Chemistry · May / June 2021 · Paper 12 · Question 20

Solution X is colourless. A few drops of aqueous potassium iodide solution are added to a sample of X. No change is seen. Solution Y is colourless. A few drops of aqueous acidified potassium manganate(VII) solution are added to a sample of Y. The colour of the potassium manganate(VII) disappears. What can be deduced about X and Y from these two observations?

1. AX and Y are both reducing agents.
2. BX is an oxidising agent and Y is not a reducing agent.
3. CX is not a reducing agent and Y is an oxidising agent.
4. DX is not an oxidising agent and Y is a reducing agent.

As printed in the paper