Q.

An aqueous solution of AgNO3 with silver electrode, when undergoes electrolysis, two oxidation and two reduction half-reactions must be considered.Oxidation (at anode) (A) Ag(s)⟶Ag+(aq)+e-;E°=-0.80 V (B) 2H2O(l)⟶O2(g)+4H+(aq)+4e-;E°=-1.23 VReduction (at cathode) (C) Ag+(aq)+e-⟶Ag(s);E°=+0.80 V (D) 2H2O(l)+2e-⟶H2(g)+2OH-(aq);E°=-0.83 VBy E° values of (A ) and (B ) it appears that at anode silver of silver anode gets oxidized more readily because oxidation potential of Ag is greater than that of H2Omolecule. Similarly by E° values of (C) and (D), it appears that at cathode reduction potential of Ag+ ions is higher than that of H2O molecules. Therefore, on electrolysis of aq. AgNO3 solution with silver electrodes, Ag from silver anode dissolves while Ag+(aq) ions present in the solution get reduced and deposited at cathode.