Question

metallic Potassium is not librated at the cathode when an aqueous solution of k2So4 is electrolysed explain​

Answer 1

Answer:

2H

2

O→2H

2

+O

2

.

Thus, out of 1.68 L of gases

3

1.68

=0.56 moles of oxygen and 1.12 moles of hydrogen are obtained.

The reaction at cathode is 2H

2

O+2e

−

→H

2

+2OH

−

Thus, 1 mole of hydrogen gas (or 22.4 L at STP) corresponds to 2 faraday of electrons.

Hence, 1.12 L of hydrogen gas will correspond to

22.4

1.12

=0.05 moles of hydrogen or 2×0.05=0.10 moles of electrons.

MnO

4

−

+5e

−

→Mn

2+

0.1 moles of electrons can reduce

5

0.10

=0.02 moles of MnO

4

−

ions to Mn

2+

ions.