Answer: 1. Pt serves as the cathode and Cd as the anode
2. Cd electrode loses mass as the cell reaction proceeds.
3. The overall cell reaction is mentioned in the explanation column.
Step-by-step explanation: 1. The electrode with positive reduction value serves as cathode, that is, Pt, while, the electrode with negative reduction value functions as anode, that is, Cd.
2. The oxidation takes place in the Cd electrode, which is anode, and it gets oxidized to Cd²⁺ (aq). Hence, Cd electrode loses mass as the cell reaction moves forward.
3. Cell reaction:
Cd(s) = Cd²⁺ (aq) + 2e⁻
Cl₂ (g) + 2e⁻ = 2Cl⁻ (aq)
Cd(s) + Cl₂(g) = Cd²⁺ (aq) + 2Cl⁻ (aq)