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Shelley College Science Department
Revision Support Book
Science A -‐ Chemistry
Name:_________________________ Chemistry Feedback:
Chemistry Checklist Unit Content Red/Amber/Green Update R/A/G To improve I need to… C1.1 Atoms and the periodic table
Chemical reactions
C1.2 Limestone and building materials
C1.3 Metals and their uses Extracting metals Alloys
C1.4 Crude oil and fuels Hydrocarbons Hydrocarbon fuels
C1.5 Cracking and polymers Ethanol Recycling and plastics
C1.6 Vegetable oils Emulsions Saturated and unsaturated oils
C1.7 The Earth’s crust The Earth’s atmosphere
Chemistry Activities – you may be asked to do some of these in class! You can also do them independently.
1. Create a mind map on a piece of A3 paper which shows the key points of each topic C1.1 to C1.7.
2. Create atomic structure snap. On one card draw the atomic structure and on another card write the name of an element OR the group OR the number of shells. Do two sets for the fist 20 elements and shuffle together. Play to see how quickly you can recognize, element, group or shells.
3. In pairs use the Discovery Channel website to make a crossword for another group to complete. Make sure you spell your words correctly. Can you come up with a good question? http://puzzlemaker.discoveryeducation.com/CrissCrossSetupForm.asp
4. Use the GCSE bitesize revision app (available on apple and android) to create a revision timetable and answer questions on biology.
5. Make a 3 minute video with your friends on a selected chemistry topic. You could write a script use mini whiteboards or props and deliver to the whole class.
6. Make some detailed notes from the Kerboodle text book on an area you are unsure of. Ask your teacher for more examples of exam questions for this topic.
7. Command words-‐ look through all the exam questions in this revision booklet. Can you pick out the common words used to start a question eg “Explain”. What clues do you think these words are giving you about the answer you need to give. Brainstorm a glossary in groups and feedback.
8. Play chemistry word bingo. In pairs write down all the words you would expect to hear when you
describe a particular topic. Then ask another pair to tell you as much as they can and give them a point each time the mention one of the words in the bingo. If they get them all shout BINGO! Swap over and try the other way round!
9. Match the “mark-‐scheme” – you are given cards with questions and “mark-‐schemes” on them. Can you match the questions with the correct “mark-‐scheme” in the shortest time! Write down the full answers in your book.
Chemistry extended response questions – answer these questions in your book or on paper. These questions are assessed for spelling, punctuation and grammar. You should also give as much detail in your answers as you can. In these questions you will be assessed on using good English, organising information clearly and using specialist terms where appropriate. 1) For the last 200 million years the amount of carbon dioxide in the atmosphere has remained almost the same.
• Describe the natural processes which remove carbon dioxide from the atmosphere. (4 marks)
2) There are millions of plastic bags in use. After use most of these plastic bags are buried in landfill sites. The amount sent to landfill could be reduced if the plastic bags: • could be reused • could be recycled by melting and making into new plastic products • could be burned to release energy Use the information above and your knowledge and understanding to give the positive and negative environmental impacts of using these methods to reduce the amount of plastic bags sent to landfill.
(6 marks) 3) The diagram shows the apparatus used to measure the energy released when a fuel is burned.
Describe how you would use this apparatus to compare the energy released when three different fuels are burned.
(4 marks) 4) Describe the process in which carbon is cycled through the air, plants, animals and microbes. You may use a flow diagram to help in your answer.
(5 marks) 5) Rock salt is a mixture containing salt (sodium chloride) that we get from the Earth’s crust. To get pure salt from rock salt we need to separate the pure salt from the other substances in the mixture. Describe how you would obtain pure salt from rock salt in the laboratory. You should include in your answer the apparatus that you would use.
(6 marks)
Q1. Atoms are made up of three main particles called protons, neutrons and electrons.
Use the periodic table on the data sheet to help you to answer these questions.
(a) Sodium is in Group 1 of the periodic table.
(i) Why are potassium and sodium in the same Group of the periodic table?
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(ii) How many protons are in an atom of sodium? ..................................... (1)
(iii) The atomic number of sodium is 11.
How many neutrons are in an atom of sodium with mass number 23?
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(iv) Each sodium atom has 11 electrons. Complete the electronic structure of sodium.
(2)
(b) The chemical equation for a reaction of sodium is shown below.
2Na + Cl2 → 2NaCl
Describe this reaction of sodium in terms of the names of the substances and the numbers of the atoms involved.
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(Total 8 marks)
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Q2. Limestone has been called the Earth’s most useful rock.
(a) Limestone contains calcium carbonate, CaCO3.
(i) Complete the table to show the number of atoms of each element in the formula of calcium carbonate.
Calcium has been done for you.
(2)
Element Number of atoms in the formula CaCO3
Calcium, Ca 1
Carbon, C
Oxygen, O
(ii) The diagram below represents a carbon atom.
Use words from the box to label the parts of this atom.
(2)
bond electron molecule nucleus
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(b) At a cement works, limestone is mixed with clay and heated in a kiln.
Use the information in the diagram to answer these questions.
(i) Name the fuel that is used to heat the limestone and clay.
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(ii) Limestone contains calcium carbonate, CaCO3.
Draw a ring around the correct gas in the box to complete the sentence.
(1)
The gas formed when calcium carbonate decomposes is
argon.
carbon dioxide.
nitrogen.
(c) The cement works starts to burn a different fuel.
Local residents are concerned because more children are suffering asthma attacks. Residents have also noticed that parked cars are becoming dirty because of smoke particles from the chimney.
The table shows the possible medical risk from smoke particles.
Particle size in mm Medical effect
Larger than 0.4 No medical risks known
0.3 and smaller Causes asthma attacks
0.2 and smaller May cause cancer
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(i) Give two reasons why local residents are concerned about the cement works burning a different fuel.
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2 ........................................................................................................................
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(ii) The company operating the cement works stated that smoke particles from the chimney had not changed since it started burning the different fuel.
If you were a local resident, what evidence would you like to see to help you decide if the company’s statement is true or not?
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(Total 10 marks)
Q3. A cement works changes the fuel it uses.
Local residents are concerned because more children are suffering asthma attacks.
Residents have also noticed that parked cars are becoming dirty because of smoke particles from the chimney.
The table shows the possible medical risk from smoke particles.
Particle size in mm Medical effect
Larger than 0.4 No medical risks known
0.3 and smaller Causes asthma attacks
0.2 and smaller May cause cancer
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It is also recommended that to avoid damage to health, the concentration of any particles should be no higher than 2 parts per million (ppm).
Scientists were brought in to monitor the emissions from the cement work’s chimney. They positioned four sensors around the cement works to monitor airborne smoke particles.
These four sensors only detect particle sizes larger than 0.5 mm and measure the concentration of particles in ppm. The scientists reported that the particle sensors showed that the average concentration of particles was 1.8 ppm. The scientists concluded that there was no risk to health.
(a) Suggest why the local residents objected to the positions of the four sensors.
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(b) What evidence did the scientists use to conclude that there was no risk to health?
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(c) The local residents were still concerned that there was a risk to health, even though the average concentration of particles was 1.8 ppm.
Suggest why they may still be concerned.
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(Total 6 marks)
Q4. Many everyday items are made from iron.
(a) Haematite is an ore of iron. Haematite contains iron oxide, Fe2O
3.
(i) What is the meaning of the term ore?
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(ii) Iron can be produced by reacting iron oxide with carbon in a blast furnace.
What type of reaction produces the iron?
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(iii) The word equation for this reaction is:
iron oxide + carbon → iron + carbon dioxide
Complete and balance the symbol equation for this reaction.
.....Fe2O
3 + .....C → ................... + ...................
(2)
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(b) Pure iron is relatively soft and not very strong.
The iron from the blast furnace is very hard and brittle. It contains about 4% carbon and is used as cast iron.
Explain the differences in the properties of pure iron and cast iron by referring to the diagrams.
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(c) The diagram shows the way in which iron is extracted, used and recycled.
Explain why the recycling of iron is necessary for sustainable development.
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(Total 10 marks)
Q5. Crude oil contains many useful substances.
(a) What is the name of the process used to separate the useful substances from crude oil?
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(b) Table 1 gives some information about some of the useful substances obtained from crude oil.
Table 1
Substance Number of
carbon atoms Boiling point (°C) Viscosity (cP)
Refinery gas 1–4 < 30 0.009
Petrol 4–10 50 0.5
Naptha 6–11 130 0.9
Kerosene 10–16 200 2.5
Diesel fuel 16–20 260 6.2
Lubricating oil 20–40 310 22.7
Describe the trends shown in the table.
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(c) The relative amounts of substances obtained from crude oil are given in Table 2.
Table 2
Substance Relative % in crude oil Relative % demand
Petrol 10 20
Kerosene 15 23
Diesel 20 25
Fuel oil 45 12
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Suggest why petrol costs more than fuel oil.
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(Total 7 marks)
Q6. Petrol is a hydrocarbon fuel.
(a) Complete this sentence.
Hydrocarbons are compounds which are made from the elements ...........................
and ........................................ only. (2)
(b) This apparatus was used to study the combustion of a hydrocarbon fuel.
(i) Name the substance which changed the anhydrous copper sulphate from white to blue.
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(ii) Carbon dioxide is also produced when the hydrocarbon fuel is burned. Name the solution, labelled X on the diagram, which tests for carbon dioxide.
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(iii) Complete this sentence.
Carbon dioxide turns solution X .............................................................................. (1)
(c) The graph shows how the concentration of carbon dioxide in the air has varied since the year 1000.
(i) Describe the changes in the concentration of carbon dioxide in the air since the year 1000.
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(ii) Suggest why the concentration of carbon dioxide in the air has changed since the year 1800.
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(Total 9 marks)
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Q7. The many hydrocarbons in crude oil are separated into fractions.
(a) Some of the larger hydrocarbon molecules can be broken down to produce smaller, more useful hydrocarbon molecules.
Hexane and butane are alkanes. Describe the structure of alkanes.
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(b) Ethene is used to make poly(ethene).
This process is called polymerisation. Explain what is meant by polymerisation.
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(Total 5 marks)
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Q8. Margarine is manufactured using ‘hard’ plant oils. A margarine company tested several plant oils to determine their hardness for use in its margarine.
In the test iodine solution was used to find the iodine value. The units are grams of iodine that react with 100 g of oil.
Plant oils with lower iodine values are harder and are less unsaturated.
Plant oil Melting point in °C Iodine value
Coconut 25 10
Palm 35 54
Olive –6 81
Castor –18 85
Peanut 3 93
Rapeseed –10 98
Sunflower –17 125
Soya bean –16 130
(a) Do the results in the table indicate that there is a relationship between the melting point of a plant oil and its hardness?
Explain your answer.
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(b) The company stated that some of the plant oils were brown and that this may have affected the results.
Explain why the company considered the colour of plant oils to be a problem with this test.
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(c) A consumer group stated that the test should not be carried out by the margarine company but by independent scientists.
Explain why.
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(d) The company intends to use sunflower oil to make its margarine.
Explain how the company could process the sunflower oil to make it suitable for the manufacture of margarine.
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(Total 9 marks)
Q9. The label on a bottle of salad dressing shows that the dressing contains the following ingredients.
(a) One of the main ingredients in salad dressing is vegetable oil.
Ingredients
Water Vegetable oil Egg yolk Sugar Flour Vinegar Salt
Extract of spices Preservative E202 Emulsifier E405
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(i) Use the correct word from the box to complete the sentence about the extraction of vegetable oil.
To extract the vegetable oil, the fruits or seeds of plants are first
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crushed evaporated hardened
(ii) The liquids can be separated from the solid parts of the fruits or seeds by filtering.
Suggest one reason why separation by filtering is better than separation by distilling.
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(b) (i) A mixture of vegetable oil and water is shaken and left to stand for several minutes. The diagram shows the result.
Complete the following sentence.
The vegetable oil and water .................................................................................... . (1)
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(ii) A mixture of vegetable oil, water and egg yolk is shaken and left to stand for several minutes.
The diagram shows the result.
Use words from the box to complete the sentence.
The egg yolk causes vegetable oil and water to ........................................................
and form an ..................................................... . (2)
(Total 5 marks)
additive distil emulsion extract mix separate
Q10. Scientists study the atmosphere on planets and moons in the Solar System to understand how the Earth’s atmosphere has changed.
(a) Millions of years ago the Earth’s atmosphere was probably just like that of Mars today.
The table shows data about the atmospheres of Mars and Earth as they are now.
Suggest what has caused the main gases in the Earth’s atmosphere of millions of years ago to change to the present-day atmosphere.
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Mars Earth
nitrogen 3% nitrogen 78%
oxygen trace oxygen 21%
water trace water trace
carbon dioxide 95% carbon dioxide trace
Average surface temperature –23 °C Average surface temperature 15 °C
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(b) Titan is the largest moon of the planet Saturn. It has an atmosphere that, like the Earth’s, contains mainly nitrogen. Methane is the other main gas.
When it rains on Titan, it rains methane! Explain why.
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Main gases in Titan’s atmosphere
Percentage (%) Boiling point in °C
Nitrogen 95 –196
Methane 5 –164
Average surface temperature –178 °C
(c) Ultraviolet radiation from the Sun produces simple alkenes, such as ethene and propene, from methane in Titan’s atmosphere.
(i) Draw the structure of propene, C3H
6, to show the covalent bonds.
(1)
(ii) Explain how propene molecules form a polymer. You should name the polymer formed.
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(Total 8 marks)
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Q11. (a) During the first billion years of the Earth’s existence, there were many active volcanoes. The volcanoes released the gases that formed the early atmosphere.
Describe how volcanoes caused the oceans to be formed.
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(b) The atmosphere on Earth today is very different from the early atmosphere.
The pie chart shows the amounts of different gases in the air today. Choose gases from the box to label the pie chart.
(2)
(Total 4 marks)
argon carbon dioxide hydrogen nitrogen oxygen
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Q12. (a) The diagram shows the layered structure of the Earth.
(i) Write in the boxes the name of layer X and the name of layer Y. (2)
(ii) The overall density of the Earth is about 5500 kg/m3. The average density of the rocks in the Earth’s crust is about 2800 kg/m3. What does this suggest about the material that makes up the lower layers of the Earth?
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(b) In 1915, the scientist Alfred Wegener suggested that Africa and South America had once been joined but had since drifted apart. Evidence for his theory came from the animal fossils found in the two continents. The fossils are almost the same, although animals now living in Africa and South America are different. Other scientists did not agree with Wegener and suggested that a land bridge had once joined the two continents.
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How could scientists use the idea of a land bridge to explain the evidence put forward by Wegener?
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(c) Scientists now think that the outer layer of the Earth is cracked into a number of large pieces called tectonic plates. The tectonic plates are moving very slowly. The lines on the diagram show the boundaries between the major tectonic plates.
(i) Explain why there are no major earthquakes in Britain.
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(ii) What is causing the tectonic plates to move?
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(Total 9 marks)
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