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

An aqueous solution containing $1 \ M$ each of $Cu(NO_3)_2$,$AgNO_3$,$Hg_2(NO_3)_2$,and $Mg(NO_3)_2$ is electrolyzed using inert electrodes. Given the standard reduction potentials: $E^{\circ}_{Ag^+/Ag} = 0.80 \ V$,$E^{\circ}_{Hg_2^{2+}/2Hg} = 0.79 \ V$,$E^{\circ}_{Cu^{2+}/Cu} = 0.34 \ V$,and $E^{\circ}_{Mg^{2+}/Mg} = -2.37 \ V$. What is the correct order of deposition of metals at the cathode?

The passage of current liberates $H_2$ at cathode and $Cl_2$ at anode. The solution is

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

$A$ solution of $Na_2SO_4$ in water is electrolysed using inert electrodes. The products at cathode and anode are respectively

Which of the following is a property of a solution of dry hydrogen chloride in dry methylbenzene?