Question

Calculate the electric current required to deposit 0.972 g of chromium in three hours. ECE of chromium is 0.00018 g/C.
1. 1 A
2. 100 A
3. 50 A
4. 0.5 A

Answer 1

Correct Answer - Option 4 : 0.5 A

If an electric current i is passed through an electrolyte for time t, the amount of charge passed is Q = it. And the amount of substance liberated at an electrode is m = Zit where Z is called as Electrochemical equivalent (ECE) of the substance (in kg/coulomb).

Here m = Zit

0.972 = 0.00018 × i × (3 × 3600)

i = 0.50 A