O-LevelChemistryChemistry of the Environment5070/11 · May/June 2025 · Q291 Mark

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?

Acauses the sedimentation of some solids | removes tastes from the water

Bcauses the sedimentation of some solids | removes dissolved oxygen from the water

Ckills some microbes | removes tastes from the water

Dkills some microbes | removes dissolved oxygen from the water

✓ Correct answer

C: kills some microbes | removes tastes from the water

Oracle Prep sorts past-paper questions by topic, so you can drill Chemistry of the Environment and see which topics are most likely to come up next.

Topic: Chemistry of the Environment, O-Level Chemistry (syllabus 5070). Multiple choice, 1 mark.
Source: O-Level Chemistry, May/June 2025 Paper 1 Variant 1, question 29.

Questions and mark schemes are from past examination papers and remain the copyright of the exam board. How Oracle Prep builds its content