A dilute ferrous sulphate solution was 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?

Options

A. `KMnO_(4)` is an oxidising agent, it oxidises `FeSO_(4)`
B. `FeSO_(4)` acts as an oxidising agent and oxidises `KMnO_(4)`.
C. The colour disappears due to dilution, no reaction is involved.
D. `KMnO_(4)` is an unstable compounds and decomposes in presence of `FeSO_(4)` to a colourless compound.

Answer

A

Explanation

A dilute ferrous sulphate solution was gradually added to the beaker containing acidified permanganate solution. A permanganate solution is usually purple in colour. The light purple colour of the solution fades and finally disappears. This is because potassium permanganate `(KMnO_(4))` is relatively an unstable compound, it tends to decompose in the presence of ferrous sulphate `(FeSO_(4))`. This changes the colour of the solution from purple to colourless. `FeSO_(4)` gets oxidised to `Fe_(2)(SO_(4))` as `KMnO_(4)` acts as a good oxidising agent in an acidic medium.