Cosider the reactions
(i) `H_(2)O_(2) + 2HI to I_(2) + 2H_(2)O`
(ii) `HOCl + H_(2)O_(2) to H_(3)O^(+) + Cl^(-) + O_(2)`
Which of the following statements is correct about `H_(2)O_(2)` with reference to these reactions ? Hydrogen peroxide is ………

Options

A. an oxidising agent in both (A) and (B)
B. an oxidising agent in (A) and reducing agent in (B)
C. a reducing agent in (A) and oxidising agent in (B)
D. a reducing agent in both (A) and (B)

Answer

B

Explanation

The rule of thumb for oxidising-reducing hebaviour of `H_(2)O_(2)` is :` H_(2)O_(2) ` acts as a reducing agent if `O_(2)` is evolved and `H_(2)O_(2)` acts as an oxidising agent if `O_(2)` is not evolved.
Thus, in reaction (A), `H_(2)O_(2)` acts as an oxidising agent since `O_(2)` is not evolved but in reaction (B), it acts a reducing agent because `O_(2)` is evolved , i.e., option (b) is correct.