In alkaline medium, the reduction of permanganate anion involves a gain of ____________ electrons.

Question

TestHub · Accepted Answer

In Faintly alkaline medium potassium permanganate changes to manganese dioxide in its oxidising action.

${MnO}_{4}^{-} + 2 H_{2} O + 3 e^{-} \overset{}{\to} {MnO}_{2} + 4 {OH}^{-}$

The oxidation state of manganese in ${MnO}_{4}^{-}$ is +7 and in ${MnO}_{2}$ is +4.

Hence, it transfers 3 electrons during the oxidising action in alkaline medium.

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