Question

A dilute ferrous sulphate solution is gradually added to the beaker containing acidified permanganate solution. The light purple colour of the solution fades and finally disappears. Which of the following is the correct explanation for the observation?

पर्याय

• KMnO₄ is an oxidising agent and it oxidises FeSO₄

• FeSO₄ acts as an oxidising agent and it oxidises KMnO₄

• The colour disappears due to dilution; no reaction is involved

•  KMnO₄ is an unstable compound and decomposes in presence of FeSO₄ to a colourless compound.

Answer 1

KMnO₄ is an oxidising agent and it oxidises FeSO₄

Explanation -

Potassium permanganate (KMnO₄) is an oxidising agent. It oxidises ferrous sulphate to ferric sulphate in the presence of dilute
H₂SO₄.

`underset("Purple")(2"KMnO"_4) + 8"H"_2"SO"_4 + 10"FeSO"_4 -> "K"_2"SO"_4 + 2"MnSO"_4 + 8"H"_2"O" + 5"Fe"_2("SO"_4)_3`

By taking part in the reaction, the light purple colour of the solution slowly fades and finally disappears.