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

$A$ solution of sodium sulphate in water is electrolysed using platinum electrodes. The products at cathode and anode are respectively

Write the reactions for the following electrolytic processes:
$A$. Electrolytic reaction of concentrated aqueous solution of $NaCl$ (Brine).
$B$. Electrolytic reaction of dilute aqueous solution of $NaCl$.

How many moles of electrons are required for the reduction of $1 \ mole$ of $Cr^{3+}$ to $Cr_{(s)}$?

The electrolytic decomposition of dilute sulphuric acid with $Pt$ electrodes in the cathodic reaction is:

The product obtained at the anode when $50 \%$ $H_2SO_4$ aqueous solution is electrolysed using platinum electrodes is: