Question

A certain amount of current liberates $0.5g$ of hydrogen in 2 hours. How many grams of copper can be produced by the same current flowing for the same time in copper sulphate solution?

Answer 1

By Faradays second law of electrolysis,
If equal amount of charge (Q) is passed through two different solutions, the amount of substance deposited/liberated (W) is proportional to their chemical equivalent weights (E).

Thus,
$\frac{W_1}{W_2}=\frac{E_1}{E_2}=\frac{Z_1}{Z_2}$

$\frac{\text{Weight of Cu}}{\text{Weight of}{H}_2}=\frac{\text{Equivalent weight of Cu}}{\text{Equivalent weight of}{H}_2}$

$\frac{\text{Weight of Cu}}{0.504}=\frac{63.5/2}{2/2}$
$\text{Weight of Cu}=16g$