JAMB - Chemistry (2007 - No. 14)

A Daniell cell undergoes a redox reaction where zinc is oxidized at the anode, releasing electrons that travel through a circuit to the cathode where copper ions are reduced to solid copper, generating an electric current.

Oxidation half-reaction: Zinc metal (Zn) is oxidized to zinc ions (Zn\(^{2+}\)) at the anode, releasing electrons. Zn(s) → Zn\(^{2+}\) + 2e\(^-\)

Reduction half-reaction: Copper ions Cu\(^{2+}\) are reduced to solid copper metal (Cu) at the cathode, accepting electrons. Cu\(^{2+}\) + 2e\(^-\) → Cu

Overall reaction: Zn (s) + Cu\(^{2+}\) (aq) → Zn\(^{2+}\) (aq) + Cu (s).