y ar

e di

scus

sed

in

reso

urce

s se

ctio

ns in

the

guid

e


Chemistry guide 153

C.7

Nuc

lear

fusi

on a

nd n

ucle

ar fi

ssio

n

App

licat

ions

and

ski

lls:

Nuc

lear

fusi

on:

• C

alcu

latio

n of

the

mas

s de

fect

and

bin

ding

ene

rgy

of a

nuc

leus

.

• A

pplic

atio

n of

the

Ein

stei

n m

ass–

ener

gy e

quiv

alen

ce re

latio

nshi

p, 𝐸𝐸

=𝑚𝑚𝑚𝑚2

, to

dete

rmin

e th

e en

ergy

pro

duce

d in

a fu

sion

reac

tion.

Nuc

lear

fiss

ion:

• A

pplic

atio

n of

the

Ein

stei

n m

ass–

ener

gy e

quiv

alen

ce re

latio

nshi

p to

det

erm

ine

the

ener

gy p

rodu

ced

in a

fiss

ion

reac

tion.

• D

iscu

ssio

n of

the

diffe

rent

pro

perti

es o

f UO

2 and

UF 6

in te

rms

of b

ondi

ng a

nd

stru

ctur

e.

• S

olut

ion

of p

robl

ems

invo

lvin

g ra

dioa

ctiv

e ha

lf-lif

e.

• E

xpla

natio

n of

the

rela

tions

hip

betw

een

Gra

ham

’s la

w o

f effu

sion

and

the

kine

tic th

eory

.

• S

olut

ion

of p

robl

ems

on th

e re

lativ

e ra

te o

f effu

sion

usi

ng G

raha

m’s

law

.

Gui

danc

e:

• S

tude

nts

are

not e

xpec

ted

to re

call

spec

ific

fissi

on re

actio

ns.

• Th

e w

orki

ngs

of a

nuc

lear

pow

er p

lant

are

not

requ

ired.

• S

afet

y an

d ris

k is

sues

incl

ude:

hea

lth, p

robl

ems

asso

ciat

ed w

ith n

ucle

ar w

aste

, an

d th

e po

ssib

ility

that

nuc

lear

fuel

s m

ay b

e us

ed in

nuc

lear

wea

pons

.

• G

raha

m’s

law

of e

ffusi

on is

giv

en in

the

data

boo

klet

in s

ectio

n 1.

• D

ecay

rela

tions

hips

are

giv

en in

the

data

boo

klet

in s

ectio

n 1.

• A

bin

ding

ene

rgy

curv

e is

giv

en in

the

data

boo

klet

in s

ectio

n 36

.

Aim

s:

• A

im 7

: Com

pute

r ani

mat

ions

and

sim

ulat

ions

of r

adio

activ

e de

cay,

and

nuc

lear

fu

sion

and

fiss

ion

reac

tions

.

• A

im 8

: Con

side

ratio

n of

the

adva

ntag

es a

nd d

isad

vant

ages

of n

ucle

ar fu

sion

ill

ustra

tes

the

econ

omic

and

env

ironm

enta

l im

plic

atio

ns o

f usi

ng s

cien

ce a

nd

tech

nolo

gy. T

he u

se o

f fus

ion

reac

tions

in th

e hy

drog

en b

omb

can

also

be

disc

usse

d.


Chemistry guide154

Esse

ntia

l ide

a: W

hen

sola

r ene

rgy

is c

onve

rted

to e

lect

rical

ene

rgy

the

light

mus

t be

abso

rbed

and

cha

rges

mus

t be

sepa

rate

d. In

a p

hoto

volta

ic c

ell b

oth

of th

ese

proc

esse

s oc

cur i

n th

e si

licon

sem

icon

duct

or, w

here

as th

ese

proc

esse

s oc

cur i

n se

para

te lo

catio

ns in

a d

ye-s

ensi

tized

sol

ar c

ell (

DS

SC

).

C.8

Pho

tovo

ltaic

cel

ls a

nd d

ye-s

ensi

tized

sol

ar c

ells

(DSS

C)

Nat

ure

of s

cien

ce:

Tran

sdis

cipl

inar

y—a

dye-

sens

itize

d so

lar c

ell,

who

se o

pera

tion

mim

ics

phot

osyn

thes

is a

nd m

akes

use

of T

iO2 na

nopa

rticl

es, i

llust

rate

s th

e tra

nsdi

scip

linar

y na

ture

of

scie

nce

and

the

link

betw

een

chem

istry

and

bio

logy

. (4.

1)

Fund

ing—

the

leve

l of f

undi

ng a

nd th

e so

urce

of t

he fu

ndin

g is

cru

cial

in d

ecis

ions

rega

rdin

g th

e ty

pe o

f res

earc

h to

be

cond

ucte

d. T

he fi

rst p

hoto

volta

ic c

ells

wer

e pr

oduc

ed

by N

AS

A fo

r spa

ce p

robe

s an

d w

ere

only

late

r use

d on

Ear

th. (

4.7)

Und

erst

andi

ngs:

• M

olec

ules

with

long

er c

onju

gate

d sy

stem

s ab

sorb

ligh

t of l

onge

r wav

elen

gth.

• Th

e el

ectri

cal c

ondu

ctiv

ity o

f a s

emic

ondu

ctor

incr

ease

s w

ith a

n in

crea

se in

te

mpe

ratu

re w

here

as th

e co

nduc

tivity

of m

etal

s de

crea

ses.

• Th

e co

nduc

tivity

of s

ilico

n ca

n be

incr

ease

d by

dop

ing

to p

rodu

ce n

-type

and

p-

type

sem

icon

duct

ors.

• S

olar

ene

rgy

can

be c

onve

rted

to e

lect

ricity

in a

pho

tovo

ltaic

cel

l.

• D

SS

Cs

imita

te th

e w

ay in

whi

ch p

lant

s ha

rnes

s so

lar e

nerg

y. E

lect

rons

are

"in

ject

ed" f

rom

an

exci

ted

mol

ecul

e di

rect

ly in

to th

e Ti

O2 se

mic

ondu

ctor

.

• Th

e us

e of

nan

opar

ticle

s co

ated

with

ligh

t-abs

orbi

ng d

ye in

crea

ses

the

effe

ctiv

e su

rface

are

a an

d al

low

s m

ore

light

ove

r a w

ider

rang

e of

the

visi

ble

spec

trum

to

be a

bsor

bed.

App

licat

ions

and

ski

lls:

• R

elat

ion

betw

een

the

degr

ee o

f con

juga

tion

in th

e m

olec

ular

stru

ctur

e an

d th

e w

avel

engt

h of

the

light

abs

orbe

d.

• E

xpla

natio

n of

the

oper

atio

n of

the

phot

ovol

taic

and

dye

-sen

sitiz

ed s

olar

cel

l.

• E

xpla

natio

n of

how

nan

opar

ticle

s in

crea

se th

e ef

ficie

ncy

of D

SS

Cs.

Inte

rnat

iona

l-min

dedn

ess:

• Th

e ha

rnes

sing

of s

olar

ene

rgy

coul

d ch

ange

the

econ

omic

fortu

nes

of

coun

tries

with

goo

d su

pplie

s of

sun

light

and

unu

sed

land

.

Theo

ry o

f kno

wle

dge:

• A

con

juga

ted

syst

em h

as s

ome

sim

ilarit

ies

with

a v

iolin

stri

ng. H

ow u

sefu

l is

this

met

apho

r? W

hat a

re th

e un

derly

ing

reas

ons

for t

hese

sim

ilarit

ies?

Wha

t ro

le d

o m

odel

s an

d m

etap

hors

pla

y in

the

acqu

isiti

on o

f kno

wle

dge?

Util

izat

ion:

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 3.

2—pa

ttern

s in

ioni

zatio

n en

ergy

To

pic

9.1—

redo

x re

actio

ns

Bio

logy

topi

c 2.

9—ph

otos

ynth

esis

Aim

s:

• A

im 6

: Stu

dent

s co

uld

build

an

inex

pens

ive

dye-

sens

itize

d so

lar c

ell a

nd

inve

stig

ate

thei

r pho

tovo

ltaic

pro

perti

es.

• A

im 7

: The

pro

perti

es o

f DSS

Cs

can

be b

est i

nves

tigat

ed u

sing

dat

a lo

gger

s.


Chemistry guide 155

C.8

Pho

tovo

ltaic

cel

ls a

nd d

ye-s

ensi

tized

sol

ar c

ells

(DSS

C)

• D

iscu

ssio

n of

the

adva

ntag

es o

f the

DSS

C c

ompa

red

to th

e si

licon

-bas

ed

phot

ovol

taic

cel

l.

Gui

danc

e:

• Th

e re

lativ

e co

nduc

tivity

of m

etal

s an

d se

mic

ondu

ctor

s sh

ould

be

rela

ted

to

ioni

zatio

n en

ergi

es.

• O

nly

a si

mpl

e tre

atm

ent o

f the

ope

ratio

n of

the

cells

is n

eede

d. In

p-ty

pe

sem

icon

duct

ors,

ele

ctro

n ho

les

in th

e cr

ysta

l are

cre

ated

by

intro

duci

ng a

sm

all

perc

enta

ge o

f a g

roup

3 e

lem

ent.

In n

-type

sem

icon

duct

ors

incl

usio

n of

a

grou

p 5

elem

ent p

rovi

des

extra

ele

ctro

ns.

• In

a p

hoto

volta

ic c

ell t

he li

ght i

s ab

sorb

ed a

nd th

e ch

arge

s se

para

ted

in th

e si

licon

sem

icon

duct

or. T

he p

roce

sses

of a

bsor

ptio

n an

d ch

arge

sep

arat

ion

are

sepa

rate

d in

a d

ye-s

ensi

tized

sol

ar c

ell.

• S

peci

fic re

dox

and

elec

trode

reac

tions

in th

e ne

wer

Grä

tzel

DS

SC

sho

uld

be

cove

red.

An

exam

ple

is th

e re

duct

ion

of I 2

/I 3─ io

ns to

I─.

Core topics

Chemistry guide156

Core

topi

cs

Opt

ion

D: M

edic

inal

che

mis

try

15 /2

5 ho

urs

Esse

ntia

l ide

a: M

edic

ines

and

dru

gs h

ave

a va

riety

of d

iffer

ent e

ffect

s on

the

func

tioni

ng o

f the

bod

y.

D.1

Pha

rmac

eutic

al p

rodu

cts

and

drug

act

ion

Nat

ure

of s

cien

ce:

Ris

ks a

nd b

enef

its—

med

icin

es a

nd d

rugs

go

thro

ugh

a va

riety

of t

ests

to d

eter

min

e th

eir e

ffect

iven

ess

and

safe

ty b

efor

e th

ey a

re m

ade

com

mer

cial

ly a

vaila

ble.

P

harm

aceu

tical

pro

duct

s ar

e cl

assi

fied

for t

heir

use

and

abus

e po

tent

ial.

(4.8

)

Und

erst

andi

ngs:

• In

ani

mal

stu

dies

, the

ther

apeu

tic in

dex

is th

e le

thal

dos

e of

a d

rug

for 5

0% o

f th

e po

pula

tion

(LD

50) d

ivid

ed b

y th

e m

inim

um e

ffect

ive

dose

for 5

0% o

f the

po

pula

tion

(ED

50).

• In

hum

ans,

the

ther

apeu

tic in

dex

is th

e to

xic

dose

of a

dru

g fo

r 50%

of t

he

popu

latio

n (T

D50

) div

ided

by

the

min

imum

effe

ctiv

e do

se fo

r 50%

of t

he

popu

latio

n (E

D50

).

• Th

e th

erap

eutic

win

dow

is th

e ra

nge

of d

osag

es b

etw

een

the

min

imum

am

ount

s of

the

drug

that

pro

duce

the

desi

red

effe

ct a

nd a

med

ical

ly

unac

cept

able

adv

erse

effe

ct.

• D

osag

e, to

lera

nce,

add

ictio

n an

d si

de e

ffect

s ar

e co

nsid

erat

ions

of d

rug

adm

inis

tratio

n.

• B

ioav

aila

bilit

y is

the

fract

ion

of th

e ad

min

iste

red

dosa

ge th

at re

ache

s th

e ta

rget

pa

rt of

the

hum

an b

ody.

• Th

e m

ain

step

s in

the

deve

lopm

ent o

f syn

thet

ic d

rugs

incl

ude

iden

tifyi

ng th

e ne

ed a

nd s

truct

ure,

syn

thes

is, y

ield

and

ext

ract

ion.

• D

rug–

rece

ptor

inte

ract

ions

are

bas

ed o

n th

e st

ruct

ure

of th

e dr

ug a

nd th

e si

te

of a

ctiv

ity.

Inte

rnat

iona

l-min

dedn

ess:

• In

som

e co

untri

es c

erta

in d

rugs

are

onl

y av

aila

ble

with

pre

scrip

tion

whi

le in

ot

her c

ount

ries

thes

e sa

me

drug

s ar

e av

aila

ble

over

the

coun

ter.

Theo

ry o

f kno

wle

dge:

• Th

e sa

me

drug

can

be

iden

tifie

d by

diff

eren

t nam

es. A

re n

ames

sim

ply

labe

ls

or d

o th

ey in

fluen

ce o

ur o

ther

way

s of

kno

win

g?

• D

rugs

tria

ls u

se d

oubl

e bl

ind

test

s. W

hen

is it

eth

ical

ly a

ccep

tabl

e to

dec

eive

pe

ople

?

• A

ll dr

ugs

carry

risk

s as

wel

l as

bene

fits.

Who

sho

uld

ultim

atel

y be

resp

onsi

ble

for a

sses

sing

thes

e? P

ublic

bod

ies

can

prot

ect t

he in

divi

dual

but

als

o lim

it th

eir

freed

om. H

ow d

o w

e kn

ow w

hat i

s be

st fo

r soc

iety

and

the

indi

vidu

al?

Aim

s:

• A

im 9

: The

re h

ave

been

adv

ance

s in

the

deve

lopm

ent o

f pha

rmac

eutic

als,

but

th

ere

are

man

y lim

itatio

ns to

thei

r im

pact

and

reac

h.

• A

im 1

0: T

he d

evel

opm

ent o

f new

med

icin

es is

ofte

n do

ne in

col

labo

ratio

n w

ith

biol

ogis

ts a

nd p

hysi

cist

s.

Core topics

Chemistry guide 157

D.1

Pha

rmac

eutic

al p

rodu

cts

and

drug

act

ion

App

licat

ions

and

ski

lls:

• D

iscu

ssio

n of

exp

erim

enta

l fou

ndat

ions

for t

hera

peut

ic in

dex

and

ther

apeu

tic

win

dow

thro

ugh

both

ani

mal

and

hum

an s

tudi

es.

• D

iscu

ssio

n of

dru

g ad

min

istra

tion

met

hods

.

• C

ompa

rison

of h

ow fu

nctio

nal g

roup

s, p

olar

ity a

nd m

edic

inal

adm

inis

tratio

n ca

n af

fect

bio

avai

labi

lity.

Gui

danc

e:

• Fo

r eth

ical

and

eco

nom

ic re

ason

s, a

nim

al a

nd h

uman

test

s of

dru

gs (f

or

LD50

/ED

50 a

nd T

D50

/ED

50 re

spec

tivel

y) s

houl

d be

kep

t to

a m

inim

um.

Core topics

Chemistry guide158

Esse

ntia

l ide

a: N

atur

al p

rodu

cts

with

use

ful m

edic

inal

pro

perti

es c

an b

e ch

emic

ally

alte

red

to p

rodu

ce m

ore

pote

nt o

r saf

er m

edic

ines

.

D.2

Asp

irin

and

peni

cilli

n

Nat

ure

of s

cien

ce:

Ser

endi

pity

and

sci

entif

ic d

isco

very

—th

e di

scov

ery

of p

enic

illin

by

Sir

Alex

ande

r Fle

min

g. (1

.4)

Mak

ing

obse

rvat

ions

and

repl

icat

ion

of d

ata—

man

y dr

ugs

need

to b

e is

olat

ed, i

dent

ified

and

mod

ified

from

nat

ural

sou

rces

. For

exa

mpl

e, s

alic

ylic

aci

d fro

m b

ark

of w

illow

tre

e fo

r rel

ief o

f pai

n an

d fe

ver.

(1.8

)

Und

erst

andi

ngs:

Asp

irin:

• M

ild a

nalg

esic

s fu

nctio

n by

inte

rcep

ting

the

pain

stim

ulus

at t

he s

ourc

e, o

ften

by in

terfe

ring

with

the

prod

uctio

n of

sub

stan

ces

that

cau

se p

ain,

sw

ellin

g or

fe

ver.

• A

spiri

n is

pre

pare

d fro

m s

alic

ylic

aci

d.

• A

spiri

n ca

n be

use

d as

an

antic

oagu

lant

, in

prev

entio

n of

the

recu

rrenc

e of

he

art a

ttack

s an

d st

roke

s an

d as

a p

roph

ylac

tic.

Pen

icilli

n:

• P

enic

illins

are

ant

ibio

tics

prod

uced

by

fung

i.

• A

bet

a-la

ctam

ring

is a

par

t of t

he c

ore

stru

ctur

e of

pen

icilli

ns.

• S

ome

antib

iotic

s w

ork

by p

reve

ntin

g cr

oss-

linki

ng o

f the

bac

teria

l cel

l wal

ls.

• M

odify

ing

the

side

-cha

in re

sults

in p

enic

illins

that

are

mor

e re

sist

ant t

o th

e pe

nici

llina

se e

nzym

e.

Inte

rnat

iona

l-min

dedn

ess:

• A

spiri

n is

use

d in

man

y di

ffere

nt w

ays

acro

ss th

e gl

obe.

• Th

e fir

st a

ntib

acte

rial c

hang

ed th

e w

ay th

at d

isea

se w

as tr

eate

d ac

ross

the

glob

e.

Theo

ry o

f kno

wle

dge:

• D

iffer

ent p

aink

iller

s ac

t in

diffe

rent

way

s. H

ow d

o w

e pe

rcei

ve p

ain,

and

how

ar

e ou

r per

cept

ions

influ

ence

d by

the

othe

r way

s of

kno

win

g?

• “C

hanc

e fa

vour

s on

ly th

e pr

epar

ed m

ind.

” (Lo

uis

Pas

teur

). Fl

emin

g’s

disc

over

y of

pen

icill

in is

ofte

n de

scrib

ed a

s se

rend

ipito

us b

ut th

e si

gnifi

canc

e of

his

ob

serv

atio

ns w

ould

hav

e be

en m

isse

d by

non

-exp

erts

. Wha

t inf

luen

ce d

oes

an

open

-min

ded

attit

ude

have

on

our p

erce

ptio

ns?

Util

izat

ion:

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 1.

3—yi

eld

of re

actio

n To

pic

10.2

—fu

nctio

nal g

roup

s B

iolo

gy to

pic

6.3—

defe

nce

agai

nst i

nfec

tious

dis

ease

Core topics

Chemistry guide 159

D.2

Asp

irin

and

peni

cilli

n

App

licat

ions

and

ski

lls:

Asp

irin

• D

escr

iptio

n of

the

use

of s

alic

ylic

aci

d an

d its

der

ivat

ives

as

mild

ana

lges

ics.

• E

xpla

natio

n of

the

synt

hesi

s of

asp

irin

from

sal

icyl

ic a

cid,

incl

udin

g yi

eld,

pur

ity

by re

crys

talli

zatio

n an

d ch

arac

teriz

atio

n us

ing

IR a

nd m

eltin

g po

int.

• D

iscu

ssio

n of

the

syne

rgis

tic e

ffect

s of

asp

irin

with

alc

ohol

.

• D

iscu

ssio

n of

how

the

aspi

rin c

an b

e ch

emic

ally

mod

ified

into

a s

alt t

o in

crea

se

its a

queo

us s

olub

ility

and

how

this

faci

litat

es it

s bi

oava

ilabi

lity.

Pen

icilli

n

• D

iscu

ssio

n of

the

effe

cts

of c

hem

ical

ly m

odify

ing

the

side

-cha

in o

f pen

icill

ins.

• D

iscu

ssio

n of

the

impo

rtanc

e of

pat

ient

com

plia

nce

and

the

effe

cts

of th

e ov

er-

pres

crip

tion

of p

enic

illin

.

• E

xpla

natio

n of

the

impo

rtanc

e of

the

beta

-lact

am ri

ng o

n th

e ac

tion

of p

enic

illin

.

Gui

danc

e:

• S

tude

nts

shou

ld b

e aw

are

of th

e ab

ility

of a

cidi

c (c

arbo

xylic

) and

bas

ic (a

min

o)

grou

ps to

form

ioni

c sa

lts, f

or e

xam

ple

solu

ble

aspi

rin.

• S

truct

ures

of a

spiri

n an

d pe

nici

llin

are

avai

labl

e in

the

data

boo

klet

in s

ectio

n 37

.

Aim

s:

• A

im 6

: Exp

erim

ents

cou

ld in

clud

e th

e sy

nthe

sis

of a

spiri

n.

• A

im 8

: Dis

cuss

the

use/

over

use

of a

ntib

iotic

s fo

r ani

mal

s.

Core topics

Chemistry guide160

Esse

ntia

l ide

a: P

oten

t med

ical

dru

gs p

repa

red

by c

hem

ical

mod

ifica

tion

of n

atur

al p

rodu

cts

can

be a

ddic

tive

and

beco

me

subs

tanc

es o

f abu

se.

D.3

Opi

ates

Nat

ure

of s

cien

ce:

Dat

a an

d its

sub

sequ

ent r

elat

ions

hips

—op

ium

and

its

man

y de

rivat

ives

hav

e be

en u

sed

as a

pai

nkill

er in

a v

arie

ty o

f for

ms

for t

hous

ands

of y

ears

. One

of t

hese

der

ivat

ives

is

dia

mor

phin

e. (3

.1)

Und

erst

andi

ngs:

• Th

e ab

ility

of a

dru

g to

cro

ss th

e bl

ood–

brai

n ba

rrier

dep

ends

on

its c

hem

ical

st

ruct

ure

and

solu

bilit

y in

wat

er a

nd li

pids

.

• O

piat

es a

re n

atur

al n

arco

tic a

nalg

esic

s th

at a

re d

eriv

ed fr

om th

e op

ium

pop

py.

• M

orph

ine

and

code

ine

are

used

as

stro

ng a

nalg

esic

s. S

trong

ana

lges

ics

wor

k by

tem

pora

rily

bond

ing

to re

cept

or s

ites

in th

e br

ain,

pre

vent

ing

the

trans

mis

sion

of p

ain

impu

lses

with

out d

epre

ssin

g th

e ce

ntra

l ner

vous

sys

tem

.

• M

edic

al u

se a

nd a

ddic

tive

prop

ertie

s of

opi

ate

com

poun

ds a

re re

late

d to

the

pres

ence

of o

pioi

d re

cept

ors

in th

e br

ain.

App

licat

ions

and

ski

lls:

• E

xpla

natio

n of

the

synt

hesi

s of

cod

eine

and

dia

mor

phin

e fro

m m

orph

ine.

• D

escr

iptio

n an

d ex

plan

atio

n of

the

use

of s

trong

ana

lges

ics.

• C

ompa

rison

of t

he s

truct

ures

of m

orph

ine,

cod

eine

and

dia

mor

phin

e (h

eroi

n).

• D

iscu

ssio

n of

the

adva

ntag

es a

nd d

isad

vant

ages

of u

sing

mor

phin

e an

d its

de

rivat

ives

as

stro

ng a

nalg

esic

s.

• D

iscu

ssio

n of

sid

e ef

fect

s an

d ad

dict

ion

to o

piat

e co

mpo

unds

.

• E

xpla

natio

n of

the

incr

ease

d po

tenc

y of

dia

mor

phin

e co

mpa

red

to m

orph

ine

base

d on

thei

r che

mic

al s

truct

ure

and

solu

bilit

y.

Gui

danc

e:

• S

truct

ures

of m

orph

ine,

cod

eine

and

dia

mor

phin

e ca

n be

foun

d in

the

data

bo

okle

t in

sect

ion

37.

Inte

rnat

iona

l-min

dedn

ess:

• M

any

illeg

al d

rugs

are

cul

tivat

ed o

r pro

duce

d in

a s

mal

l num

ber o

f cou

ntrie

s an

d th

en s

old

and

dist

ribut

ed g

loba

lly. C

ultu

ral a

nd e

cono

mic

vie

wpo

ints

diff

er

on th

e pr

oduc

tion

and

sale

of o

piat

es a

roun

d th

e w

orld

.

Theo

ry o

f kno

wle

dge:

• C

ultu

res

ofte

n cl

ash

over

diff

eren

t per

spec

tives

and

idea

s. Is

ther

e an

y kn

owle

dge

whi

ch is

inde

pend

ent o

f cul

ture

?

Util

izat

ion:

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 10

.2—

func

tiona

l gro

ups

Aim

s:

• A

im 7

: Use

com

pute

r ani

mat

ions

for t

he in

vest

igat

ion

of 3

-D v

isua

lizat

ions

of

drug

s an

d re

cept

or s

ites.

Core topics

Chemistry guide 161

Esse

ntia

l ide

a: E

xces

s st

omac

h ac

id is

a c

omm

on p

robl

em th

at c

an b

e al

levi

ated

by

com

poun

ds th

at in

crea

se th

e st

omac

h pH

by

neut

raliz

ing

or re

duci

ng it

s se

cret

ion.

D.4

pH

regu

latio

n of

the

stom

ach

Nat

ure

of s

cien

ce:

Col

lect

ing

data

thro

ugh

sam

plin

g an

d tri

allin

g—on

e of

the

sym

ptom

s of

dys

peps

ia is

the

over

prod

uctio

n of

sto

mac

h ac

id. M

edic

al tr

eatm

ent o

f thi

s co

nditi

on o

ften

incl

udes

th

e pr

escr

iptio

n of

ant

acid

s to

inst

antly

neu

traliz

e th

e ac

id, o

r H2-

rece

ptor

ant

agon

ists

or p

roto

n pu

mp

inhi

bito

rs w

hich

pre

vent

the

prod

uctio

n of

sto

mac

h ac

id. (

2.8)

Und

erst

andi

ngs:

• N

on-s

peci

fic re

actio

ns, s

uch

as th

e us

e of

ant

acid

s, a

re th

ose

that

wor

k to

re

duce

the

exce

ss s

tom

ach

acid

.

• A

ctiv

e m

etab

olite

s ar

e th

e ac

tive

form

s of

a d

rug

afte

r it h

as b

een

proc

esse

d by

th

e bo

dy.

App

licat

ions

and

ski

lls:

• E

xpla

natio

n of

how

exc

ess

acid

ity in

the

stom

ach

can

be re

duce

d by

the

use

of

diffe

rent

bas

es.

• C

onst

ruct

ion

and

bala

ncin

g of

equ

atio

ns fo

r neu

traliz

atio

n re

actio

ns a

nd th

e st

oich

iom

etric

app

licat

ion

of th

ese

equa

tions

.

• S

olvi

ng b

uffe

r pro

blem

s us

ing

the

Hen

ders

on–H

asse

lbal

ch e

quat

ion.

• E

xpla

natio

n of

how

com

poun

ds s

uch

as ra

nitid

ine

(Zan

tac)

can

be

used

to

inhi

bit s

tom

ach

acid

pro

duct

ion.

• E

xpla

natio

n of

how

com

poun

ds li

ke o

mep

razo

le (P

rilos

ec) a

nd e

som

epra

zole

(N

exiu

m) c

an b

e us

ed to

sup

pres

s ac

id s

ecre

tion

in th

e st

omac

h.

Gui

danc

e:

• A

ntac

id c

ompo

unds

sho

uld

incl

ude

calc

ium

hyd

roxi

de, m

agne

sium

hyd

roxi

de,

alum

iniu

m h

ydro

xide

, sod

ium

car

bona

te a

nd s

odiu

m b

icar

bona

te.

• S

truct

ures

for r

aniti

dine

and

om

epra

zole

can

be

foun

d in

the

data

boo

klet

in

sect

ion

37.

Inte

rnat

iona

l-min

dedn

ess:

• D

iffer

ent c

ultu

res

(ie d

iet,

lifes

tyle

, etc

) and

gen

etic

s ca

n af

fect

the

need

for p

H

regu

latio

n of

the

stom

ach.

Theo

ry o

f kno

wle

dge:

• S

omet

imes

we

utili

ze d

iffer

ent a

ppro

ache

s to

sol

ve th

e sa

me

prob

lem

. How

do

we

deci

de b

etw

een

com

petin

g ev

iden

ce a

nd a

ppro

ache

s?

Util

izat

ion:

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 1.

3—ca

lcul

atio

ns in

volv

ing

solu

tions

To

pics

8.2

and

8.4

—ne

utra

lizat

ion

Topi

c 10

.2—

func

tiona

l gro

ups

Topi

c 20

.3—

enan

tiom

ers

Opt

ion

B.7

—am

ino

acid

buf

fers

B

iolo

gy o

ptio

n D

.1—

dige

stio

n

Aim

s:

• A

im 6

: Exp

erim

ents

cou

ld in

clud

e tit

ratio

ns to

test

the

effe

ctiv

enes

s of

var

ious

an

taci

ds.

Core topics

Chemistry guide162

Esse

ntia

l ide

a: A

ntiv

iral m

edic

atio

ns h

ave

rece

ntly

bee

n de

velo

ped

for s

ome

vira

l inf

ectio

ns w

hile

oth

ers

are

still

bei

ng re

sear

ched

.

D.5

Ant

ivira

l med

icat

ions

Nat

ure

of s

cien

ce:

Sci

entif

ic c

olla

bora

tion—

rece

nt re

sear

ch in

the

scie

ntifi

c co

mm

unity

has

impr

oved

our

und

erst

andi

ng o

f how

viru

ses

inva

de o

ur s

yste

ms.

(4.1

)

Und

erst

andi

ngs:

• V

iruse

s la

ck a

cel

l stru

ctur

e an

d so

are

mor

e di

fficu

lt to

targ

et w

ith d

rugs

than

ba

cter

ia.

• A

ntiv

iral d

rugs

may

wor

k by

alte

ring

the

cell’

s ge

netic

mat

eria

l so

that

the

viru

s ca

nnot

use

it to

mul

tiply

. Alte

rnat

ivel

y, th

ey m

ay p

reve

nt th

e vi

ruse

s fro

m

mul

tiply

ing

by b

lock

ing

enzy

me

activ

ity w

ithin

the

host

cel

l.

App

licat

ions

and

ski

lls:

• E

xpla

natio

n of

the

diffe

rent

way

s in

whi

ch a

ntiv

iral m

edic

atio

ns w

ork.

• D

escr

iptio

n of

how

viru

ses

diffe

r fro

m b

acte

ria.

• E

xpla

natio

n of

how

ose

ltam

ivir

(Tam

iflu)

and

zan

amiv

ir (R

elen

za) w

ork

as a

pr

even

tativ

e ag

ent a

gain

st fl

u vi

ruse

s.

• C

ompa

rison

of t

he s

truct

ures

of o

selta

miv

ir an

d za

nam

ivir.

• D

iscu

ssio

n of

the

diffi

culti

es a

ssoc

iate

d w

ith s

olvi

ng th

e AI

DS

pro

blem

.

Gui

danc

e:

• S

truct

ures

for o

selta

miv

ir an

d za

nam

ivir

can

be fo

und

in th

e da

ta b

ookl

et in

se

ctio

n 37

.

Inte

rnat

iona

l-min

dedn

ess:

• H

ow h

as th

e A

IDS

epi

dem

ic c

hang

ed s

ince

its

disc

over

y in

the

early

198

0s?

Wha

t is

need

ed to

sto

p th

e sp

read

of t

he d

isea

se?

Wha

t is

the

glob

al im

pact

of

this

dis

ease

?

Util

izat

ion:

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Opt

ions

B.2

and

B.7

—pr

otei

ns a

nd e

nzym

es

Bio

logy

topi

c 11

.1—

vacc

inat

ion

Aim

s:

• A

im 8

: The

con

trol a

nd tr

eatm

ent o

f HIV

is e

xace

rbat

ed b

y th

e hi

gh p

rice

of

anti-

retro

vira

l age

nts

and

soci

ocul

tura

l iss

ues.

Core topics

Chemistry guide 163

Esse

ntia

l ide

a: T

he s

ynth

esis

, iso

latio

n, a

nd a

dmin

istra

tion

of m

edic

atio

ns c

an h

ave

an e

ffect

on

the

envi

ronm

ent.

D.6

Env

ironm

enta

l im

pact

of s

ome

med

icat

ions

Nat

ure

of s

cien

ce:

Eth

ical

impl

icat

ions

and

risk

s an

d pr

oble

ms—

the

scie

ntifi

c co

mm

unity

mus

t con

side

r bot

h th

e si

de e

ffect

s of

med

icat

ions

on

the

patie

nt a

nd th

e si

de e

ffect

s of

the

deve

lopm

ent,

prod

uctio

n an

d us

e of

med

icat

ions

on

the

envi

ronm

ent (

ie d

ispo

sal o

f nuc

lear

was

te, s

olve

nts

and

antib

iotic

was

te).

( 4.8

)

Und

erst

andi

ngs:

• H

igh-

leve

l was

te (H

LW) i

s w

aste

that

giv

es o

ff la

rge

amou

nts

of io

nizi

ng

radi

atio

n fo

r a lo

ng ti

me.

• Lo

w-le

vel w

aste

(LLW

) is

was

te th

at g

ives

off

smal

l am

ount

s of

ioni

zing

ra

diat

ion

for a

sho

rt tim

e.

• An

tibio

tic re

sista

nce

occu

rs w

hen

micr

o-or

gani

sms

beco

me

resis

tant

to a

ntib

acte

rials.

App

licat

ions

and

ski

lls:

• D

escr

ibe

the

envi

ronm

enta

l im

pact

of m

edic

al n

ucle

ar w

aste

dis

posa

l.

• D

iscu

ssio

n of

env

ironm

enta

l iss

ues

rela

ted

to le

ft-ov

er s

olve

nts.

• E

xpla

natio

n of

the

dang

ers

of a

ntib

iotic

was

te, f

rom

impr

oper

dru

g di

spos

al a

nd

anim

al w

aste

, and

the

deve

lopm

ent o

f ant

ibio

tic re

sist

ance

.

• D

iscu

ssio

n of

the

basi

cs o

f gre

en c

hem

istry

(sus

tain

able

che

mis

try) p

roce

sses

.

• E

xpla

natio

n of

how

gre

en c

hem

istry

was

use

d to

dev

elop

the

prec

urso

r for

Ta

mifl

u (o

selta

miv

ir).

Gui

danc

e:

• Th

e st

ruct

ure

of o

selta

miv

ir is

pro

vide

d in

the

data

boo

klet

in s

ectio

n 37

.

Inte

rnat

iona

l-min

dedn

ess:

• C

onsi

der h

ow p

harm

aceu

tical

com

pani

es d

eter

min

e ho

w to

spe

nd re

sear

ch

fund

s to

dev

elop

new

med

icat

ions

.

• D

o ph

arm

aceu

tical

com

pani

es h

ave

a re

spon

sibi

lity

to d

o re

sear

ch o

n ra

re

dise

ases

that

will

not

pro

vide

them

with

sig

nific

ant f

inan

cial

pro

fit?

• P

rodu

ctio

n of

a d

rug

typi

cally

invo

lves

a n

umbe

r of d

iffer

ent o

rgan

ic re

actio

ns.

Wha

t are

the

ethi

cs g

over

ning

the

desi

gn (s

ynth

esis

) of d

rugs

? D

o st

anda

rds

and

prac

tices

var

y by

cou

ntry

and

regi

on?

Theo

ry o

f kno

wle

dge:

• H

ow d

o w

e ba

lanc

e et

hica

l con

cern

s th

at a

ppea

r to

be a

t odd

s w

ith e

ach

othe

r w

hen

tryin

g to

form

ulat

e a

solu

tion

to th

e pr

oble

m?

Aim

s:

• A

im 8

: How

do

we

safe

ly d

ispo

se o

f med

icin

al n

ucle

ar w

aste

?

• A

im 8

: The

Pac

ific

yew

tree

whi

ch is

the

sour

ce o

f the

che

mot

hera

py d

rug

Taxo

l is

faci

ng e

xtin

ctio

n.

• A

im 8

: Sol

vent

dis

posa

l is

a gr

owin

g en

viro

nmen

tal p

robl

em.


Chemistry guide164

Esse

ntia

l ide

a: C

hira

l aux

iliar

ies

allo

w th

e pr

oduc

tion

of in

divi

dual

ena

ntio

mer

s of

chi

ral m

olec

ules

.

D.7

Tax

ol—

a ch

iral a

uxili

ary

case

stu

dy

Nat

ure

of s

cien

ce:

Adv

ance

s in

tech

nolo

gy—

man

y of

thes

e na

tura

l sub

stan

ces

can

now

be

prod

uced

in la

bora

torie

s in

hig

h en

ough

qua

ntiti

es to

sat

isfy

the

dem

and.

(3.7

)

Ris

ks a

nd p

robl

ems—

the

dem

and

for c

erta

in d

rugs

has

exc

eede

d th

e su

pply

of n

atur

al s

ubst

ance

s ne

eded

to s

ynth

esiz

e th

ese

drug

s. (4

.8)

Und

erst

andi

ngs:

• Ta

xol i

s a

drug

that

is c

omm

only

use

d to

trea

t sev

eral

diff

eren

t for

ms

of c

ance

r.

• Ta

xol n

atur

ally

occ

urs

in y

ew tr

ees

but i

s no

w c

omm

only

syn

thet

ical

ly

prod

uced

.

• A

chi

ral a

uxili

ary

is a

n op

tical

ly a

ctiv

e su

bsta

nce

that

is te

mpo

raril

y in

corp

orat

ed in

to a

n or

gani

c sy

nthe

sis

so th

at it

can

be

carri

ed o

ut

asym

met

rical

ly w

ith th

e se

lect

ive

form

atio

n of

a s

ingl

e en

antio

mer

.

App

licat

ions

and

ski

lls:

• E

xpla

natio

n of

how

taxo

l (pa

clita

xel)

is o

btai

ned

and

used

as

a ch

emot

hera

peut

ic a

gent

.

• D

escr

iptio

n of

the

use

of c

hira

l aux

iliar

ies

to fo

rm th

e de

sire

d en

antio

mer

.

• E

xpla

natio

n of

the

use

of a

pol

arim

eter

to id

entif

y en

antio

mer

s.

Gui

danc

e:

• Th

e st

ruct

ure

of ta

xol i

s pr

ovid

ed in

the

data

boo

klet

in s

ectio

n 37

.

Inte

rnat

iona

l-min

dedn

ess:

• Th

ere

is a

n un

equa

l ava

ilabi

lity

and

dist

ribut

ion

of c

erta

in d

rugs

and

med

icin

es

arou

nd th

e gl

obe.

Util

izat

ion:

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 20

.2—

synt

hetic

rout

es

Topi

c 20

.3—

ster

eois

omer

ism

Aim

s:

• A

im 8

: Con

side

r the

eth

ical

impl

icat

ions

of u

sing

syn

thet

ic d

rugs

inst

ead

of

natu

ral s

ourc

es.

Addi

tiona

l hig

her l

evel

topi

cs

Opt

ion

D: M

edic

inal

che

mis

try

15 /2

5 ho

urs


Chemistry guide 165

Esse

ntia

l ide

a: N

ucle

ar ra

diat

ion,

whi

lst d

ange

rous

ow

ing

to it

s ab

ility

to d

amag

e ce

lls a

nd c

ause

mut

atio

ns, c

an a

lso

be u

sed

to b

oth

diag

nose

and

cur

e di

seas

es.

D.8

Nuc

lear

med

icin

e

Nat

ure

of s

cien

ce:

Ris

ks a

nd b

enef

its—

it is

impo

rtant

to tr

y an

d ba

lanc

e th

e ris

k of

exp

osur

e to

radi

atio

n w

ith th

e be

nefit

of t

he te

chni

que

bein

g co

nsid

ered

. (4.

8)

Und

erst

andi

ngs:

• A

lpha

, bet

a, g

amm

a, p

roto

n, n

eutro

n an

d po

sitro

n em

issi

ons

are

all u

sed

for

med

ical

trea

tmen

t.

• M

agne

tic re

sona

nce

imag

ing

(MR

I) is

an

appl

icat

ion

of N

MR

tech

nolo

gy.

• R

adio

ther

apy

can

be in

tern

al a

nd/o

r ext

erna

l.

• Ta

rget

ed A

lpha

The

rapy

(TA

T) a

nd B

oron

Neu

tron

Cap

ture

The

rapy

(BN

CT)

ar

e tw

o m

etho

ds w

hich

are

use

d in

can

cer t

reat

men

t.

App

licat

ions

and

ski

lls:

• D

iscu

ssio

n of

com

mon

sid

e ef

fect

s fro

m ra

diot

hera

py.

• E

xpla

natio

n of

why

tech

netiu

m-9

9m is

the

mos

t com

mon

radi

oiso

tope

use

d in

nu

clea

r med

icin

e ba

sed

on it

s ha

lf-lif

e, e

mis

sion

type

and

che

mis

try.

• E

xpla

natio

n of

why

lute

tium

-177

and

yttr

ium

-90

are

com

mon

isot

opes

use

d fo

r ra

diot

hera

py b

ased

on

the

type

of r

adia

tion

emitt

ed.

• B

alan

cing

nuc

lear

equ

atio

ns in

volv

ing

alph

a an

d be

ta p

artic

les.

• C

alcu

latio

n of

the

perc

enta

ge a

nd a

mou

nt o

f rad

ioac

tive

mat

eria

l dec

ayed

and

re

mai

ning

afte

r a c

erta

in p

erio

d of

tim

e us

ing

the

nucl

ear h

alf-l

ife e

quat

ion.

• E

xpla

natio

n of

TA

T an

d ho

w it

mig

ht b

e us

ed to

trea

t dis

ease

s th

at h

ave

spre

ad

thro

ugho

ut th

e bo

dy.

Gui

danc

e:

• C

omm

on s

ide

effe

cts

disc

usse

d sh

ould

inclu

de h

air l

oss,

nau

sea,

fatig

ue a

nd s

teril

ity.

Disc

ussio

n sh

ould

inclu

de th

e da

mag

e to

DN

A an

d gr

owin

g or

rege

nera

ting

tissu

e.

• Is

otop

es u

sed

in n

ucle

ar m

edici

ne in

cludi

ng; T

c-99

m, L

u-17

7, Y

-90,

I-13

1 an

d Pb

-212

.

Inte

rnat

iona

l-min

dedn

ess:

• Th

e us

e of

nuc

lear

tech

nolo

gy in

med

ical

trea

tmen

ts is

not

con

sist

ent a

cros

s th

e gl

obe.

Cul

ture

, cos

t, av

aila

bilit

y an

d be

liefs

are

som

e fa

ctor

s th

at c

an

influ

ence

its

use.

Theo

ry o

f kno

wle

dge:

• Th

ere

is o

ften

no re

fere

nce

to th

e te

rm “n

ucle

ar” i

n M

RI.

Are

nam

es s

impl

y la

bels

or d

o th

ey in

fluen

ce o

ur o

ther

way

s of

kno

win

g? H

ow d

oes

publ

ic

perc

eptio

n in

fluen

ce s

cien

tific

pro

gres

s an

d im

plem

enta

tion?

Util

izat

ion:

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

cs 1

1.3

and

21.1

—N

MR

O

ptio

ns C

.3 a

nd C

.7—

nucl

ear r

eact

ions

and

hal

f-life

P

hysi

cs o

ptio

n C

.4—

med

ical

imag

ing.


Chemistry guide166

Esse

ntia

l ide

a: A

var

iety

of a

naly

tical

tech

niqu

es is

use

d fo

r det

ectio

n, id

entif

icat

ion,

isol

atio

n an

d an

alys

is o

f med

icin

es a

nd d

rugs

.

D.9

Dru

g de

tect

ion

and

anal

ysis

Nat

ure

of s

cien

ce:

Adv

ance

s in

inst

rum

enta

tion—

adva

nces

in te

chno

logy

(IR

, MS

and

NM

R) h

ave

assi

sted

in d

rug

dete

ctio

n, is

olat

ion

and

purif

icat

ion.

(3.7

)

Und

erst

andi

ngs:

• O

rgan

ic s

truct

ures

can

be

anal

ysed

and

iden

tifie

d th

roug

h th

e us

e of

infra

red

spec

trosc

opy,

mas

s sp

ectro

scop

y an

d pr

oton

NM

R.

• Th

e pr

esen

ce o

f alc

ohol

in a

sam

ple

of b

reat

h ca

n be

det

ecte

d th

roug

h th

e us

e of

eith

er a

redo

x re

actio

n or

a fu

el c

ell t

ype

of b

reat

haly

ser.

App

licat

ions

and

ski

lls:

• In

terp

reta

tion

of a

var

iety

of a

naly

tical

spe

ctra

to d

eter

min

e an

org

anic

stru

ctur

e in

clud

ing

infra

red

spec

trosc

opy,

mas

s sp

ectro

scop

y an

d pr

oton

NM

R.

• D

escr

iptio

n of

the

proc

ess

of e

xtra

ctio

n an

d pu

rific

atio

n of

an

orga

nic

prod

uct.

Con

side

r the

use

of f

ract

iona

l dis

tilla

tion,

Rao

ult’s

law

, the

pro

perti

es o

n w

hich

ex

tract

ions

are

bas

ed a

nd e

xpla

inin

g th

e re

latio

nshi

p be

twee

n or

gani

c st

ruct

ure

and

solu

bilit

y.

• D

escr

iptio

n of

the

proc

ess

of s

tero

id d

etec

tion

in s

port

utili

zing

chr

omat

ogra

phy

and

mas

s sp

ectro

scop

y.

• E

xpla

natio

n of

how

alc

ohol

can

be

dete

cted

with

the

use

of a

bre

atha

lyse

r.

Gui

danc

e:

• S

tude

nts

shou

ld b

e ab

le to

iden

tify

com

mon

org

anic

func

tiona

l gro

ups

in a

gi

ven

com

poun

d by

reco

gniti

on o

f com

mon

dru

g st

ruct

ures

and

from

IR

(sec

tion

26 o

f the

dat

a bo

okle

t), 1 H

NM

R (s

ectio

n 27

of t

he d

ata

book

let)

and

mas

s sp

ectra

l fra

gmen

t (se

ctio

n 28

of t

he d

ata

book

let)

data

.

• A

com

mon

ste

roid

stru

ctur

e is

pro

vide

d in

sec

tion

34 in

the

data

boo

klet

.

Inte

rnat

iona

l-min

dedn

ess:

• Th

e m

isus

e of

dru

gs in

spo

rt is

an

inte

rnat

iona

l pro

blem

.

Theo

ry o

f kno

wle

dge:

• D

evel

opm

ents

in te

chno

logy

hav

e in

crea

sed

the

chan

ces

of p

eopl

e be

ing

caug

ht u

sing

ille

gal s

ubst

ance

s. H

ow d

o ch

ange

s in

tech

nolo

gy in

fluen

ce o

ur

ethi

cal c

hoic

es?

Util

izat

ion:

Syl

labu

s an

d cr

oss-

curri

cula

r lin

ks:

Topi

c 10

.2—

func

tiona

l gro

ups

Aim

s:

• A

im 4

: A v

arie

ty o

f spe

ctro

scop

y te

chni

ques

can

be

used

to id

entif

y ne

wly

de

velo

ped

mol

ecul

es.

• A

im 7

: Com

pute

r dat

abas

es w

ith s

pect

rosc

opy

data

cou

ld b

e us

ed to

con

firm

th

e id

entit

y of

new

ly s

ynth

esiz

ed m

olec

ules

.

• A

im 8

: Dev

elop

men

ts in

tech

nolo

gy h

ave

incr

ease

d th

e ch

ance

s of

peo

ple

bein

g ca

ught

usi

ng il

lega

l sub

stan

ces.

How

do

chan

ges

in te

chno

logy

influ

ence

ou

r eth

ical

cho

ices

?


Assessment

Assessment in the Diploma Programme

GeneralAssessment is an integral part of teaching and learning. The most important aims of assessment in the Diploma Programme are that it should support curricular goals and encourage appropriate student learning. Both external and internal assessments are used in the Diploma Programme. IB examiners mark work produced for external assessment, while work produced for internal assessment is marked by teachers and externally moderated by the IB.

There are two types of assessment identified by the IB.

• Formative assessment informs both teaching and learning. It is concerned with providing accurate and helpful feedback to students and teachers on the kind of learning taking place and the nature of students’ strengths and weaknesses in order to help develop students’ understanding and capabilities. Formative assessment can also help to improve teaching quality, as it can provide information to monitor progress towards meeting the course aims and objectives.

• Summative assessment gives an overview of previous learning and is concerned with measuring student achievement.

The Diploma Programme primarily focuses on summative assessment designed to record student achievement at, or towards the end of, the course of study. However, many of the assessment instruments can also be used formatively during the course of teaching and learning, and teachers are encouraged to do this. A comprehensive assessment plan is viewed as being integral with teaching, learning and course organization. For further information, see the IB Programme standards and practices (2010) document.

The approach to assessment used by the IB is criterion-related, not norm-referenced. This approach to assessment judges students’ work by their performance in relation to identified levels of attainment, and not in relation to the work of other students. For further information on assessment within the Diploma Programme please refer to the publication Diploma Programme assessment: principles and practice (2009).

To support teachers in the planning, delivery and assessment of the Diploma Programme courses, a variety of resources can be found on the OCC or purchased from the IB store (http://store.ibo.org). Additional publications such as specimen papers and markschemes, teacher support materials, subject reports and grade descriptors can also be found on the OCC. Past examination papers as well as markschemes can be purchased from the IB store.

Methods of assessmentThe IB uses several methods to assess work produced by students.

Assessment criteriaAssessment criteria are used when the assessment task is open-ended. Each criterion concentrates on a particular skill that students are expected to demonstrate. An assessment objective describes what students should be able to do, and assessment criteria describe how well they should be able to do it. Using assessment criteria allows discrimination between different answers and encourages a variety of responses.

Assessment in the Diploma Programme

Chemistry guide168

Each criterion comprises a set of hierarchically ordered level descriptors. Each level descriptor is worth one or more marks. Each criterion is applied independently using a best-fit model. The maximum marks for each criterion may differ according to the criterion’s importance. The marks awarded for each criterion are added together to give the total mark for the piece of work.

MarkbandsMarkbands are a comprehensive statement of expected performance against which responses are judged. They represent a single holistic criterion divided into level descriptors. Each level descriptor corresponds to a range of marks to differentiate student performance. A best-fit approach is used to ascertain which particular mark to use from the possible range for each level descriptor.

Analytic markschemesAnalytic markschemes are prepared for those examination questions that expect a particular kind of response and/or a given final answer from students. They give detailed instructions to examiners on how to break down the total mark for each question for different parts of the response.

Marking notesFor some assessment components marked using assessment criteria, marking notes are provided. Marking notes give guidance on how to apply assessment criteria to the particular requirements of a question.

Inclusive assessment arrangementsInclusive assessment arrangements are available for candidates with assessment access requirements. These arrangements enable candidates with diverse needs to access the examinations and demonstrate their knowledge and understanding of the constructs being assessed.

The IB document Candidates with assessment access requirements provides details on all the inclusive assessment arrangements available to candidates with learning support requirements. The IB document Learning diversity and the IB programmes: Special educational needs within the International Baccalaureate programmes outlines the position of the IB with regard to candidates with diverse learning needs in the IB programmes. For candidates affected by adverse circumstances, the IB documents General regulations: Diploma Programme (2011) and the Handbook of procedures for the Diploma Programme provide details on access consideration.

Responsibilities of the schoolThe school is required to ensure that equal access arrangements and reasonable adjustments are provided to candidates with learning support requirements that are in line with the IB documents Candidates with assessment access requirements and Learning diversity and the IB programmes: Special educational needs within the International Baccalaureate programmes.


Assessment

Assessment outline—SL


Component Overall weighting (%)

Approximate weighting of objectives (%)

Duration (hours)

1+2 3

Paper 1 20 10 10 ¾

Paper 2 40 20 20 1¼

Paper 3 20 10 10 1

Internal assessment

20 Covers objectives 1, 2, 3 and 4 10

Chemistry guide170170

Assessment

Assessment outline—HL


Component Overall weighting (%)

Approximate weighting of objectives (%)

Duration (hours)

1+2 3

Paper 1 20 10 10 1

Paper 2 36 18 18 2¼

Paper 3 24 12 12 1¼

Internal assessment

20 Covers objectives 1, 2, 3 and 410


Assessment

External assessment

Detailed markschemes specific to each examination paper are used to assess students.

External assessment details—SL

Paper 1Duration: 3/4 hourWeighting: 20%Marks: 30• 30 multiple-choice questions on core, about 15 of which are common with HL.

• The questions on paper 1 test assessment objectives 1, 2 and 3.

• The use of calculators is not permitted.

• Students will be provided with a periodic table.

• No marks are deducted for incorrect answers.

Paper 2Duration: 1¼ hoursWeighting: 40%Marks: 50• Short-answer and extended-response questions on core material.


• The use of calculators is permitted. (See calculator section on the OCC.)

• A chemistry data booklet is to be provided by the school.

Paper 3Duration: 1 hourWeighting: 20%Marks: 35• This paper will have questions on core and SL option material.

• Section A: one data-based question and several short-answer questions on experimental work.

• Section B: short-answer and extended-response questions from one option.




External assessment

Chemistry guide172

External assessment details—HL

Paper 1Duration: 1 hourWeighting: 20%Marks: 40• 40 multiple-choice questions on core and AHL, about 15 of which are common with SL.


• The use of calculators is not permitted.

• Students will be provided with a periodic table.

• No marks are deducted for incorrect answers.

Paper 2Duration: 2¼ hoursWeighting: 36%Marks: 95• Short-answer and extended-response questions on the core and AHL material.




Paper 3Duration: 1¼ hoursWeighting: 24%Marks: 45• This paper will have questions on core, AHL and option material.

• Section A: one data-based question and several short-answer questions on experimental work.

• Section B: short-answer and extended-response questions from one option.





Assessment

Internal assessment

Purpose of internal assessmentInternal assessment is an integral part of the course and is compulsory for both SL and HL students. It enables students to demonstrate the application of their skills and knowledge, and to pursue their personal interests, without the time limitations and other constraints that are associated with written examinations. The internal assessment should, as far as possible, be woven into normal classroom teaching and not be a separate activity conducted after a course has been taught.

The internal assessment requirements at SL and at HL are the same. This internal assessment section of the guide should be read in conjunction with the internal assessment section of the teacher support materials.

Guidance and authenticityThe work submitted for internal assessment must be the student’s own work. However, it is not the intention that students should decide upon a title or topic and be left to work on the internal assessment component without any further support from the teacher. The teacher should play an important role during both the planning stage and the period when the student is working on the internally assessed work. It is the responsibility of the teacher to ensure that students are familiar with:

• the requirements of the type of work to be internally assessed

• the IB animal experimentation policy

• the assessment criteria—students must understand that the work submitted for assessment must address these criteria effectively.

Teachers and students must discuss the internally assessed work. Students should be encouraged to initiate discussions with the teacher to obtain advice and information, and students must not be penalized for seeking guidance. As part of the learning process, teachers should read and give advice to students on one draft of the work. The teacher should provide oral or written advice on how the work could be improved, but not edit the draft. The next version handed to the teacher must be the final version for submission.

It is the responsibility of teachers to ensure that all students understand the basic meaning and significance of concepts that relate to academic honesty, especially authenticity and intellectual property. Teachers must ensure that all student work for assessment is prepared according to the requirements and must explain clearly to students that the internally assessed work must be entirely their own. Where collaboration between students is permitted, it must be clear to all students what the difference is between collaboration and collusion.

All work submitted to the IB for moderation or assessment must be authenticated by a teacher, and must not include any known instances of suspected or confirmed academic misconduct. Each student must confirm that the work is his or her authentic work and constitutes the final version of that work. Once a student has officially submitted the final version of the work it cannot be retracted. The requirement to confirm the authenticity of work applies to the work of all students, not just the sample work that will be submitted to the IB for the purpose of moderation. For further details refer to the IB publication Academic honesty (2011), The Diploma Programme: From principles into practice (2009) and the relevant articles in General regulations: Diploma Programme (2011).

Internal assessment

Chemistry guide174

Authenticity may be checked by discussion with the student on the content of the work, and scrutiny of one or more of the following:

• the student’s initial proposal

• the first draft of the written work

• the references cited

• the style of writing compared with work known to be that of the student

• the analysis of the work by a web-based plagiarism detection service such as http://www.turnitin.com.

The same piece of work cannot be submitted to meet the requirements of both the internal assessment and the extended essay.

Group workEach investigation is an individual piece of work based on different data collected or measurements generated. Ideally, students should work on their own when collecting data. In some cases, data collected or measurements made can be from a group experiment, provided each student collected his or her own data or made his or her own measurements. In chemistry, in some cases, group data or measurements may be combined to provide enough for individual analysis. Even in this case, each student should have collected and recorded their own data and they should clearly indicate which data are theirs.

It should be made clear to students that all work connected with the investigation should be their own. It is therefore helpful if teachers try to encourage in students a sense of responsibility for their own learning so that they accept a degree of ownership and take pride in their own work.

Time allocationInternal assessment is an integral part of the chemistry course, contributing 20% to the final assessment in the SL and the HL courses. This weighting should be reflected in the time that is allocated to teaching the knowledge, skills and understanding required to undertake the work, as well as the total time allocated to carry out the work.

It is recommended that a total of approximately 10 hours of teaching time for both SL and HL should be allocated to the work. This should include:

• time for the teacher to explain to students the requirements of the internal assessment

• class time for students to work on the internal assessment component and ask questions

• time for consultation between the teacher and each student

• time to review and monitor progress, and to check authenticity.

Safety requirements and recommendationsWhile teachers are responsible for following national or local guidelines, which may differ from country to country, attention should be given to the guidelines below, which were developed for the International Council of Associations for Science Education (ICASE) Safety Committee by The Laboratory Safety Institute (LSI).

Internal assessment

Chemistry guide 175

It is a basic responsibility of everyone involved to make safety and health an ongoing commitment. Any advice given will acknowledge the need to respect the local context, the varying educational and cultural traditions, the financial constraints and the legal systems of differing countries.

The Laboratory Safety Institute’s Laboratory Safety Guidelines ...40 suggestions for a safer lab

Steps Requiring Minimal Expense1. Have a written health, safety and environmental affairs (HS&E) policy statement.

2. Organize a departmental HS&E committee of employees, management, faculty, staff and students that will meet regularly to discuss HS&E issues.

3. Develop an HS&E orientation for all new employees and students.

4. Encourage employees and students to care about their health and safety and that of others.

5. Involve every employee and student in some aspect of the safety program and give each specific responsibilities.

6. Provide incentives to employees and students for safety performance.

7. Require all employees to read the appropriate safety manual. Require students to read the institution’s laboratory safety rules. Have both groups sign a statement that they have done so, understand the contents, and agree to follow the procedures and practices. Keep these statements on file in the department office.

8. Conduct periodic, unannounced laboratory inspections to identify and correct hazardous conditions and unsafe practices. Involve students and employees in simulated OSHA inspections.

9. Make learning how to be safe an integral and important part of science education, your work, and your life.

10. Schedule regular departmental safety meetings for all students and employees to discuss the results of inspections and aspects of laboratory safety.

11. When conducting experiments with hazards or potential hazards, ask yourself these questions:

– What are the hazards?

– What are the worst possible things that could go wrong?

– How will I deal with them?

– What are the prudent practices, protective facilities and equipment necessary to minimize the risk of exposure to the hazards?

12. Require that all accidents (incidents) be reported, evaluated by the departmental safety committee, and discussed at departmental safety meetings.

13. Require every pre-lab/pre-experiment discussion to include consideration of the health and safety aspects.

14. Don’t allow experiments to run unattended unless they are failsafe.

15. Forbid working alone in any laboratory and working without prior knowledge of a staff member.

16. Extend the safety program beyond the laboratory to the automobile and the home.

17. Allow only minimum amounts of flammable liquids in each laboratory.

18. Forbid smoking, eating and drinking in the laboratory.

19. Do not allow food to be stored in chemical refrigerators.

Internal assessment

Chemistry guide176

20. Develop plans and conduct drills for dealing with emergencies such as fire, explosion, poisoning, chemical spill or vapour release, electric shock, bleeding and personal contamination.

21. Require good housekeeping practices in all work areas.

22. Display the phone numbers of the fire department, police department, and local ambulance either on or immediately next to every phone.

23. Store acids and bases separately. Store fuels and oxidizers separately.

24. Maintain a chemical inventory to avoid purchasing unnecessary quantities of chemicals.

25. Use warning signs to designate particular hazards.

26. Develop specific work practices for individual experiments, such as those that should be conducted only in a ventilated hood or involve particularly hazardous materials. When possible most hazardous experiments should be done in a hood.

Steps Requiring Moderate Expense27. Allocate a portion of the departmental budget to safety.

28. Require the use of appropriate eye protection at all times in laboratories and areas where chemicals are transported.

29. Provide adequate supplies of personal protective equipment—safety glasses, goggles, face shields, gloves, lab coats and bench top shields.

30. Provide fire extinguishers, safety showers, eye wash fountains, first aid kits, fire blankets and fume hoods in each laboratory and test or check monthly.

31. Provide guards on all vacuum pumps and secure all compressed gas cylinders.

32. Provide an appropriate supply of first aid equipment and instruction on its proper use.

33. Provide fireproof cabinets for storage of flammable chemicals.

34. Maintain a centrally located departmental safety library:

– “Safety in School Science Labs”, Clair Wood, 1994, Kaufman & Associates, 101 Oak Street, Wellesley, MA 02482

– “The Laboratory Safety Pocket Guide”, 1996, Genium Publisher, One Genium Plaza, Schnectady, NY

– “Safety in Academic Chemistry Laboratories”, ACS, 1155 Sixteenth Street NW, Washington, DC 20036

– “Manual of Safety and Health Hazards in The School Science Laboratory”, “Safety in the School Science Laboratory”, “School Science Laboratories: A guide to Some Hazardous Substances” Council of State Science Supervisors (now available only from LSI.)

– “Handbook of Laboratory Safety”, 4th Edition, CRC Press, 2000 Corporate Boulevard NW, Boca Raton, FL 33431

– “Fire Protection Guide on Hazardous Materials”, National Fire Protection Association, Batterymarch Park, Quincy, MA 02269

– “Prudent Practices in the Laboratory: Handling and Disposal of Hazardous Chemicals”, 2nd Edition, 1995

– “Biosafety in the Laboratory”, National Academy Press, 2101 Constitution Avenue, NW, Washington, DC 20418

– “Learning By Accident”, Volumes 1-3, 1997-2000, The Laboratory Safety Institute, Natick, MA 01760

(All are available from LSI.)

Internal assessment

Chemistry guide 177

35. Remove all electrical connections from inside chemical refrigerators and require magnetic closures.

36. Require grounded plugs on all electrical equipment and install ground fault interrupters (GFIs) where appropriate.

37. Label all chemicals to show the name of the material, the nature and degree of hazard, the appropriate precautions, and the name of the person responsible for the container.

38. Develop a program for dating stored chemicals and for recertifying or discarding them after predetermined maximum periods of storage.

39. Develop a system for the legal, safe and ecologically acceptable disposal of chemical wastes.

40. Provide secure, adequately spaced, well ventilated storage of chemicals.

Using assessment criteria for internal assessmentFor internal assessment, a number of assessment criteria have been identified. Each assessment criterion has level descriptors describing specific achievement levels, together with an appropriate range of marks. The level descriptors concentrate on positive achievement, although for the lower levels failure to achieve may be included in the description.

Teachers must judge the internally assessed work at SL and at HL against the criteria using the level descriptors.

• Assessment criteria are the same for both SL and HL.

• The aim is to find, for each criterion, the descriptor that conveys most accurately the level attained by the student, using the best-fit model. A best-fit approach means that compensation should be made when a piece of work matches different aspects of a criterion at different levels. The mark awarded should be one that most fairly reflects the balance of achievement against the criterion. It is not necessary for every single aspect of a level descriptor to be met for that mark to be awarded.

• When assessing a student’s work, teachers should read the level descriptors for each criterion until they reach a descriptor that most appropriately describes the level of the work being assessed. If a piece of work seems to fall between two descriptors, both descriptors should be read again and the one that more appropriately describes the student’s work should be chosen.

• Where there are two or more marks available within a level, teachers should award the upper marks if the student’s work demonstrates the qualities described to a great extent; the work may be close to achieving marks in the level above. Teachers should award the lower marks if the student’s work demonstrates the qualities described to a lesser extent; the work may be close to achieving marks in the level below.

• Only whole numbers should be recorded; partial marks (fractions and decimals) are not acceptable.

• Teachers should not think in terms of a pass or fail boundary, but should concentrate on identifying the appropriate descriptor for each assessment criterion.

Internal assessment

Chemistry guide178

• The highest level descriptors do not imply faultless performance but should be achievable by a student. Teachers should not hesitate to use the extremes if they are appropriate descriptions of the work being assessed.

• A student who attains a high achievement level in relation to one criterion will not necessarily attain high achievement levels in relation to the other criteria. Similarly, a student who attains a low achievement level for one criterion will not necessarily attain low achievement levels for the other criteria. Teachers should not assume that the overall assessment of the students will produce any particular distribution of marks.

• It is recommended that the assessment criteria be made available to students.


General introductionThe internal assessment requirements are the same for biology, chemistry and physics. The internal assessment, worth 20% of the final assessment, consists of one scientific investigation. The individual investigation should cover a topic that is commensurate with the level of the course of study.

Student work is internally assessed by the teacher and externally moderated by the IB. The performance in internal assessment at both SL and HL is marked against common assessment criteria, with a total mark out of 24.

Note: Any investigation that is to be used to assess students should be specifically designed to match the assessment criteria.

The internal assessment task will be one scientific investigation taking about 10 hours and the write-up should be about 6 to 12 pages long. Investigations exceeding this length will be penalized in the communication criterion as lacking in conciseness.

The practical investigation, with generic criteria, will allow a wide range of practical activities satisfying the varying needs of biology, chemistry and physics. The investigation addresses many of the learner profile attributes well. See section on “Approaches to the teaching of chemistry” for further links.

The task produced should be complex and commensurate with the level of the course. It should require a purposeful research question and the scientific rationale for it. The marked exemplar material in the teacher support materials will demonstrate that the assessment will be rigorous and of the same standard as the assessment in the previous courses.

Some of the possible tasks include:

• a hands-on laboratory investigation

• using a spreadsheet for analysis and modelling

• extracting data from a database and analysing it graphically

• producing a hybrid of spreadsheet/database work with a traditional hands-on investigation

• using a simulation provided it is interactive and open-ended.

Some tasks may consist of relevant and appropriate qualitative work combined with quantitative work.

Internal assessment

Chemistry guide 179

The tasks include the traditional hands-on practical investigations as in the previous course. The depth of treatment required for hands-on practical investigations is unchanged from the previous internal assessment and will be shown in detail in the teacher support materials. In addition, detailed assessment of specific aspects of hands-on practical work will be assessed in the written papers as detailed in the relevant topic(s) in the “Syllabus content” section of the guide.

The task will have the same assessment criteria for SL and HL. The five assessment criteria are personal engagement, exploration, analysis, evaluation and communication.

Internal assessment details

Internal assessment componentDuration: 10 hoursWeighting: 20%• Individual investigation

• This investigation covers assessment objectives 1, 2, 3 and 4.

Internal assessment criteriaThe new assessment model uses five criteria to assess the final report of the individual investigation with the following raw marks and weightings assigned:

Personal engagement

Exploration Analysis Evaluation Communication Total

2 (8%) 6 (25%) 6 (25%) 6 (25%) 4 (17%) 24 (100%)

Levels of performance are described using multiple indicators per level. In many cases the indicators occur together in a specific level, but not always. Also, not all indicators are always present. This means that a candidate can demonstrate performances that fit into different levels. To accommodate this, the IB assessment models use markbands and advise examiners and teachers to use a best-fit approach in deciding the appropriate mark for a particular criterion.

Teachers should read the guidance on using markbands shown above in the section called “Using assessment criteria for internal assessment” before starting to mark. It is also essential to be fully acquainted with the marking of the exemplars in the teacher support material. The precise meaning of the command terms used in the criteria can be found in the glossary of the subject guides.

Personal engagementThis criterion assesses the extent to which the student engages with the exploration and makes it their own. Personal engagement may be recognized in different attributes and skills. These could include addressing personal interests or showing evidence of independent thinking, creativity or initiative in the designing, implementation or presentation of the investigation.

Internal assessment

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Mark Descriptor

0 The student’s report does not reach a standard described by the descriptors below.

1 The evidence of personal engagement with the exploration is limited with little independent thinking, initiative or creativity.

The justification given for choosing the research question and/or the topic under investigation does not demonstrate personal significance, interest or curiosity.

There is little evidence of personal input and initiative in the designing, implementation or presentation of the investigation.

2 The evidence of personal engagement with the exploration is clear with significant independent thinking, initiative or creativity.

The justification given for choosing the research question and/or the topic under investigation demonstrates personal significance, interest or curiosity.

There is evidence of personal input and initiative in the designing, implementation or presentation of the investigation.

ExplorationThis criterion assesses the extent to which the student establishes the scientific context for the work, states a clear and focused research question and uses concepts and techniques appropriate to the Diploma Programme level. Where appropriate, this criterion also assesses awareness of safety, environmental, and ethical considerations.

Mark Descriptor


1–2 The topic of the investigation is identified and a research question of some relevance is stated but it is not focused.

The background information provided for the investigation is superficial or of limited relevance and does not aid the understanding of the context of the investigation.

The methodology of the investigation is only appropriate to address the research question to a very limited extent since it takes into consideration few of the significant factors that may influence the relevance, reliability and sufficiency of the collected data.

The report shows evidence of limited awareness of the significant safety, ethical or environmental issues that are relevant to the methodology of the investigation*.

3–4 The topic of the investigation is identified and a relevant but not fully focused research question is described.

The background information provided for the investigation is mainly appropriate and relevant and aids the understanding of the context of the investigation.

The methodology of the investigation is mainly appropriate to address the research question but has limitations since it takes into consideration only some of the significant factors that may influence the relevance, reliability and sufficiency of the collected data.

The report shows evidence of some awareness of the significant safety, ethical or environmental issues that are relevant to the methodology of the investigation.*

Internal assessment

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Mark Descriptor

5–6 The topic of the investigation is identified and a relevant and fully focused research question is clearly described.

The background information provided for the investigation is entirely appropriate and relevant and enhances the understanding of the context of the investigation.

The methodology of the investigation is highly appropriate to address the research question because it takes into consideration all, or nearly all, of the significant factors that may influence the relevance, reliability and sufficiency of the collected data.

The report shows evidence of full awareness of the significant safety, ethical or environmental issues that are relevant to the methodology of the investigation.*

* This indicator should only be applied when appropriate to the investigation. See exemplars in TSM.

AnalysisThis criterion assesses the extent to which the student’s report provides evidence that the student has selected, recorded, processed and interpreted the data in ways that are relevant to the research question and can support a conclusion.

Mark Descriptor


1–2 The report includes insufficient relevant raw data to support a valid conclusion to the research question.

Some basic data processing is carried out but is either too inaccurate or too insufficient to lead to a valid conclusion.

The report shows evidence of little consideration of the impact of measurement uncertainty on the analysis.

The processed data is incorrectly or insufficiently interpreted so that the conclusion is invalid or very incomplete.

3–4 The report includes relevant but incomplete quantitative and qualitative raw data that could support a simple or partially valid conclusion to the research question.

Appropriate and sufficient data processing is carried out that could lead to a broadly valid conclusion but there are significant inaccuracies and inconsistencies in the processing.

The report shows evidence of some consideration of the impact of measurement uncertainty on the analysis.

The processed data is interpreted so that a broadly valid but incomplete or limited conclusion to the research question can be deduced.

5–6 The report includes sufficient relevant quantitative and qualitative raw data that could support a detailed and valid conclusion to the research question.

Appropriate and sufficient data processing is carried out with the accuracy required to enable a conclusion to the research question to be drawn that is fully consistent with the experimental data.

The report shows evidence of full and appropriate consideration of the impact of measurement uncertainty on the analysis.

The processed data is correctly interpreted so that a completely valid and detailed conclusion to the research question can be deduced.

Internal assessment

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EvaluationThis criterion assesses the extent to which the student’s report provides evidence of evaluation of the investigation and the results with regard to the research question and the accepted scientific context.

Mark Descriptor


1–2 A conclusion is outlined which is not relevant to the research question or is not supported by the data presented.

The conclusion makes superficial comparison to the accepted scientific context.

Strengths and weaknesses of the investigation, such as limitations of the data and sources of error, are outlined but are restricted to an account of the practical or procedural issues faced.

The student has outlined very few realistic and relevant suggestions for the improvement and extension of the investigation.

3–4 A conclusion is described which is relevant to the research question and supported by the data presented.

A conclusion is described which makes some relevant comparison to the accepted scientific context.

Strengths and weaknesses of the investigation, such as limitations of the data and sources of error, are described and provide evidence of some awareness of the methodological issues* involved in establishing the conclusion.

The student has described some realistic and relevant suggestions for the improvement and extension of the investigation.

5–6 A detailed conclusion is described and justified which is entirely relevant to the research question and fully supported by the data presented.

A conclusion is correctly described and justified through relevant comparison to the accepted scientific context.

Strengths and weaknesses of the investigation, such as limitations of the data and sources of error, are discussed and provide evidence of a clear understanding of the methodological issues* involved in establishing the conclusion.

The student has discussed realistic and relevant suggestions for the improvement and extension of the investigation.

*See exemplars in TSM for clarification.

Internal assessment

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CommunicationThis criterion assesses whether the investigation is presented and reported in a way that supports effective communication of the focus, process and outcomes.

Mark Descriptor


1–2 The presentation of the investigation is unclear, making it difficult to understand the focus, process and outcomes.

The report is not well structured and is unclear: the necessary information on focus, process and outcomes is missing or is presented in an incoherent or disorganized way.

The understanding of the focus, process and outcomes of the investigation is obscured by the presence of inappropriate or irrelevant information.

There are many errors in the use of subject specific terminology and conventions*.

3–4 The presentation of the investigation is clear. Any errors do not hamper understanding of the focus, process and outcomes.

The report is well structured and clear: the necessary information on focus, process and outcomes is present and presented in a coherent way.

The report is relevant and concise thereby facilitating a ready understanding of the focus, process and outcomes of the investigation.

The use of subject specific terminology and conventions is appropriate and correct. Any errors do not hamper understanding.

*For example, incorrect/missing labelling of graphs, tables, images; use of units, decimal places. For issues of referencing and citations refer to the “Academic honesty” section.

Rationale for practical workAlthough the requirements for IA are centred on the investigation, the different types of practical activities that a student may engage in serve other purposes, including:

• illustrating, teaching and reinforcing theoretical concepts

• developing an appreciation of the essential hands-on nature of much scientific work

• developing an appreciation of scientists’ use of secondary data from databases

• developing an appreciation of scientists’ use of modelling

• developing an appreciation of the benefits and limitations of scientific methodology.

Internal assessment

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Practical scheme of workThe practical scheme of work (PSOW) is the practical course planned by the teacher and acts as a summary of all the investigative activities carried out by a student. Students at SL and HL in the same subject may carry out some of the same investigations.

Syllabus coverageThe range of practical work carried out should reflect the breadth and depth of the subject syllabus at each level, but it is not necessary to carry out an investigation for every syllabus topic. However, all students must participate in the group 4 project and the IA investigation.

Planning your practical scheme of workTeachers are free to formulate their own practical schemes of work by choosing practical activities according to the requirements outlined. Their choices should be based on:

• subjects, levels and options taught

• the needs of their students

• available resources

• teaching styles.

Each scheme must include some complex experiments that make greater conceptual demands on students. A scheme made up entirely of simple experiments, such as ticking boxes or exercises involving filling in tables, will not provide an adequate range of experience for students.

Teachers are encouraged to use the online curriculum centre (OCC) to share ideas about possible practical activities by joining in the discussion forums and adding resources in the subject home pages.

FlexibilityThe practical programme is flexible enough to allow a wide variety of practical activities to be carried out. These could include:

• short labs or projects extending over several weeks

• computer simulations

• using databases for secondary data

• developing and using models

• data-gathering exercises such as questionnaires, user trials and surveys

• data-analysis exercises

• fieldwork.

Practical work documentationDetails of the practical scheme of work are recorded on Form 4/PSOW provided in the Handbook of procedures. A copy of the class 4/PSOW form must be included with any sample set sent for moderation. For an SL only class or an HL only class, only one 4/PSOW is required, but for a mixed SL/HL class, separate 4/PSOW forms are required for SL and HL.

Internal assessment

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Time allocation for practical workThe recommended teaching times for all Diploma Programme courses are 150 hours at SL and 240 hours at HL. Students at SL are required to spend 40 hours, and students at HL 60 hours, on practical activities (excluding time spent writing up work). These times include 10 hours for the group 4 project and 10 hours for the internal assessment investigation. (Only 2–3 hours of investigative work can be carried out after the deadline for submitting work to the moderator and still be counted in the total number of hours for the practical scheme of work.)


Assessment

The group 4 project

The group 4 project is an interdisciplinary activity in which all Diploma Programme science students must participate. The intention is that students from the different group 4 subjects analyse a common topic or problem. The exercise should be a collaborative experience where the emphasis is on the processes involved in, rather than the products of, such an activity.

In most cases students in a school would be involved in the investigation of the same topic. Where there are large numbers of students, it is possible to divide them into several smaller groups containing representatives from each of the science subjects. Each group may investigate the same topic or different topics—that is, there may be several group 4 projects in the same school.

Students studying environmental systems and societies are not required to undertake the group 4 project.

Summary of the group 4 projectThe group 4 project is a collaborative activity where students from different group 4 subjects work together on a scientific or technological topic, allowing for concepts and perceptions from across the disciplines to be shared in line with aim 10—that is, to “develop an understanding of the relationships between scientific disciplines and their influence on other areas of knowledge”. The project can be practically or theoretically based. Collaboration between schools in different regions is encouraged.

The group 4 project allows students to appreciate the environmental, social and ethical implications of science and technology. It may also allow them to understand the limitations of scientific study, for example, the shortage of appropriate data and/or the lack of resources. The emphasis is on interdisciplinary cooperation and the processes involved in scientific investigation, rather than the products of such investigation.

The choice of scientific or technological topic is open but the project should clearly address aims 7, 8 and 10 of the group 4 subject guides.

Ideally, the project should involve students collaborating with those from other group 4 subjects at all stages. To this end, it is not necessary for the topic chosen to have clearly identifiable separate subject components. However, for logistical reasons, some schools may prefer a separate subject “action” phase (see the following “Project stages” section).

Project stagesThe 10 hours allocated to the group 4 project, which are part of the teaching time set aside for developing the practical scheme of work, can be divided into three stages: planning, action and evaluation.

PlanningThis stage is crucial to the whole exercise and should last about two hours.

• The planning stage could consist of a single session, or two or three shorter ones.

• This stage must involve all group 4 students meeting to “brainstorm” and discuss the central topic, sharing ideas and information.

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• The topic can be chosen by the students themselves or selected by the teachers.

• Where large numbers of students are involved, it may be advisable to have more than one mixed subject group.

After selecting a topic or issue, the activities to be carried out must be clearly defined before moving from the planning stage to the action and evaluation stages.

A possible strategy is that students define specific tasks for themselves, either individually or as members of groups, and investigate various aspects of the chosen topic. At this stage, if the project is to be experimentally based, apparatus should be specified so that there is no delay in carrying out the action stage. Contact with other schools, if a joint venture has been agreed, is an important consideration at this time.

ActionThis stage should last around six hours and may be carried out over one or two weeks in normal scheduled class time. Alternatively, a whole day could be set aside if, for example, the project involves fieldwork.

• Students should investigate the topic in mixed-subject groups or single subject groups.

• There should be collaboration during the action stage; findings of investigations should be shared with other students within the mixed/single-subject group. During this stage, in any practically based activity, it is important to pay attention to safety, ethical and environmental considerations.

Note: Students studying two group 4 subjects are not required to do two separate action phases.

EvaluationThe emphasis during this stage, for which two hours are probably necessary, is on students sharing their findings, both successes and failures, with other students. How this is achieved can be decided by the teachers, the students or jointly.

• One solution is to devote a morning, afternoon or evening to a symposium where all the students, as individuals or as groups, give brief presentations.

• Alternatively, the presentation could be more informal and take the form of a science fair where students circulate around displays summarizing the activities of each group.

The symposium or science fair could also be attended by parents, members of the school board and the press. This would be especially pertinent if some issue of local importance has been researched. Some of the findings might influence the way the school interacts with its environment or local community.

Addressing aims 7 and 8Aim 7: “develop and apply 21st century communication skills in the study of science.”

Aim 7 may be partly addressed at the planning stage by using electronic communication within and between schools. It may be that technology (for example, data logging, spreadsheets, databases and so on) will be used in the action phase and certainly in the presentation/evaluation stage (for example, use of digital images, presentation software, websites, digital video and so on).

Aim 8: “become critically aware, as global citizens, of the ethical implications of using science and technology.”

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Addressing the international dimensionThere are also possibilities in the choice of topic to illustrate the international nature of the scientific endeavour and the increasing cooperation required to tackle global issues involving science and technology. An alternative way to bring an international dimension to the project is to collaborate with a school in another region.

Types of projectWhile addressing aims 7, 8 and 10 the project must be based on science or its applications. The project may have a hands-on practical action phase or one involving purely theoretical aspects. It could be undertaken in a wide range of ways:

• designing and carrying out a laboratory investigation or fieldwork.

• carrying out a comparative study (experimental or otherwise) in collaboration with another school.

• collating, manipulating and analysing data from other sources, such as scientif ic journals, environmental organizations, science and technology industries and government reports.

• designing and using a model or simulation.

• contributing to a long-term project organized by the school.

Logistical strategiesThe logistical organization of the group 4 project is often a challenge to schools. The following models illustrate possible ways in which the project may be implemented.

Models A, B and C apply within a single school, and model D relates to a project involving collaboration between schools.

Model A: mixed-subject groups and one topicSchools may adopt mixed-subject groups and choose one common topic. The number of groups will depend on the number of students.

Model B: mixed-subject groups adopting more than one topicSchools with large numbers of students may choose to do more than one topic.

Model C: single-subject groupsFor logistical reasons some schools may opt for single-subject groups, with one or more topics in the action phase. This model is less desirable as it does not show the mixed subject collaboration in which many scientists are involved.

Model D: collaboration with another schoolThe collaborative model is open to any school. To this end, the IB provides an electronic collaboration board on the OCC where schools can post their project ideas and invite collaboration from other schools. This could range from merely sharing evaluations for a common topic to a full-scale collaborative venture at all stages.

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For schools with few Diploma Programme (course) students it is possible to work with non-Diploma Programme or non-group 4 students or undertake the project once every two years. However, these schools are encouraged to collaborate with another school. This strategy is also recommended for individual students who may not have participated in the project, for example, through illness or because they have transferred to a new school where the project has already taken place.

TimingThe 10 hours that the IB recommends be allocated to the project may be spread over a number of weeks. The distribution of these hours needs to be taken into account when selecting the optimum time to carry out the project. However, it is possible for a group to dedicate a period of time exclusively to project work if all/most other schoolwork is suspended.

Year 1In the first year, students’ experience and skills may be limited and it would be inadvisable to start the project too soon in the course. However, doing the project in the final part of the first year may have the advantage of reducing pressure on students later on. This strategy provides time for solving unexpected problems.

Year 1–Year 2The planning stage could start, the topic could be decided upon, and provisional discussion in individual subjects could take place at the end of the first year. Students could then use the vacation time to think about how they are going to tackle the project and would be ready to start work early in the second year.

Year 2Delaying the start of the project until some point in the second year, particularly if left too late, increases pressure on students in many ways: the schedule for finishing the work is much tighter than for the other options; the illness of any student or unexpected problems will present extra difficulties. Nevertheless, this choice does mean students know one another and their teachers by this time, have probably become accustomed to working in a team and will be more experienced in the relevant fields than in the first year.

Combined SL and HLWhere circumstances dictate that the project is only carried out every two years, HL beginners and more experienced SL students can be combined.

Selecting a topicStudents may choose the topic or propose possible topics and the teacher then decides which one is the most viable based on resources, staff availability and so on. Alternatively, the teacher selects the topic or proposes several topics from which students make a choice.

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Student selectionStudents are likely to display more enthusiasm and feel a greater sense of ownership for a topic that they have chosen themselves. A possible strategy for student selection of a topic, which also includes part of the planning stage, is outlined here. At this point, subject teachers may provide advice on the viability of proposed topics.

• Identify possible topics by using a questionnaire or a survey of students.

• Conduct an initial “brainstorming” session of potential topics or issues.

• Discuss, briefly, two or three topics that seem interesting.

• Select one topic by consensus.

• Students make a list of potential investigations that could be carried out. All students then discuss issues such as possible overlap and collaborative investigations.

A reflective statement written by each student on their involvement in the group 4 project must be included on the coversheet for each internal assessment investigation. See Handbook of procedures for more details.


Appendices

Glossary of command terms

Command terms for chemistryStudents should be familiar with the following key terms and phrases used in examination questions, which are to be understood as described below. Although these terms will be used frequently in examination questions, other terms may be used to direct students to present an argument in a specific way.

These command terms indicate the depth of treatment required.

Assessment objective 1

Command term Definition

Classify Arrange or order by class or category.

Define Give the precise meaning of a word, phrase, concept or physical quantity.

Draw Represent by means of a labelled, accurate diagram or graph, using a pencil. A ruler (straight edge) should be used for straight lines. Diagrams should be drawn to scale. Graphs should have points correctly plotted (if appropriate) and joined in a straight line or smooth curve.

Label Add labels to a diagram.

List Give a sequence of brief answers with no explanation.

Measure Obtain a value for a quantity.

State Give a specific name, value or other brief answer without explanation or calculation.



Annotate Add brief notes to a diagram or graph.

Apply Use an idea, equation, principle, theory or law in relation to a given problem or issue.

Calculate Obtain a numerical answer showing the relevant stages in the working.

Describe Give a detailed account.

Distinguish Make clear the differences between two or more concepts or items.

Estimate Obtain an approximate value.

Formulate Express precisely and systematically the relevant concept(s) or argument(s).


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Identify Provide an answer from a number of possibilities.

Outline Give a brief account or summary.



Analyse Break down in order to bring out the essential elements or structure.

Comment Give a judgment based on a given statement or result of a calculation.

Compare Give an account of the similarities between two (or more) items or situations, referring to both (all) of them throughout.

Compare and contrast

Give an account of similarities and differences between two (or more) items or situations, referring to both (all) of them throughout.

Construct Display information in a diagrammatic or logical form.

Deduce Reach a conclusion from the information given.

Demonstrate Make clear by reasoning or evidence, illustrating with examples or practical application.

Derive Manipulate a mathematical relationship to give a new equation or relationship.

Design Produce a plan, simulation or model.

Determine Obtain the only possible answer.

Discuss Offer a considered and balanced review that includes a range of arguments, factors or hypotheses. Opinions or conclusions should be presented clearly and supported by appropriate evidence.

Evaluate Make an appraisal by weighing up the strengths and limitations.

Examine Consider an argument or concept in a way that uncovers the assumptions and interrelationships of the issue.

Explain Give a detailed account including reasons or causes.

Explore Undertake a systematic process of discovery.

Interpret Use knowledge and understanding to recognize trends and draw conclusions from given information.

Justify Give valid reasons or evidence to support an answer or conclusion.

Predict Give an expected result.

Show Give the steps in a calculation or derivation.

Sketch Represent by means of a diagram or graph (labelled as appropriate). The sketch should give a general idea of the required shape or relationship, and should include relevant features.


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Solve Obtain the answer(s) using algebraic and/or numerical and/or graphical methods.

Suggest Propose a solution, hypothesis or other possible answer.


Appendices

Bibliography

This bibliography lists the principal works used to inform the curriculum review. It is not an exhaustive list and does not include all the literature available: judicious selection was made in order to better advise and guide teachers. This bibliography is not a list of recommended textbooks.

Rhoton, J. 2010. Science Education Leadership: Best Practices for the New Century. Arlington, Virginia, USA. National Science Teachers Association Press.

Masood, E. 2009. Science & Islam: A History. London, UK. Icon Books.

Roberts, B. 2009. Educating for Global Citizenship: A Practical Guide for Schools. Cardiff, UK. International Baccalaureate Organization.

Martin, J. 2006. The Meaning of the 21st Century: A vital blueprint for ensuring our future. London, UK. Eden Project Books.

Gerzon, M. 2010. Global Citizens: How our vision of the world is outdated, and what we can do about it. London, UK. Rider Books.

Haydon, G. 2006. Education, Philosophy & the Ethical Environment. Oxon/New York, USA. Routledge.

Anderson, LW et al. 2001. A Taxonomy for Learning, Teaching, and Assessing: A Revision of Bloom’s Taxonomy of Educational Objectives. New York, USA. Addison Wesley Longman, Inc.

Hattie, J. 2009. Visible learning: A synthesis of over 800 meta-analyses relating to achievement. Oxon/New York, USA. Routledge.

Petty, G. 2009. Evidence-based Teaching: A practical approach (2nd edition). Cheltenham, UK. Nelson Thornes Ltd.

Andain, I and Murphy, G. 2008. Creating Lifelong Learners: Challenges for Education in the 21st Century. Cardiff, UK. International Baccalaureate Organization.

Jewkes, J, Sawers, D and Stillerman, R. 1969. The Sources of Invention (2nd edition). New York, USA. W.W. Norton & Co.

Lawson, B. 2005. How Designers Think: The design process demystified (4th edition). Oxford, UK. Architectural Press.

Douglas, H. 2009. Science, Policy, and the Value-Free Ideal. Pittsburgh, Pennsylvania, USA. University of Pittsburgh Press.

Aikenhead, G and Michell, H. 2011. Bridging Cultures: Indigenous and Scientific Ways of Knowing Nature. Toronto, Canada. Pearson Canada.

Winston, M and Edelbach, R. 2012. Society, Ethics, and Technology (4th edition). Boston, Massachusetts, USA. Wadsworth CENGAGE Learning.

Brian Arthur, W. 2009. The Nature of Technology. London, UK. Penguin Books.

Headrick, D. 2009. Technology: A World History. Oxford, UK. Oxford University Press.

Popper, KR. 1980. The Logic of Scientific Discovery (4th revised edition). London, UK. Hutchinson.

Trefil, J. 2008. Why Science?. New York/Arlington, USA. NSTA Press & Teachers College Press.

Bibliography

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Kuhn, TS. 1996. The Structure of Scientific Revolutions (3rd edition). Chicago, Illinois, USA. The University of Chicago Press.

Khine, MS, (ed). 2012. Advances in Nature of Science Research: Concepts and Methodologies. Bahrain. Springer.

Spier, F. 2010. Big History and the Future of Humanity. Chichester, UK. Wiley-Blackwell.

Stokes Brown, C. 2007. Big History: From the Big Bang to the Present. New York, USA. The New Press.

Swain, H, (ed). 2002. Big Questions in Sciences. London, UK. Vintage.

Roberts, RM. 1989. Serendipity: Accidental Discoveries in Science. Chichester, UK. Wiley Science Editions.

Ehrlich, R. 2001. Nine crazy ideas in science. Princeton, New Jersey, USA. Princeton University Press.

Lloyd, C. 2012. What on Earth Happened?: The Complete Story of the Planet, Life and People from the Big Bang to the Present Day. London, UK. Bloomsbury Publishing.

Trefil, J and Hazen, RM. 2010. Sciences: An integrated Approach (6th edition). Chichester, UK. Wiley.

ICASE. 2010. Innovation in Science & Technology Education: Research, Policy, Practice. Tartu, Estonia. ICASE/UNESCO/University of Tartu.

American Association for the Advancement of Science. 1990. Science for all Americans online. Washington, USA. http://www.project2061.org/publications/sfaa/online/sfaatoc.htm.

The Geological Society of America. 2012. Nature of Science and the Scientific Method. Boulder, Colorado, USA. http://www.geosociety.org/educate/naturescience.pdf

Big History Project. 2011. Big History: An Introduction to Everything. http://www.bighistoryproject.com

Nuffield Foundation. 2012. How science works. London, UK. http://www.nuffieldfoundation.org/practical-physics/how-science-works.

University of California Museum of Paleontology. 2013. Understanding Science. Berkeley, California, USA. 1 February 2013. http://www.understandingscience.org.

Collins, S, Osborne, J, Ratcliffe, M, Millar, R, and Duschl, R. 2012, What ‘ideas-about-science’ should be taught in school science? A Delphi study of the ‘expert’ community. St. Louis, Missouri, USA. National Association for Research in Science Teaching (NARST).

TIMSS (The Trends in International Mathematics and Science Study). 1 February 2013. http://timssandpirls.bc.edu.

PISA (Programme for International Student Assessment). 1 February 2013. http://www.oecd.org/pisa.

ROSE (The Relevance of Science Education). 1 February 2013. http://roseproject.no/.

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