Question

How much electricity is required in coulomb for the oxidation of
a) 1 mol of $H_{2}O$ to $O_2$?
b) 1 mol of $FeO$ to $F{e}_2{O}_3$?

Answer 1

(a) $Eq.$ of $H_{2}O=\frac{i.t}{96500}$

$1$ mole $H_{2}O=2eq.$

$[2H_{2}O\to 4H^{+}+4e^{-}+O_2\therefore E_{H_{2}O}=\frac{M_{H_{2}O}}{2}]$

$2=\frac{i.t}{96500}$

$\therefore$ $i.t=96500\times 2C=2F$

(b) $Eq.$ of $FeO=\frac{i.t}{96500}$

$[2F{e}^{2+}\to F{e}_2^{3+}+2e\therefore E_{FeO}=M_{FeO}]$

$\therefore$ Valence factor for $FeO=1$

or $1=\frac{i.t}{96500}$

$i.t=96500C=1F$