JEE Main · 2022 · 29 Jun 2022 · Shift 1 · Hydrogen

Which one of the following reactions indicates the reducing ability of hydrogen peroxide in basic medium ?

(A) $HOCl + H_{2} O_{2} \to H_{3} O^{+} + Cl^{-} + O_{2}$
(B) $PbS + 4 H_{2} O_{2} \to PbSO_{4} + 4 H_{2} O$
(C) $2 MnO_{4}^{-} + 3 H_{2} O_{2} \to 2 MnO_{2} + 3 O_{2} + 2 H_{2} O + 2 OH^{-}$ ✓ Correct
(D) $Mn^{2 +} + H_{2} O_{2} \to Mn^{4 +} + 2 OH$

Answer: (C)

Solution

For

H_{2} O_{2}

to act as a reducing agent, it must be oxidized, i.e., it should produce

O_{2}

.

Examining the options:

(A) produces $O_{2}$ but contains $H_{3} O^{+}$ , indicating acidic medium.
(B) is an oxidizing reaction (no $O_{2}$ formed).
(C) produces $O_{2}$ and contains $OH^{-}$ , indicating basic medium. Here, $H_{2} O_{2}$ reduces $MnO_{4}^{-}$ to $MnO_{2}$ while being oxidized to $O_{2}$ .
(D) shows oxidizing behavior (no $O_{2}$ formed).

Only option (C) shows the reducing ability of

H_{2} O_{2}

in basic medium.

Answer: (C)

JEE Main · 2022 · 29 Jun 2022 · Shift 1 · Single correct option