Question

A current of $12$ ampere is passed through an electrolytic cell containing aqueous $ NiS{{O}_{4}} $ solution. Both $Ni$ and $ {{H}_{2}} $ gas are formed at the cathode. The current efficiency is $60\%$. What is the mass of nickel deposited on the cathode per hour?

• A. $7.883\, g$
• B. $3.941\, g$
• C. $5.91\, g$
• D. $2.645\, g$

Answer 1

Answer: (A)

$N i^{-}+2 e^{-} \rightarrow N i$ (at cathode)
Equivalent weight of $N i=\frac{\text { mol.wt }}{\text { gain electron }}$
$=\frac{58.7}{2}$
$=29.35$
$i=12 A, t=1 h$
$=60 \times 60 s, Z$
$=\frac{E q u . w t .}{96500}$
Weight of deposite $N i=\frac{\text { Zit } \times \text { efficiency }}{100}$
$=\frac{29.35 \times 12 \times 60 \times 60 \times 60}{96500 \times 100}$
$=7.883 g$