Question

Which of the following is not correct regrading the electrolytic preparation of $H_2{O}_2$?

• A. Lead is used as cathode
• B. $50\%$ $H_{2}S{O}_4$ is used
• C. Hydrogen is liberated at anode
• D. Sulphuric acid undergoes oxidation.

Answer 1

Answer: (C)

Hydrogen is liberated at anode

$H_2{O}_2$ can be prepared by electrolysis of 50% $H_{2}S{O}_4$.

Here hydrogen is liberated at cathode

$H_2{SO}_4\rightleftharpoons 2H^{+}+{S{O}_4}^{2-}$

At anode:

$2{HS{O}_4}^{-}\rightleftharpoons H_2{S}_2{O}_8+2e^{-}$

$H_2{S}_2{O}_8+H_{2}O⟶2H_{2}S{O}_4+H_2{O}_2$

At cathode:

$2H^{+}+2e^{-}⟶H_2$