Question

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

• A. 8
• B. 80
• C. 10
• D. 16

Answer 1

Answer: (A)

$Ca ^{2+}+2 e ^{-} \longrightarrow Ca ($ atcathode $)$

$1\, mol \,\,\,\,\,CaCl _{2}=2 F$

From $Q=$ it

$n \cdot 2 F = it$

$t=\frac{n .2 F}{i}$

$=\frac{30}{40} \times \frac{2 \times 96500}{5}$

$=28950\, s$

$=\frac{28950}{60 \times 60} \,h$

$=8.04 \,h$