In basic medium, $\mathrm{H}_{2} \mathrm{O}_{2}$ exhibits which of the following reactions?
(A) $\mathrm{Mn}^{2+} \rightarrow \mathrm{Mn}^{4+}$
(B) $\mathrm{I}_{2} \rightarrow \mathrm{I}^{-}$
(C) $\mathrm{PbS} \rightarrow \mathrm{PbSO}_{4}$
Choose the most appropriate answer from the options given below:
Correct Option: , 4
In basic medium, oxidising action of $\mathrm{H}_{2} \mathrm{O}_{2}$
$\mathrm{Mn}^{2+}+\mathrm{H}_{2} \mathrm{O}_{2} \rightarrow \mathrm{Mn}^{44}+2 \mathrm{OH}$
In basic medium, reducing action of $\mathrm{H}_{2} \mathrm{O}_{2}$
$\mathrm{I}_{2}+\mathrm{H}_{2} \mathrm{O}_{2}+2 \mathrm{OH}^{-} \rightarrow 2 \mathrm{I}^{-}+2 \mathrm{H}_{2} \mathrm{O}+\mathrm{O}_{2}$
In acidic medium, oxidising action of $\mathrm{H}_{2} \mathrm{O}_{2}$
$\mathrm{PbS}(\mathrm{s})+4 \mathrm{H}_{2} \mathrm{O}_{2}(\mathrm{aq}) \rightarrow \mathrm{PbSO}_{4}(\mathrm{~s})+4 \mathrm{H}_{2} \mathrm{O}(\ell)$
Hence correct option (d)