Water: past paper questions

Where the questions come from

• 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 12Multiple choice1 mark

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

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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 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 30Oct/Nov 2023, paper 12Multiple choice1 mark

  Which statement about water 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 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 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 24May/June 2024, paper 11Multiple choice1 mark

  The water in a lake is acidic and the fish are dying. The water in the lake needs to be neutralised so that its pH is close to 7. Which compound is added in excess to neutralise the water in the lake?

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• Question 1Oct/Nov 2023, paper 22Structured5 marks

  Choose from the list of compounds to answer these questions. ammonia ethanol glucose magnesium chloride magnesium oxide methane nitrogen dioxide phosphorus(V) chloride poly(ethene) sodium bromide water Each compound may be used once, more than once or not at all.

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• Question 29May/June 2025, paper 12Multiple choice1 markHas a diagram

  The domestic water supply is treated before it is supplied to houses. Three treatments are listed. ● sedimentation and filtration ● treatment with chlorine ● treatment with carbon Which row shows the purpose of the treatments?

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• Question 24May/June 2024, paper 12Multiple choice1 mark

  Which statement about water of crystallisation is correct?

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• Question 30May/June 2023, paper 11Multiple choice1 mark

  What is a cause of deoxygenation of water in a lake?

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• Question 30May/June 2024, paper 12Multiple choice1 mark

  The presence of water can be confirmed by the use of either anhydrous cobalt(II) chloride or anhydrous copper(II) sulfate. Which observation is correct if water is present?

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• Question 31May/June 2023, paper 11Multiple choice1 mark

  Dissolved substances can cause eutrophication and the deoxygenation of water. How many of the ions shown cause this effect?

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• Question 1May/June 2024, paper 21Structured5 marks

  Choose from the following substances to answer the questions. carbon chlorine glucose hydrated copper(II) sulfate iron magnesium sulfate methanoic acid methanol nickel silicon(IV) oxide vanadium(V) oxide Each substance can be used once, more than once or not at all.

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• Question 32May/June 2023, paper 12Multiple choice1 mark

  Why is carbon used in water purification?

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• Question 1May/June 2024, paper 22Structured5 marks

  Choose from the following substances to answer the questions.

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• Question 1May/June 2023, paper 21Structured6 marks

  Choose from the following oxides to answer the questions.

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