2. The cell diagram of a silver-zinc cell is:
Zn(s), ZnO(s)|KOH(satd)|Ag2O(s), Ag(s)
The half reactions on discharging are:
Reduction: Ag2O(s) + H2O(l) + 2e- 2 Ag(s) + 2OH-(aq)
Oxidation: Zn(s) + 2OH-(aq) ZnO(s) + H2O(l) + 2e-
Overall: Zn(s) + Ag2O(s) ZnO(s) + 2 Ag(s)

3. Characteristics:
0Because no solution species is involved in the cell
reaction, the quantity of electrolyte is very small and
electrode can be maintained very close together.
0Cell voltage is 1.8 V
0Storage capacity is six times greater than that of a
lead-acid battery of the same size
Uses:
0These characteristics make batteries such as silver
zinc cell useful in button batteries. These miniature
batteries are used in watches, hearing aids and
cameras.

4. 0 Silver-zinc batteries fulfill the requirements of spacecraft,
satellites, missiles, rockets, space launch vehicles, torpedoes,
underwater vehicles and life support systems
0 On the Mars Pathfinder mission, the rover and the cruise
system were powered by solar cells. The energy storage
requirements of the lander were met by modified silver-zinc
batteries with about three times the storage capacity of the
standard nickel-cadmium rechargeable battery