write balanced chemical equations for the cathode and anode half-reactions and the overall cell reaction. Include the phases of all species in the chemical equation.

Question

Sometimes the cell reaction of nickel-cadmium batteries is written with Cd metal as the anode and solid NiO₂ as the cathode. Assuming that the products of the electrode reactions are solid hydroxides of Cd(II) and Ni(II), respectively, write balanced chemical equations for the cathode and anode half-reactions and the overall cell reaction. Include the phases of all species in the chemical equation.

A. Cathode

B. Anode

C. Overall Cell Reaction

Answer 1

Anode: Cd(s) + 2OH^-(aq) ==> Cd(OH)₂(s) + 2e-

Cathode: NiO₂(s) + 2H₂O(l) + 2e- ==> Ni(OH)₂(s) + 2OH^-(aq)

Overall: Cd(s) + NiO₂(s) + 2H₂O(l) ==> Cd(OH)₂(s) + Ni(OH)₂(s)