Which of the following will give $H_{2(g)}$ at cathode and $O_{2(g)}$ at anode on electrolysis using platinum electrodes?

Which of the following pairs has easier reduction at the cathode?

Which of the following substances is an electrolyte?

Which one of the following metals could not be obtained on electrolysis of aqueous solution of its salts?

Which gas is produced during the preparation of $NaOH$?

On electrolysis of aqueous solution of $KI$ in presence of platinum electrodes:
$(a)$ Hydrogen gas is released at cathode
$(b)$ Oxygen gas is released at anode
$(c)$ $pOH$ of solution decreases
$(d)$ There is deposition of potassium at cathode
Choose the correct option from following