Question

Consider the reactions :
$(A)\,H_2O_2 + 2HI \to I_2 + 2H_2O$
$(B)\,HOCl + H_2O_2 \to H_3O^+ + Cl^- + O_2$
Which of the following statements is correct about $H_2O_2$ with reference to these reactions? Hydrogen peroxide is_________.

• 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 1

Answer: (B)

Iodine is oxidised from $-1$ to $0$ oxidation state thus, $H_2O_2$ acts as an oxidising agent and itself gets reduced.

Chlorine is reduced from $+1$ to $-1$ oxidation state thus, $H_2O_2$ acts as a reducing agent and itself gets oxidised.