Question

Give reason why the pink colour of potassium permanganate solution fades with repeated dilution

Answer 1

Answer:

When potassium permanganate reacts with ethanol, it releases nascent oxygen. ie, an atom of oxygen thus converting the ethanol to acetic acid. Initially colour disappears because coloured permanganate ions of potassium permanganate are consumed to oxidise ethanol.

C2H5OH (WITH ALKALINE KMnO4)  CH3COOH+H2O

2)When excess is added colour does not change because there is no more alcohol left and hence there is no reaction

Answer 2

Explanation:

After few vol of kmno4 is let into the solution (fas or oxalic acid) the solution is indicated with the pink colour of the solution . dilution acts as a fact for the change in colour of solution . ... due to neutralisation reaction and compound formation with the titrand ions(ions of the solution in the burette).