Hydrogen peroxide is a powerful oxidising agent, both in the acidic and alkaline medium.
In acidic medium: `H_(2)O_(2)+2H^(o+)+2e^(ɵ)to2H_(2)O`
In alkaline medium: `H_(2)O_(2)+2e^(ɵ)to2overset(Theta)(O)H`
Hydrogen peroxide acts as a reducing agent towards powerful oxidising agents.
In acidic medium: `H_(2)O_(2)to2H^(o+)+O_(2)+2e^(ɵ)` In alkaline medium, however, its reducing nature is more effective.
`H_(2)O_(2)to2H^(o+)+O_(2)+2e^(ɵ)`
In which of the following reactions, `H_2O_2` act as a reducing agent?

Options

A. `PbO_(2)(s)+H_(2)O_(2)(aq) rarr PbO(s)+H_(2)O(l)+O_(2)(g)`
B. `Na_(2)SO_(3)(aq)+H_(2)O_(2)(aq)rarrNa_(2)SO_(4)(aq)+H_(2)O(l)`
C. `2KI(aq)+H_(2)O_(2)(q)rarr 2 KOH(q)+I_(2)(s)`
D. `KNO_(2)(aq)+H_(2)O_(2)(aq) rarr KNO_(3)(aq)+H_(2)O(l)`

Answer

a

Explanation

In the following reaction, `H_(2)O_(2)` acts as a reducing agent.
`PbO_(2)(s)+H_(2)O(aq) rarr PbO(s)+H_(2)O(l)+O_(2)(g)`