Question

How many faradays are required to reduce one mole of $Mn{O}_4^{-}$ to $M{n}^{2+}$?

• A. $1$
• B. $2$
• C. $3$
• D. $5$

Answer 1

The correct option is D $5$

The balanced chemical equation is:
$8H^{+}+5e^{-}+Mn{O}_4^{-}\to M{n}^{2+}+4H_{2}O$

As can be seen from the balanced chemical equation, to reduce one mole of $Mn{O}_4^{-}$ $5$ moles of electrons are required.
Hence,
$5mole{e}^{-}=5Faraday$.