Electrolytic cell

Question

The quantity of electricity needed to separately electrolyze 1M solution of ZnSO4, AlCl3 and AgNO3 completely is in
the ratio of
(A) 2 : 3 : 1 (B) 2 : 1 : 1 (C) 2 : 1 : 3 (D) 2 : 2 : 1d

Answer 1

The charge required depends on how many electrons are needed to reduce each metal ion.

Zn²⁺ + 2e⁻ → Zn

Al³⁺ + 3e⁻ → Al

Ag⁺ + e⁻ → Ag

So for the same number of moles of each ion, the electricity required is proportional to:

2 : 3 : 1

Therefore, the answer is (A) 2 : 3 : 1.