JEE Main 2023 — Redox Reactions Question with Solution
From: JEE Main 2023 (Online) 10th April Evening Shift
Question
In alkaline medium, the reduction of permanganate anion involves a gain of __________ electrons.
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Step-by-step explanation
In alkaline medium, the reduction of permanganate anion involves a gain of 3 electrons.
The balanced chemical equation for the reduction of permanganate anion in alkaline medium is:
$ \begin{equation} \ce{MnO4^{-}(aq) + 3 e^{-} + 2 H2O(l) -> MnO2(s) + 4 OH^{-}(aq)} \end{equation}$In this reaction, the permanganate anion (MnO4-) is reduced to manganese dioxide (MnO2) by gaining 3 electrons. The water molecules (H2O) are oxidized by losing 2 electrons. The hydroxide ions (OH-) are spectator ions that do not participate in the redox reaction.
The reduction of permanganate anion in alkaline medium is a useful reaction for a variety of analytical and synthetic purposes. For example, it can be used to quantitatively determine the concentration of an analyte in a solution, or to synthesize a variety of organic compounds.
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