Question

Alkaline oxidative fusion of $MnO_2$ gives “A” which on electrolytic oxidation in alkaline solution produces B. A and B respectively are:

• A. Mn$_2$O$_7$ and MnO$_4^-$
• B. MnO$_4^{2-}$ and MnO$_4^-$
• C. Mn$_2$O$_3$ and MnO$_4^{2-}$
• D. MnO$_4^{2-}$ and Mn$_2$O$_7$

Answer 1

Answer: (B)

MnO$_4^{2-}$ and MnO$_4^-$

Answer 2

The process described involves the oxidative reactions of manganese compounds in alkaline solutions.

Alkaline Oxidative Fusion of $MnO_2$: When $MnO_2$ is subjected to oxidative fusion in an alkaline medium, it can form $MnO_4^{2-}$ (manganate ion) under alkaline conditions. The reaction can be represented as:

$2MnO_2 + 2OH^- + O_2 \rightarrow 2MnO_4^{2-} + H_2O$.

Electrolytic Oxidation of Product A: The product A formed from the oxidative fusion of $MnO_2$ can be oxidized electrolytically in alkaline solution to form $MnO_4^-$ (permanganate ion). The overall reaction is:

$MnO_2 + 2e^- \rightarrow MnO_4^-$.

Thus, the products A and B formed in the given reaction sequence are: A = $MnO_4^{2-}$ and B = $MnO_4^-$.