Q. A current of 12 A is passed through an electrolytic cell containing aqueous $N{iSO}_{4}$ 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
Explanation
(a)
${Ni}^{-} + \ {2e}^{-}\ \rightarrow Ni\ (at\ cathode)$
Equivalent weight of $Ni\ = \ \frac{mol.wt.}{gain\ electron}$
$= \ \frac{58.7}{2}$
= 29.35
$i = 12A,\ t = 1h\ = \ 60\ \times \ 60s.,$
$Z = \ \frac{eq.wt.}{96500}$
$\ Weight\ of\ deposit\ Ni\ = \ \frac{Zit\ \times efficiency}{100}$
$= \ \frac{29.35\ \times 12\ \times 60\ \times 60\ \times 60}{96500\ \times 100}\$
= 7.883 g
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.