Consider a Galvanic cell constructed from the following half cells, linked by an external circuit and by a KCl salt bridge.
- an Al(s) electrode in 1.0 M Al(NO3)3 solution
- a Pb(s) electrode in 1.0 M Pb(NO3)2 solution
The balanced overall (net) cell reaction is
◦ Pb(s) + Al3+(aq) → Pb2+(aq) + Al(s.)
◦ 3Pb(s) + 2Al3+(aq) → 3Pb2+(aq) + 2Al(s).
◦ 3Pb2+(aq) + 2Al(s) → 3Pb(s) + 2Al3+(aq).
◦ Pb2+(aq) + Al(s) → Pb(s) + Al3+(aq).