Question

Pyrolusite is $Mn{O}_2$ used to prepare $KMn{O}_4$. Steps are:

$Mn{O}_2\underset{}{\overset{I}{\to }}Mn{O}_2^{2-}\underset{}{\overset{II}{\to }}Mn{O}_4^{-}$

Steps $I$ and $II$ are respectively:

• A. fuse with $KOH$/air, electrolyte oxidation.
• B. fuse with $KOH/K{NO}_3$, electrolyte oxidation.
• C. fuse with concentrated $H{NO}_3$/air, electrolytic reduction.
• D. dissolve in $H_{2}O$ oxidation.

Answer 1

Answer: (A), (B)

The correct options are
A fuse with $KOH$/air, electrolyte oxidation.
B fuse with $KOH/K{NO}_3$, electrolyte oxidation.

$KMn{O}_4$ + $KOH$+ $O_2$ $\to$ $2K_{2}Mn{O}_4$ +$2H_{2}O$

$Mn{O}_4^{2-}$ $\stackrel{Electrolyticoxidation}{\to }$ $Mn{O}_4^{-}$

$KMn{O}_4$ can be prepared from pyrolusite by fusing with $KOH$ in presence air or $KN{O}_3$ or any other strong oxidizing agent.

Hence,option A and B is correct.