During the electrolysis of aqueous solution of the following, molarity of the solution increases without changing the chemical composition
 

At cathode (Reduction takes place):

$2{\mathrm{H}}^{+}+2{\mathrm{e}}^{-}\to {\mathrm{H}}_{2_{\left(\mathrm{g}\right)}}$

At anode (Oxidation takes place):

${\mathrm{H}}_2\mathrm{O}\to 2{\mathrm{H}}^{+}+\frac{1}{2}{\mathrm{O}}_2+2{\mathrm{e}}^{-}$

Therefore, H₂SO₄ composition remains the same.

Water composition decreases.