Chemistry - Electrochemistry Question with Solution | TestHub

Given:
Current, $I=10$ A
Time, $t=109$ min $=109\times 60$ s $=6540$ s
Molar mass of Co $=59$ g/mol

In cobalt chloride (${\text{CoCl}}_2$), the valency of cobalt is $2$. The reduction reaction is:
${\text{Co}}^{2+}+2e^{-}\to \text{Co}$

Equivalent mass of Co, $E=\frac{\text{Molar mass}}{\text{Valency}}=\frac{59}{2}=29.5$ g/eq

Total charge passed, $Q=I\times t=10\times 6540=65400$ C

According to Faraday's first law of electrolysis, the mass of cobalt deposited is:
$W=\frac{E\times Q}{96500}$

$W=\frac{29.5\times 65400}{96500}$

$W=\frac{1929300}{96500}\approx 19.99$ g

Rounding off, the mass of cobalt deposited is $20.0$ g.

Answer: $20.0\text{g}$