AQA GCSE Chemistry — Paper 2 (Foundation Tier)

Total marks: 100 · Duration: 105 minutes · Tier: Foundation

Instructions to candidates

• Answer all questions in the spaces provided.
• You are expected to use a calculator where appropriate.
• This paper covers Topics 6–10: The Rate and Extent of Chemical Change, Organic Chemistry, Chemical Analysis, Chemistry of the Atmosphere, and Using Resources.
• A periodic table is provided.
• The maximum mark for this paper is 100. The marks for each question are shown in brackets.

Paper

Section A — Multiple Choice (10 marks)

For each question, choose the one correct answer.

1. Increasing the temperature of a reaction usually makes the rate… (1 mark) A) slower B) faster C) stay the same D) stop

2. A catalyst works by… (1 mark) A) increasing the activation energy B) being used up C) providing a different pathway with lower activation energy D) cooling the reaction

3. The general formula of the alkanes is… (1 mark) A) CₙH₂ₙ B) CₙH₂ₙ₊₂ C) CₙHₙ D) CₙH₂ₙ₋₂

4. Which is used to test for chlorine gas? (1 mark) A) A glowing splint B) Damp blue litmus paper (bleaches) C) Limewater D) A lighted splint

5. Roughly what percentage of the atmosphere is oxygen? (1 mark) A) 78% B) 21% C) 1% D) 0.04%

6. Carbon monoxide is dangerous because it… (1 mark) A) is flammable only B) reduces the blood's ability to carry oxygen C) causes acid rain D) is an alkali

7. Which gas is the main cause of recent global warming? (1 mark) A) Nitrogen B) Oxygen C) Carbon dioxide D) Argon

8. Potable water is water that is… (1 mark) A) pure B) safe to drink C) distilled D) from the sea

9. Which process separates a soluble salt from its solution? (1 mark) A) Filtration B) Crystallisation C) Chromatography D) Decanting

10. Recycling a metal rather than extracting it from ore mainly saves… (1 mark) A) water only B) energy and finite resources C) oxygen D) nothing

Section B — Structured Questions (90 marks)

11. A student investigated the rate of reaction between magnesium and dilute hydrochloric acid. (13 marks) (a) Name the gas produced. (1 mark) (b) Describe two methods to follow the rate of this reaction. (2 marks) (c) Explain, using collision theory, why increasing the concentration of the acid increases the rate. (3 marks) (d) Explain why smaller pieces of magnesium react faster. (2 marks) (e) Sketch and describe how the rate changes over time as the reaction proceeds, and explain why it eventually stops. (3 marks) (f) State the effect of a catalyst on the activation energy. (2 marks)

12. Crude oil is a source of fuels and feedstock. (12 marks) (a) What is a hydrocarbon? (2 marks) (b) Name the process used to separate crude oil into fractions. (1 mark) (c) Explain why this process works. (2 marks) (d) Explain why long-chain hydrocarbons are cracked. (2 marks) (e) Describe the test for an alkene and the result. (2 marks) (f) Write the products of the complete combustion of a hydrocarbon. (3 marks)

13. Polymers are large molecules. (10 marks) (a) Name the type of small molecule that joins together to make a polymer. (1 mark) (b) Give one use of poly(ethene). (1 mark) (c) Explain one environmental problem caused by disposing of polymers. (2 marks) (d) Give two advantages of recycling plastics. (2 marks) (e) Describe the difference between addition and condensation polymerisation in simple terms. (2 marks) (f) Suggest why a plant-based (biodegradable) polymer may be better for the environment. (2 marks)

14. Chemical analysis identifies substances. (13 marks) (a) Describe the flame-test colours for: sodium, potassium, copper. (3 marks) (b) Describe the test and result for hydrogen gas. (2 marks) (c) A student carried out paper chromatography on a food colouring. Explain how to calculate the Rf value. (2 marks) (d) Explain why one dye travels further than another. (2 marks) (e) Give two advantages of instrumental analysis over chemical tests. (2 marks) (f) Describe the test and result for carbon dioxide. (2 marks)

15. The atmosphere has changed over time. (12 marks) (a) Name the gas that made up most of the early atmosphere. (1 mark) (b) Explain how oxygen levels rose over billions of years. (2 marks) (c) Name two greenhouse gases. (2 marks) (d) Describe how greenhouse gases cause global warming. (3 marks) (e) Give two possible effects of global warming. (2 marks) (f) Suggest two actions that reduce a person's carbon footprint. (2 marks)

16. The Earth provides resources for life. (15 marks) (a) Explain the difference between a finite and a renewable resource, with an example of each. (4 marks) (b) Describe how drinking water is produced from fresh water in the UK. (3 marks) (c) Explain why sea water must be desalinated to be made potable, and why this is expensive. (2 marks) (d) Extended response: Compare the environmental advantages and disadvantages of recycling metals with extracting them from their ores. (6 marks)

17. This question is about rates, analysis and the environment. (15 marks) (a) What is a catalyst? (2 marks) (b) Use collision theory to explain why increasing the temperature increases the rate of reaction. (3 marks) (c) Describe the test, and result, for oxygen gas. (2 marks) (d) In paper chromatography, state how the Rf value is calculated. (2 marks) (e) Name two greenhouse gases. (2 marks) (f) Explain one environmental problem caused by burning fossil fuels. (2 marks) (g) Give two ways the use of finite resources can be reduced. (2 marks)