Chemistry · Oct / Nov 2023 · Paper 11 · Question 30

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

1. AChlorine is used to remove tastes and odours in the treatment of the domestic water supply.
2. BMetal compounds from detergents can deoxygenate natural sources of water.
3. CPhotosynthesis provides the oxygen needed for aquatic life in natural sources of water.
4. DSedimentation removes nitrates in the treatment of the domestic water supply.

As printed in the paper