Question

In which of the following reactions, hydrogen peroxide acts as an oxidizing agent?

• A. $\text{H}\text{O}\text{C}\text{l}+\text{H}_{2}\text{O}_{2} \rightarrow \text{H}_{3}\text{O}^{+}+\text{C}\text{l}^{-}+\text{O}_{2}$
• B. $\text{I}_{2}+\text{H}_{2}\text{O}_{2}+2\text{O}\text{H}^{-} \rightarrow 2\text{I}^{-}+2\text{H}_{2}\text{O}+\text{O}_{2}$
• C. $\text{P}\text{b}\text{S}+4\text{H}_{2}\text{O}_{2} \rightarrow \text{P}\text{b}\text{S}\text{O}_{4}+4\text{H}_{2}\text{O}$
• D. $2\text{M}\text{n}\text{O}_{4}^{-}+3\text{H}_{2}\text{O}_{2} \rightarrow 2\text{M}\text{n}\text{O}_{2}+3\text{O}_{2}+2\text{H}_{2}\text{O}+2\text{O}\text{H}^{-}$

Answer 1

Answer: (C)

$2 e ^{-}+2 H ^{+}+ H _{2} O _{2} \longrightarrow 2 H _{2} O \quad$ (reduction)

$S ^{-2}+4 H _{2} O \longrightarrow SO _{4}^{-2}+8 H ^{+}+8 e ^{-}($ oxidation $)$

(Equation. $1 \times 4$ ) $+$ (Equation. 2 )

Final reaction $PbS +4 H _{2} O _{2} \longrightarrow PbSO _{4}+4 H _{2} O$