Question

$K_{2}Mn{O}_4$ in acidic or neutral medium undergo disproportionation reaction to give

• A. $Mn{O}_4^{-}$ and $Mn{O}_2$
• B. Only $Mn{O}_4^{-}$
• C. Only $M{n}_2{O}_4^{2-}$
• D. $Mn{O}_4^{-}$ and $M{n}_2{O}_4^{2-}$

Answer 1

The correct option is A $Mn{O}_4^{-}$ and $Mn{O}_2$

Disproportionation reaction of managanate in acidic or neutral medium is one of the preparation method for the permanaganate.

$3Mn{O}_4^{2-}+4H^{+}\to \underset{\text{Dark purple}}{2Mn{O}_4^{-}}+Mn{O}_2+2H_{2}O$

Here, $M{n}^{6+}$ is disproportionate to $M{n}^{7+}$ and $M{n}^{4+}$

Hence, option (a) is correct.