Question

In the electrolysis of an aqueous potassium sulphate solution, the pH of the solution in the space near an electrode increased. Which pole of the current source is the electron connected to?

• A. The positive pole
• B. Could be either pole
• C. The negative pole
• D. Cannot be determine

Answer 1

The correct option is A The positive pole

Given: Electrolysis of aqueous potassium sulphate solution:

$K_{2}S{O}_4\leftrightharpoons 2K^{+}+S{O}_4^{2-}$

$H_{2}O\leftrightharpoons H^{+}+O{H}^{-}$

Reaction at anode $=2O{H}^{-}\to H_{2}O+1/2O_2+2e^{-}$

Reaction at cathode $=2H^{+}+2e^{-}\to H_{2}O$

$H^{+}$ concentration is decreasing with time so $pH$ goes on increasing at cathode electrode.

Hence option A is correct.