# In basic medium,

Question:

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:

1. $(\mathrm{A}),(\mathrm{C})$ only

2. (A) only

3. (B) only

4. (A), (B) only

Correct Option: , 4

Solution:

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)