The aqueous solution of which of the following decomposes on passing electric current?

Explain: Oxidation of $Cl^{-}$ ion is carried out near the anode when electrolysis of aqueous (concentrated) $NaCl$ solution is carried out using an inert electrode.

Given below are two statements $:$
$1 \ M$ aqueous solution of each of $Cu(NO_3)_2, AgNO_3, Hg_2(NO_3)_2$ and $Mg(NO_3)_2$ are electrolysed using inert electrodes.
Given $: E_{Ag^{+}/Ag}^{\theta} = 0.80 \ V, E_{Hg_2^{2+}/Hg}^{\theta} = 0.79 \ V, E_{Cu^{2+}/Cu}^{\theta} = 0.24 \ V$ and $E_{Mg^{2+}/Mg}^{\theta} = -2.37 \ V$.
Statement $(I) :$ With increasing voltage,the sequence of deposition of metals on the cathode will be $Ag, Hg$ and $Cu$.
Statement $(II) :$ Magnesium will not be deposited at cathode instead oxygen gas will be evolved at the cathode.
In the light of the above statement,choose the most appropriate answer from the options given below.

If a current of $0.5 \ A$ flows through a metallic wire for $2 \ hours$,then how many coulombs would have flown through the wire (in $C$)?

Predict the products of electrolysis in each of the following:
$(i)$ An aqueous solution of $AgNO_3$ with silver electrodes.
$(ii)$ An aqueous solution of $AgNO_3$ with platinum electrodes.
$(iii)$ $A$ dilute solution of $H_2SO_4$ with platinum electrodes.
$(iv)$ An aqueous solution of $CuCl_2$ with platinum electrodes.

Which of the following substances conducts electricity?