Question

Consider the reactions:

(1) $H_{2}O_{2} + 2HI \rightarrow I_{2} + 2H_{2}O$

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

Which of the following statements is correct about $H_{2}O_{2}$with reference to these reactions?

Hydrogen peroxide is ___

• A. An oxidizing agent in both (1) and (2)
• B. An oxidizing agent in (1) and reducing agent in (2)
• C. A reducing agent in (1) and oxidizing agent in (2)
• D. A reducing agent in both (1) and (2)

Answer 1

Answer: (B)

An oxidizing agent in (1) and reducing agent in (2)

Answer 2

: (1) $H_{2}O_{2} + \overset{- 1}{2HI} \rightarrow \overset{0}{I_{2}} + 2H_{2}O$

Iodine is oxidised from -1 to 0 oxidation state thus,

$H_{2}O_{2}$acts as an oxidizing agent and itself gets reduced.

(2) $HO\overset{( + 1)}{Cl} + H_{2}O_{2} \rightarrow H_{3}O^{+} + Cl^{-} + O_{2}$

Chlorine is reduced from +1 to -1 oxidation state thus, $H_{2}O_{2}$acts as a reducing agent and itself gets oxidised.+