Chemistry 5070 · O Level · Redox

Redox — practice question

X is a colourless solution. A few drops of aqueous potassium iodide solution are introduced into a sample of X. There is no visible change. Y is also a colourless solution. A few drops of aqueous acidified potassium manganate(VII) solution are added to a sample of Y. The purple colour of the potassium manganate(VII) vanishes. What can be inferred about X and Y from these two observations?

  • AX and Y are both reducing agents.
  • BX is an oxidising agent and Y is not a reducing agent.
  • CX is not a reducing agent and Y is an oxidising agent.
  • DX is not an oxidising agent and Y is a reducing agent.

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