The galvanic cell corresponding to the given redox reaction can be represented as:

(i) Zn electrode is negatively charged because at this electrode, Zn oxidizes to ${\mathrm{Zn}}^{2+}$  and the leaving electrons accumulate on this electrode.
(ii) Ions are the carriers of current in the cell.
(iii) The reaction taking place at Zn electrode can be represented as:

${\mathrm{Zn}}_{\left(\mathrm{s}\right)}\to {{\mathrm{Zn}}^{2+}}_{\left(\mathrm{aq}\right)}+2{\mathrm{e}}^{-}$

And the reaction taking place at Ag electrode can be represented as:

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

(iv) In aqueous solutions,${\mathrm{CuCl}}_2$  ionizes to give ${\mathrm{Cu}}^{2+} \mathrm{and} {\mathrm{Cl}}^{-}$ions as:

${\mathrm{CuCl}}_{2\left(\mathrm{aq}\right)}\to {{\mathrm{Cu}}^{2+}}_{\left(\mathrm{aq}\right)}+2{{\mathrm{Cl}}^{-}}_{\left(\mathrm{aq}\right)}$

On electrolysis, either of ${\mathrm{Cu}}^{2+}$ ions or ${\mathrm{H}}_2\mathrm{O}$ molecules can get reduced at the cathode. But the reduction potential of ${\mathrm{Cu}}^{2+}$ is more than that of ${\mathrm{H}}_2\mathrm{O}$molecules.

Hence, Cu2+ ions are reduced at the cathode and get deposited.
Similarly, at the anode, either of ${\mathrm{Cl}}^{-}$ or ${\mathrm{H}}_2\mathrm{O}$ is oxidized. The oxidation potential of ${\mathrm{H}}_2\mathrm{O}$ is higher than that of ${\mathrm{Cl}}^{-}$.

But oxidation of ${\mathrm{H}}_2\mathrm{O}$ molecules occurs at a lower electrode potential than that of ${\mathrm{Cl}}^{-}$ ions because of over-voltage (extra voltage required to liberate gas). As a result, ${\mathrm{Cl}}^{-}$ ions are oxidized at the anode to liberate ${\mathrm{Cl}}_2$ gas.