Consider the following diagram in which an electrochemical cell is coupled toan electrolytic cell. What will be the polarity of electrodes ‘A’ and ‘B’ in the electrolytic cell?

By convention, anode is placed on left and cathode is placed on the right. Oxidation occurs at anode and reduction occurs at the cathode.

Redox reaction for the cell is

Zn(s) + Cu²⁺→Zn²⁺(aq) + Cu(s)

Anode- oxidation half-cell: Zn(s) → Zn²⁺ (aq)+ 2e^-

Cathode- reduction half-cell: Cu²⁺ (aq)+ 2e^-→ Cu(s)

Zinc goes into solution as Zn²⁺ and leaves behind the electrons on Electrode A making it negatively charged. Cu²⁺ from the solution deposits on Electrode B making it positively charged.

Electrode A polarity- negative

Electrode B polarity- positive