Water: past paper questions
Real questions on water
The newest 20 of 93 written questions. Open one to see it on the real paper.
- 0620/31 · May/June 2026 · Q1a(vi)[1]
is used in photosynthesis.
See it on the paper → - 0620/31 · May/June 2026 · Q7a[1]
State the percentage of clean, dry air that is nitrogen.
See it on the paper → - 0620/31 · May/June 2026 · Q7c[2]
Water from natural sources can be polluted with harmful substances. State why sewage and phosphates in river water are harmful. sewage phosphates
See it on the paper → - 0620/32 · May/June 2026 · Q7a(ii)[1]
State one reason why nitrates in river water are harmful.
See it on the paper → - 0620/32 · May/June 2026 · Q7d[3]
Figure 7.1 shows three stages in the treatment of the domestic water supply. impure water sedimentation and filtration addition of carbon chlorination drinking water Figure 7.1 State what happens at each stage in the treatment of the domestic water supply. sedimentation and filtration addition of carbon chlorination
See it on the paper → - 0620/33 · May/June 2026 · Q7a[2]
Natural water sources can be polluted with sewage and nitrates. State why sewage and nitrates in river water are harmful. sewage nitrates
See it on the paper → - 0620/33 · May/June 2026 · Q7d(i)[1]
Describe how solids are removed from the domestic water supply.
See it on the paper → - 0620/33 · May/June 2026 · Q7d(ii)[1]
Name the substance added to the domestic water supply to remove tastes and odours.
See it on the paper → - 0620/42 · May/June 2026 · Q3d(i)[1]
State the term used to describe a solution containing the maximum concentration of solute.
See it on the paper → - 0620/43 · May/June 2026 · Q1d[1]
photosynthesis
See it on the paper → - 0620/43 · May/June 2026 · Q2a(iv)[1]
removes tastes and odours from the domestic water supply
See it on the paper → - 0620/31 · October/November 2025 · Q5b[1]
State the use of chlorine in the treatment of the domestic water supply.
See it on the paper → - 0620/32 · October/November 2025 · Q3b[1]
The water sample is not suitable for use in practical chemistry. Name a process that makes the water suitable for use in practical chemistry.
See it on the paper → - 0620/32 · October/November 2025 · Q3c(i)[1]
State why carbon is used in the treatment of water.
See it on the paper → - 0620/32 · October/November 2025 · Q3c(ii)[1]
State why water is chlorinated.
See it on the paper → - 0620/63 · October/November 2025 · Q1b[1]
When the fuel is burned, the steam produced passes into the U-tube. Suggest why the U-tube is surrounded by ice.
See it on the paper → - 0620/63 · October/November 2025 · Q1c[1]
Water causes solid X in the U-tube to change colour. Name solid X and state the colour change seen. solid X The student tries to use the apparatus in Fig. 1.2 to pass the gases produced through acidified aqueous potassium manganate( VII ). There is an error in the apparatus in Fig. 1.2 so that the gases produced will n...
See it on the paper → - 0620/31 · May/June 2025 · Q8a[1]
River water needs to be treated to make it safe to drink. Two of the stages used in the treatment of domestic water are the addition of carbon and chlorination. Describe the reason for each of these stages. chlorination addition of carbon
See it on the paper → - 0620/31 · May/June 2025 · Q8b[1]
Describe how to test whether a sample of water is pure using boiling point.
See it on the paper → - 0620/31 · May/June 2025 · Q8c[1]
Explain why distilled water is used in practical chemistry rather than tap water.
See it on the paper →
What examiners said
Few candidates recalled reasons for using carbon in water treatment. Many gave vague answers such as ‘to make it pure’. Many were able to describe the use of chlorine in the killing of microorganisms/bacteria. Candidates should note that chlorine does not ‘remove’ bacteria from the water.
— Examiner report, May/June 2025, 0620/31 Q8(a) (Cambridge)
This question required candidates to describe the action of heating and then to measure the boiling point of water. They should then compare the value to the expected value of 100 C. Many assumed this question was linked to the previous question and suggested heating the water to dryness and checking for residue, which did not answer the question asked. Other common errors included timing how long...
— Examiner report, May/June 2025, 0620/31 Q8(b) (Cambridge)
A majority of candidates recognised that distilled water is either pure or purer than tap water.
— Examiner report, May/June 2025, 0620/31 Q8(c) (Cambridge)
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