Chemistry of the environment: past paper questions

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• Question 28May/June 2026, paper 11Multiple choice1 markHas a diagram

  A solution of sodium chloride in water is tested with anhydrous copper(II) sulfate and anhydrous cobalt(II) chloride. The boiling point of the solution at 1 atm pressure is also measured. Which row is correct?

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• Question 28Oct/Nov 2025, paper 11Multiple choice1 mark

  Which substance is used to remove odours in the treatment of the domestic water supply?

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• Question 22Oct/Nov 2024, paper 11Multiple choice1 markHas a diagram

  When heated, copper(II) sulfate crystals, ${\text{CuSO}}_4\cdot 5{\text{H}}_2\text{O}$, react as shown. $${\text{CuSO}}_4\cdot 5{\text{H}}_2\text{O}(\text{s})\to {\text{CuSO}}_4(\text{s})+5{\text{H}}_2\text{O}(\text{g})$$ When ......1...... copper(II) sulfate, which is ......2......

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• Question 30Oct/Nov 2023, paper 11Multiple choice1 mark

  Which statement about natural sources of water and the domestic water supply is correct?

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• Question 29May/June 2026, paper 11Multiple choice1 mark

  NPK fertilisers are used to provide three elements for improved plant growth. Which mixture of compounds contains all three of these elements?

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• Question 29Oct/Nov 2025, paper 11Multiple choice1 mark

  Carbon dioxide, methane and oxygen are gases involved in the carbon cycle. Which of these gases cause global warming?

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• Question 28Oct/Nov 2024, paper 11Multiple choice1 markHas a diagram

  The domestic water supply is treated to make it safe to drink. Which row identifies the treatment and its effect?

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• Question 31Oct/Nov 2023, paper 11Multiple choice1 mark

  Gases that may be present in the air are listed. 1 neon 2 carbon monoxide 3 nitrogen 4 methane Which gases are atmospheric pollutants?

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• Question 30May/June 2026, paper 11Multiple choice1 markHas a diagram

  Which row about carbon dioxide and methane is correct?

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• Question 28Oct/Nov 2025, paper 12Multiple choice1 mark

  Water may contain many substances before it is purified for drinking. Three substances are listed. 1 dissolved oxygen 2 harmful microbes 3 insoluble solids Which substances are removed by the treatment of the domestic water supply?

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• Question 29Oct/Nov 2024, paper 11Multiple choice1 markHas a diagram

  Sodium phosphate, ${\text{Na}}_3{\text{PO}}_4$, and ammonium nitrate, ${\text{NH}}_4{\text{NO}}_3$, are both used as fertilisers. Which row shows the correct percentage by mass of the element in each compound that improves plant growth?

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• Question 30Oct/Nov 2023, paper 12Multiple choice1 mark

  Which statement about water is correct?

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• Question 29May/June 2026, paper 12Multiple choice1 mark

  Water is added to anhydrous cobalt(II) chloride. Which colour change is seen?

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• Question 29Oct/Nov 2025, paper 12Multiple choice1 mark

  Dry air is a mixture of gases. 99% of the mixture is nitrogen and oxygen. What is in the highest abundance in the remaining 1%?

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• Question 30Oct/Nov 2024, paper 11Multiple choice1 markHas a diagram

  Three processes are shown. 1 the decomposition of vegetation 2 emissions from a car engine 3 photosynthesis Which row shows a gas produced in each process?

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• Question 31Oct/Nov 2023, paper 12Multiple choice1 markHas a diagram

  Some compounds that can be used as fertilisers are listed.

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• Question 30May/June 2026, paper 12Multiple choice1 mark

  Z is a pollutant gas that is formed in car engines. An aqueous solution of Z is acidic. Z is removed from the exhaust gases in a catalytic converter by reduction.

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• Question 10Oct/Nov 2025, paper 21Structured5 marks

  Air is a mixture of gases. State the percentage by volume of oxygen in clean, dry air.

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• Question 11Oct/Nov 2024, paper 12Multiple choice1 mark

  Which fertiliser contains the highest percentage by mass of nitrogen?

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• Question 32Oct/Nov 2023, paper 12Multiple choice1 markHas a diagram

  Different strategies to reduce the effects of environmental issues have been suggested. Which row is correct?

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• Question 10Oct/Nov 2025, paper 22Structured7 marks

  Water is an important part of the environment. Rivers and lakes are natural sources of water. Name one substance in river water that may be harmful.

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• Question 32Oct/Nov 2024, paper 12Multiple choice1 markHas a diagram

  Which row describes an advantage and a disadvantage of fertilisers?

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• Question 1Oct/Nov 2023, paper 21Structured5 marks

  Choose from the list of compounds to answer these questions. calcium oxide carbon dioxide carbon monoxide lead chloride propan-1-ol sodium nitrate sodium sulfate sulfur dioxide water Each compound may be used once, more than once or not at all.

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• Question 29May/June 2025, paper 11Multiple choice1 markHas a diagram

  Chlorine and carbon are both used in the treatment of the domestic water supply. Which row describes one reason for the use of each substance?

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• Question 33Oct/Nov 2024, paper 12Multiple choice1 markHas a diagram

  Which row about the adverse effects of air pollutants is correct?

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• Question 6Oct/Nov 2023, paper 21Structured7 marks

  The equation for the Haber process used in the production of ammonia is shown. $${\mathrm{N}}_2+3{\mathrm{H}}_2\rightleftharpoons 2{\mathrm{N}\mathrm{H}}_3$$ The nitrogen for this process comes from the air. State the percentage by volume of nitrogen in clean, dry air.

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• Question 30May/June 2025, paper 11Multiple choice1 markHas a diagram

  Which row states an adverse effect for the named pollutant?

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• Question 39Oct/Nov 2024, paper 12Multiple choice1 markHas a diagram

  Three liquids, X, Y and Z, are tested and the results are shown.

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• Question 7Oct/Nov 2023, paper 21Structured11 marks

  Dilute ethanoic acid reacts with aqueous calcium hydroxide.

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• Question 31May/June 2025, paper 11Multiple choice1 mark

  Three statements about global warming and greenhouse gases are listed. 1 Global warming is occurring because more of the Earth's thermal energy is released to space. 2 Greenhouse gases both absorb and emit thermal energy.

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