Question

Which of the statement is incorrect about potassium permanganate?

• A. Potassium permanganate is a powerful oxidizing agent
• B. Potassium permanganate is a violet-black crystalline solid
• C. Potassium permanganate is stable in acidic medium
• D. Potassium permanganate can oxidize sulphites to sulphates

Answer 1

The correct option is C Potassium permanganate is stable in acidic medium

Permanganate in acidic medium:
$\left[Mn{O}_4{]}^{-}\right(aq)+8H^{+}(aq)+5e^{-}\to M{n}^{2+}(aq)+4H_{2}O(l)$
Half reactions:
$\left[Mn{O}_4{]}^{-}\right(aq)+e^{-}\to [Mn{O}_4{]}^{2-}\left(aq\right)$
$S{O}_3^{2-}\left(aq\right)+2O{H}^{-}\to S{O}_4^{2-}\left(aq\right)+H_{2}O\left(l\right)+2e^{-}$