Question

During electrolysis of aqueous solution of a salt pH in the space near one of the electrodes is increased. Which of the following salt solution was electrolysed?

• A. $KCl$
• B. $CuC{l}_2$
• C. $Cu(N{O}_3{)}_2$
• D. $CuS{O}_4$

Answer 1

The correct option is A

$KCl$

When $KCl$ is electrolysed, hydrogen gas is formed at the cathode:

$2H^{+}+2e^{-}\to H_2$

Since concentration of $H^{+}$ ions decreases, the pH increases.

Copper is below hydrogen in the activity series. In the other cases copper metal is formed over hydrogen gas being released.