Q. If 96500 $coulombs$ of electricity liberates one gram equivalent of any substance, the time taken for a current of $0.15\ amperes$ to deposit $20mg$ of copper from a solution of copper sulphate is (Chemical equivalent of copper = 32)
A) $5\min{20\ sec}$
B) $6\min{42\ sec}$
C) $4\min{40\ sec}$
D) $5\min{50\ sec}$
Explanation
(b) $m = Z\ i\ t\ \Rightarrow 20 \times 10^{- 3} = \left( \frac{32}{96500} \right) \times 0.15 \times t$
$= 6.7\ min = 6\ min.42\ sec$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.