Question

The quantity of electricity needed to separately electrolyse 1 M solution of ZnSO₄, AlCl₃, and AgNO₃ completely is in the ratio of ______.

Options

• 2 : 3 : 1

• 2 : 1 : 1 

• 2 : 1 : 3

• 2 : 2 : 1

Answer 1

The quantity of electricity needed to separately electrolyse 1 M solution of ZnSO₄, AlCl₃, and AgNO₃ completely is in the ratio of 2 : 3 : 1.

Explanation:

In ZnSO₄, \[\ce{\underset{(1 mol)}{Zn^{2+} +} 2e- \underset{(2 mole)}{-> Zn}}\]

                                or
                         (2 faraday)

In AlCl₃, \[\ce{\underset{1 mol}{Al^{3+}} + \underset{3F}{3e-} -> Al}\]

In AgNO₃; \[\ce{\underset{1 mol}{Ag+} + \underset{1F}{e-} -> Ag}\]

Thus; The ratio the amounts of electricity required is 2 : 3 : 1.