In which of the following half cells, electrochemical reaction is pH dependent?
Solution
Reduction of $\mathrm{MnO}_{4}^{-}$ is $\mathrm{pH}$ dependent.
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In acidic medium
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$\mathrm{MnO}_{4}^{-}+5 \mathrm{e}^{-} \longrightarrow \mathrm{Mn}^{2+}$
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In neutral medium
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$\mathrm{MnO}_{4}^{-}+3 \mathrm{e}^{-} \longrightarrow \mathrm{Mn}^{4+}$
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In basic medium
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$\mathrm{MnO}_{4}^{-}+\mathrm{e} \longrightarrow \mathrm{Mn}^{6+}$
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So, according to $\mathrm{pH}$, the reaction and potential of cell changes.
About this question
Subject: Chemistry · Chapter: Electrochemistry · Topic: Electrochemical Cells
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