Question

What type of reactions do occur at the two electrodes at a galvanic cell and what is the nature of the net cell reaction? Explain with an example.

Answer 1

The net cell reaction in a galvanic cell is a redox reaction. It involves oxidation at the anode and reduction at the cathode. This redox reaction is spontaneous, and it results in the conversion of chemical energy into electrical energy.

In the daniell cell, zinc and copper electrodes are used.

At anode (oxidation): \[\ce{Zn_{(s)} -> Zn{^{2+}_{(aq)}} + 2e-}\]

At cathode (reduction): \[\ce{Cu{^{2+}_{(aq)}} + 2e- -> Cu_{(s)}}\]

Net cell reaction: \[\ce{Zn_{(s)} + Cu{^{2+}_{(aq)}} -> Zn{^{2+}_{(aq)}} + Cu_{(s)}}\]

This net redox reaction is spontaneous and drives the flow of electrons from zinc (anode) to copper (cathode) through the external circuit.