The approximate time duration in hours to electroplate 30g of calcium from molten calcium chloride using a current of 5 amp is: [At. Mass of Ca=40]

According to Faraday’s first law of electrolysis, W = Z x i x t = $\frac{\text{ Eq.wt }}{96500}\times \mathbf{i}\times \mathbf{t}$
Here, W = 30 g i = 5A
Eq. wt. of Ca $=\frac{\text{ Atomic wt. }}{\text{ Valency }}=\frac{40}{2}=20$
$\begin{array}{l}\therefore 30=\frac{20}{96500}\times 5\times \mathrm{t}\left(\text{ or }\right)\\ \mathrm{t}=\frac{96500\times 30}{5\times 20}=28950\mathrm{S}\\ \frac{28950}{60\times 60}\mathrm{h}=8.04\mathrm{h}\end{array}$