Question

When $0.1$ mole of $MnO_4^{2-}$ is oxidised, the quantity of electricity required to completely oxidise $MnO_4^{2-}$ to $MnO_4^{-} $ is

• A. 96500 C
  
• B. $2 \times 96500 \, C $
  
• C. 9650 C
  
• D. 96.50 C
  

Answer 1

Answer: (C)

The oxidation reaction is as shown below.
$MnO _{4}^{2-}+ e ^{-} \rightarrow MnO _{4}^{-}$
Oxidation of one mole of $MnO _{4}^{2-}$ requires $1$ mole of electrons.
Hence, the oxidation of $0.1$ mole of electrons will require $0.1$ mole of electrons.
This corresponds to $96500 \times 0.1=9650 C$.