Which one is not a conductor of electricity?

An aqueous solution of $CuSO_{4}$ is subjected to electrolysis using inert electrodes. The $pH$ of the solution will

In the industrial production of which of the following,molecular hydrogen is obtained as a byproduct?

$NaOH$ is manufactured by the electrolysis of a brine solution. The products of the reaction are:

On passing electric current in an electrolyte solution,$H_2$ gas is liberated at the cathode. Then the electrolyte could be:

On electrolysis of aqueous solution of $KI$ in the presence of platinum electrodes,which of the following statements are correct?
$(a)$ Hydrogen gas is released at the cathode.
$(b)$ Oxygen gas is released at the anode.
$(c)$ $pOH$ of the solution decreases.
$(d)$ There is deposition of potassium at the cathode.