Ncert Exercises & Solutions

Consider the reactions

(i) $H_{2} O_{2} + 2 HI \to I_{2} + 2 H_{2} O$

(ii) $HOCl + H_{2} O_{2} \to H_{3} O^{+} + {Cl}^{-} + O_{2}$

Which of the following statements is correct about H₂O₂ with reference to these reactions? Hydrogen peroxide is ______.

1. an oxidising agent in both (i) and (ii)

2. an oxidisng agent in (i) and reducing agent in (ii)

3. a reducing agent in (i) and oxidising agent in (ii)

4. a reducing agent in both (i) and (ii)

Hint: Loss of electrons oxidation and gain of electrons reduction

In the first reaction, oxidation of I is change from -1 to 0. HI undergo oxidation reaction.

Thus, here H₂O₂ oxidises HI into I₂ hence, it behaves as oxidising agent.

In the second reaction, oxidation of Cl is change from +1 to -1. HOCl undergo reduction reaction.

Here, H₂O₂ reduces to HOCl to Cl^-1, thus, it acts as reducing agent.