Electrolysis is carried out in three cells : (A) - 1.0M CuSO4, Pt electrodes; (B) - 1.0 M CuSO4,, Copper electrode; (C) - 1.0 M KCl, Pt electrodes. If the volume of electrolytic solution is maintained constant in each of the cells, which is correct set of pH changes in (A), (B) and (C) cells respectively?
decrease, constant, increase
(A) Cathode:Cu2+(aq)+2e−→Cu(S)Anode:H2O→2H++12O2+2e−
pH decreases as the number of H+ ions increase.
(B) Cathode:Cu2+(aq)+2e−→Cu(s)Anode:Cu(s)→Cu2+(aq)+2e−
pH remains unchanged as the number of H+ remains unchanged.
(C) Cathode:2H2O+2e−→H2+2OH−(aq)Anode:2Cl−→Cl2(aq)+2e−
pH increases as the number of H+ ions decreases.