Introduction to

ChemistryChapter 1

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Why Study Chemistry: An Introduction

• Chemistry affects almost all aspects of life.

• Chemistry is a very broad area of study with much specialized knowledge.

• Studying chemistry involves understanding new concepts and developing effective problem solving strategies.

• Research in chemistry has contributed to many advances in modern life.– Materials, energy, medicine, the environment. 2

I.) Materials

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• Chemists are constantly looking for new reactions that can be used to create new materials.

• Plastics and many other artificial materials are made from combining simple compounds to make more complex ones.

Depiction of two "Fullerene Nano-gears" with multiple teeth.

II.) Energy

• As more countries modernize there will be a greater need for energy.

• Chemists play a key role in finding ways to create, conserve, and store energy.

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III.) Medicine and Biotechnology

• Advancements in treatments of diseases results from new drug therapies.

• Development of new drugs are a direct result of work done by chemists.

Taxol

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IV.) The Environment

• Materials produced by chemists have produced unintended consequences for our environment.

• Pollutants can be identified and prevented from escaping into the environment. 6

What is a pollutant?

• The identification of pollutants and the prevention of pollution is carried out by mainly by chemists.

• Chemists can also have advisory roles in drafting legislation preventing pollution.

A material found in the air, water, or soil that is harmful to humans or other organisms.

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Class problem

Use lead as an example to explain the meaning of the term pollutant.

(Problem set #5)

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What is Chemistry

The study of the composition, structure and properties of matter, and the changes it undergoes.

• Anything that has mass and occupies space.

This include things seen and unseen. We will come back to this discussion of matter later.

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Examples ofmatter.

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Because matter is everywhere and matter changes constantly,chemistry is occurring all around all the time.

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Chemistry is a very broad area of study.

• Because chemistry is involved in all aspects of existence it covers quite an expansive range of knowledge.

• It is convenient to divide chemistry into subgroups each containing specialized knowledge.

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Class Problem

What are the five subdisciplines of chemistry? Describe them.

(Problem set #6)

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Areas of Study

CHEMISTRY

Organic chemistry

Inorganic Chemistry

BiochemistryAnalytical Chemistry

Physical Chemistry

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? ? ? ? ?

What are these Areas

Organic ChemistryThe study of all chemicals containing carbon

Inorganic Chemistry

The study of chemicals that, in general, do not contain carbon.

Biochemistry The study of processes that take place in organisms.

Analytical Chemistry

The area of study that focuses on the composition of matter.

Physical ChemistryThe area of study that deals with the mechanisms, the rate, and the energy transfer that occurs when matter undergoes change. 15

Pure vs. Applied Chemistry • Pure chemistry is more theoretical

chemistry.– Research conducted for the sole purpose of

increasing knowledge.– Basic research.

• Applied chemistry seeks practical applications.– Research carried out to solve a particular

problem.

• One can lead to the other. 16

Pure chemistry leading to practical applications.• Carothers took a

proposal made by a German chemist on the structure of silk and cotton and through experimentation came up with nylon.

• Also discovered neoprene.

Wallace CarothersAmerican Chemist

1896 - 193717

Applied chemistry can lead to advances in technology: nanotechnology

• This is the study of controlling matter at the atomic and molecular levels.

• Nanotechnology deals with structures in the range of 1 – 100 nm.

A carbon nanotube

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Technology: The means bywhich a society provides its members with those things needed and desired. (p.9)

Possible applications for nanotechnology

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Class problem

Describe the relationship between pure chemistry and applied chemistry.

(Problem set #7)

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An Experimental Approach to Science

• Alchemy laid the ground work for modern chemistry.– It was not systematic

enough.

• Experimental data that could be repeated set chemistry on its modern footing. 21

The Scientific Method

• The scientific method provides a very systematic approach to studying a phenomenon.

• There are four basic steps to the scientific method: make observations, form hypothesis, run experiments, develop theories.

A logical, systematic approach to the solution of a scientific problem.

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Class problem

Which of the following is not a part of the scientific method: hypothesis, experiment, guess, theory?

(Problem set #8)

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Steps in the Scientific Method

Observation

Use of one’s senses to Use of one’s senses to obtain info.obtain info.

Hypothesis

A proposed explanation A proposed explanation for an observationfor an observation

Experiment

A procedure that is used A procedure that is used to test a hypothesisto test a hypothesis

TheoryA well-tested explanation for a A well-tested explanation for a broad set of observationsbroad set of observations

Scientific LawA concise statement that summarizes A concise statement that summarizes the results of many observations the results of many observations and experimentsand experiments

Question: What happens when the “right” Question: What happens when the “right” results are not obtained in an experiment? results are not obtained in an experiment? Is the experiment a failure?Is the experiment a failure?

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Conducting an Experiment

• Experiments are designed to show the connection between one variable and another as postulated in the hypothesis.

• Any factors that may interfere with this relationship must be minimized or eliminated if possible.

Manipulated VariableIndependent Variable

Responding VariableDependent Variable

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Class problem

What was (were) the manipulated variable(s)?

What was (were) the responding variable (s)?

In our 1st experiment: (Problem set #9)

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Collaboration and Communication

• Repeated confirmation of a hypothesis makes it more creditable.

• Collaboration and communication allows more minds to examine and work on a hypothesis and improve it.

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Class problem

When can a hypothesis become a theory?

(Problem set #10)

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Problem Solving in Chemistry

• Chemistry requires the ability to solve problems, numeric and conceptual.

• Solving problems in chemistry require some systematic approach.– Visuals are helpful in

solving problems.29

Solving Numeric Problems

• Step 1: Analyze. Identify what is known and what is unknown. Create a plan/strategy to get from known to unknown.

• Step 2: Calculate. This is usually the easiest part.

• Part 3. Evaluate. Check that your answers “make sense.”

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Basic Math Concepts to Review• Fractions

– Add/ Subtract– Multiply/ Divide– Equivalent fractions

• Percentages– Calculating percentages

• Algebra• Setting up/ solving simple equations

• Integers– Adding/ Subtracting 31

Introduction to

ChemistryChapter 1

The End32

Attendance ProblemAttendance Problem

Describe a chemical that you use everyday and explain what the world would be like without it. (Problem set #1)

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Attendance ProblemAttendance Problem

Would a geologist ask a biochemist to help identify the minerals in a rock? Why?

(Problem set #2)

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Attendance ProblemAttendance Problem

Describe the difference between the microscopic world and the macroscopic world. Give an example of something from each one.

(Problem Set #3)

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Attendance ProblemAttendance Problem

What type of chemist might study how an athlete uses energy during a competition? Give a reason for your answer.

(Problem Set #4)

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Homework Answers

• P.35

71.) 300 miles

• P. 36

81.) 144,000 eggs

82.) The number of gallons per barrel

83a.) $1.00 per package

83b.) The number of envelopes per package.

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