Interpreting and interacting with earth systems: OCR GCSE Chemistry A questions

Every OCR GCSE Chemistry A exam question on C6.3 Interpreting and interacting with earth systems, 2018–2025, with its mark scheme and examiner’s report.

All 70 questions on Interpreting and interacting with earth systems, as a list

June 2025, Paper 2 Foundation, Q14 (1 mark): Which row in the table shows the change in the percentage of each gas in the Earth’s atmosphere today compared to the Earth’s early atmosphere? Carbon dioxide O
June 2025, Paper 2 Foundation, Q19(a) (1 mark): Why may the increase in the world population have caused the increase in the concentration of carbon dioxide in the atmosphere? Tick (✓) one box. More fossil fu
June 2025, Paper 2 Foundation, Q19(b) (2 marks): A problem with an increase in the concentration of carbon dioxide is global warming. State two problems caused by global warming. 1 2 [2]
June 2025, Paper 4 Higher, Q1 (1 mark): Which row in the table shows the change in the percentage of each gas in the Earth’s atmosphere today compared to the Earth’s early atmosphere? Carbon dioxide O
June 2025, Paper 4 Higher, Q23(a) (2 marks): Why may the increase in the world population have caused the increase in the concentration of carbon dioxide in the atmosphere? [2]
June 2025, Paper 4 Higher, Q23(b) (1 mark): State one possible problem associated with an increase in the concentration of carbon dioxide in the atmosphere. [1]
June 2024, Paper 2 Foundation, Q4 (1 mark): What is the major source of oxides of nitrogen in the atmosphere? A Combustion of impurities in coal B High temperature reactions in car engines C Incomplete co
June 2024, Paper 2 Foundation, Q12 (1 mark): 4.8 dm3 of air contains 0.12 dm3 of water vapour. What is the percentage of water vapour in the air? A 0.3% B 2.5% C 12.0% D 97.5% Your answer [1]
June 2024, Paper 2 Foundation, Q16(c) (1 mark): Carbon monoxide, CO, is made in the incomplete combustion of methane. State why carbon monoxide is a problem. [1]
June 2024, Paper 2 Foundation, Q18(a) (3 marks): The sentences describe one possible theory for how the Earth’s atmosphere evolved. A The Earth cooled. B Carbon cycle now keeps the composition of the atmospher
June 2024, Paper 2 Foundation, Q18(b) (2 marks): Complete the table to show the gases in the Earth’s atmosphere today. Percentage in Earth’s Gas atmosphere (%) 78 21 Carbon dioxide / noble gases / water vapour
June 2024, Paper 2 Foundation, Q18(c)(i) (1 mark): State the name used for water that is safe to drink. [1]
June 2024, Paper 2 Foundation, Q18(c)(ii) (1 mark): Explain why chlorine is added to water to make it safe to drink. [1]
June 2024, Paper 2 Foundation, Q18(d)(i) (3 marks): There is a link between the amount of sulfur dioxide in the atmosphere and the amount of acid rain. Complete the table by correctly identifying which word finis
June 2024, Paper 2 Foundation, Q18(d)(ii) (1 mark): State one problem caused by acid rain. [1]
June 2024, Paper 4 Higher, Q6 (1 mark): Nitrogen and oxygen react together at high temperatures in car engines. Nitrogen monoxide is made. What is the balanced equation for the reaction? A N + O NO B
June 2024, Paper 4 Higher, Q20(a) (3 marks): Describe how the amounts of these gases changed over time to develop an oxygen-rich atmosphere. [3]
June 2024, Paper 4 Higher, Q20(b)(i) (1 mark): Describe the relationship between the percentage of carbon dioxide and the percentage of nitrogen in the atmosphere. [1]
June 2024, Paper 4 Higher, Q20(b)(ii) (1 mark): Estimate when the percentage of carbon dioxide and the percentage of oxygen were equal. Answer = millions of years ago [1]
June 2024, Paper 4 Higher, Q20(c)(i) (3 marks): Describe the link between the amount of sulfur dioxide in the atmosphere and the concentration of the hydrogen ion, H+, in the rainwater between the years 2000
June 2024, Paper 4 Higher, Q20(c)(ii) (1 mark): Since 2014 the amount of acid rain in the atmosphere has decreased. Suggest why. [1]
June 2023, Paper 2 Foundation, Q6 (1 mark): Tap water is treated to make it safe to drink. Which substance is added to the tap water to kill bacteria and microbes? A Aluminium sulfate B Carbon dioxide C C
June 2023, Paper 2 Foundation, Q9 (1 mark): What was the main gas in the Earth’s early atmosphere? A Ammonia B Carbon dioxide C Nitrogen D Oxygen Your answer [1]
June 2023, Paper 2 Foundation, Q18(d)(i) (1 mark): State an environmental problem caused by increased levels of carbon dioxide gas. [1]
June 2023, Paper 2 Foundation, Q18(d)(ii) (1 mark): Explain how this environmental problem can be reduced. [1]
June 2023, Paper 4 Higher, Q4 (1 mark): Which gas was the most abundant in the Earth’s early atmosphere? A Argon B Carbon dioxide C Nitrogen D Oxygen Your answer [1]
June 2023, Paper 4 Higher, Q6 (1 mark): Which row in the table shows three greenhouse gases? A argon carbon dioxide nitrogen B carbon dioxide methane water vapour C hydrogen methane water vapour D car
June 2023, Paper 4 Higher, Q11 (1 mark): Which statement about the greenhouse effect is correct? A Greenhouse gases absorb all the infrared radiation that is emitted by the Earth’s surface. B Greenhous
June 2022, Paper 2 Foundation, Q18(c) (2 marks): Describe two potential problems of increased levels of carbon dioxide in the Earth’s atmosphere. 1 2 [2]
June 2022, Paper 2 Foundation, Q18(d) (1 mark): The electricity used to charge the electric car can be produced by burning coal which produces a large amount of carbon dioxide. The amount of carbon dioxide pr
June 2022, Paper 2 Foundation, Q20(a) (2 marks): Explain why carbon monoxide in the atmosphere is a problem. [2]
June 2022, Paper 2 Foundation, Q20(b) (1 mark): Sulfur dioxide causes acid rain. Why is acid rain a problem? [1]
June 2022, Paper 2 Foundation, Q20(c)(i) (1 mark): Calculate the percentage emissions of oxides of nitrogen from cars. Percentage emissions of oxides of nitrogen from cars = % [1]
June 2022, Paper 2 Foundation, Q20(c)(ii) (1 mark): What is the largest source of emissions of oxides of nitrogen? [1]
June 2022, Paper 4 Higher, Q8 (1 mark): Which gases is the Earth’s early atmosphere thought to have contained? A Carbon dioxide and oxygen B Carbon dioxide and water vapour C Methane and oxygen D Nitr
June 2022, Paper 4 Higher, Q18(f) (2 marks): Petrol is a mixture of hydrocarbons obtained from crude oil. When petrol burns in a car engine the exhaust gases contain nitrogen monoxide, NO, and carbon monox
June 2022, Paper 4 Higher, Q23(b)(ii) (2 marks): The CO2 emissions for an electric car are much greater when the car is refuelled using electricity generated by burning coal, rather than renewable electricity.
November 2021, Paper 2 Foundation, Q1 (1 mark): The burning of fossil fuels can produce gases that cause acid rain. Which gas causes acid rain? A Carbon monoxide B Nitrogen C Oxygen D Sulfur dioxide Your answ
November 2021, Paper 2 Foundation, Q6 (1 mark): The Earth’s early atmosphere was mostly carbon dioxide gas. The Earth’s atmosphere now contains only about 0.04% carbon dioxide gas. Which process decreased the
November 2021, Paper 2 Foundation, Q17(f) (2 marks): Incomplete combustion of nonane makes carbon monoxide instead of carbon dioxide. Describe and explain one problem caused by carbon monoxide. [2]
November 2021, Paper 4 Higher, Q3 (1 mark): The Earth’s early atmosphere formed 4.5 billion years ago. Which process produced the gases in the Earth’s early atmosphere? A Combustion B Condensation C Photo
November 2020, Paper 2 Foundation, Q21(a) (1 mark): Explain why the amount of carbon dioxide in the atmosphere today has decreased from the early atmosphere. [1]
November 2020, Paper 2 Foundation, Q21(b) (1 mark): The graph shows the amount of carbon dioxide in the Earth’s atmosphere from 1970 to 2010. 400 380 Amount of carbon dioxide 360 (parts per million) 340 320 1970
November 2020, Paper 2 Foundation, Q21(c)(i) (1 mark): Write down one way that carbon dioxide is released into the atmosphere. [1]
November 2020, Paper 2 Foundation, Q21(c)(ii) (1 mark): Write down one way to reduce the amount of carbon dioxide that is released into the atmosphere. [1]
November 2020, Paper 2 Foundation, Q21(d)(i) (1 mark): Suggest a value for the pH of sulfur dioxide. [1]
November 2020, Paper 2 Foundation, Q21(d)(ii) (1 mark): Describe one problem caused by sulfur dioxide. [1]
November 2020, Paper 4 Higher, Q23(a) (2 marks): Evaluate the information shown in the graph. To what extent does the graph support a link between carbon dioxide levels and global warming? [2]
November 2020, Paper 4 Higher, Q23(b) (3 marks): Describe and explain what is meant by the greenhouse effect. [3]
November 2020, Paper 4 Higher, Q23(c)(i) (1 mark): State a human activity that can cause an enhanced greenhouse effect. [1]
November 2020, Paper 4 Higher, Q23(c)(ii) (2 marks): State two environmental effects of an enhanced greenhouse effect. 1 2 [2]
June 2019, Paper 2 Foundation, Q1 (1 mark): Which type of water is potable water? A Groundwater B Seawater C Tap water D Waste water Your answer [1]
June 2019, Paper 2 Foundation, Q5 (1 mark): How was the Earth’s early atmosphere formed? A Animals breathing B Global warming C Plants growing D Volcanic activity [1] Your answer
June 2019, Paper 2 Foundation, Q15 (1 mark): The table shows the composition of the Earth’s early atmosphere compared with the atmosphere today. Carbon Nitrogen Oxygen Argon dioxide Percentage of gas in th
June 2019, Paper 2 Foundation, Q23(a) (3 marks): Evaluate the information shown in the graph. To what extent does the graph support a link between human activity and global warming? [3]
June 2019, Paper 2 Foundation, Q23(b) (2 marks): There are problems with using information about CO2 emissions by fossil fuels to draw conclusions about the effect of carbon dioxide emissions on global sea lev
June 2019, Paper 2 Foundation, Q23(c)(i) (1 mark): Describe one effect on the Earth’s climate of increased carbon dioxide levels, other than rising sea levels. [1]
June 2019, Paper 2 Foundation, Q23(c)(ii) (1 mark): Suggest how we can lower carbon dioxide levels. [1]
June 2019, Paper 4 Higher, Q2 (1 mark): The table shows the composition of the Earth’s early atmosphere compared with the atmosphere today. Carbon Nitrogen Oxygen Argon dioxide Percentage of gas in th
June 2019, Paper 4 Higher, Q3 (1 mark): Which of these pairs of gases are both greenhouse gases? A Nitrogen and methane B Nitrogen and oxygen C Water vapour and methane D Water vapour and oxygen Your
June 2019, Paper 4 Higher, Q12 (1 mark): Which statement about the greenhouse effect and greenhouse gases is correct? A Greenhouse gases absorb all the infrared radiation that is emitted by the Earth’s
June 2019, Paper 4 Higher, Q17(a) (3 marks): Evaluate the information shown in the graph. To what extent does the graph support a link between human activity and global warming? [3]
June 2019, Paper 4 Higher, Q17(b) (2 marks): There are problems with using information about CO2 emissions by fossil fuels to draw conclusions about the effect of carbon dioxide emissions on global sea lev
June 2019, Paper 4 Higher, Q17(c)(i) (1 mark): Describe one effect on the Earth’s climate of increased carbon dioxide levels, other than rising sea levels. [1]
June 2019, Paper 4 Higher, Q17(c)(ii) (1 mark): Suggest how we can lower carbon dioxide levels. [1]
June 2018, Paper 2 Foundation, Q13 (1 mark): What is the major source of carbon monoxide in the Earth’s atmosphere? A Incomplete combustion of fossil fuels and wood. B Production in a nuclear power station
June 2018, Paper 2 Foundation, Q14 (1 mark): Look at the following sentences. They describe one possible theory for how the Earth’s atmosphere evolved. The sentences are not in the correct order. Carbon cy
June 2018, Paper 2 Foundation, Q22(a) (2 marks): Complete the following paragraph about the greenhouse effect. Use words from the list. CFCs cool Earth’s hydrogen infrared methane microwave Sun’s ultraviolet w
June 2018, Paper 2 Foundation, Q22(b) (2 marks): Write about two possible ways that greenhouse gas emissions can be reduced. [2]
June 2018, Paper 4 Higher, Q5 (1 mark): The following statements describe one possible theory for how the Earth’s atmosphere evolved. The statements are not in the correct order. 1 Formation of water

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