Question
(a) Calculate 
for the reaction
Mg (s) + Cu2+ (aq) → Mg2+ (aq) + Cu (s)
Given : E°cell = + 2.71 V, 1 F = 96500 C mol−1
(b) Name the type of cell which was used in Apollo space programme for providing electrical power.
Solution
(a) For the cell reaction,
Mg (s) + Cu2+ (aq) → Mg2+ (aq) + Cu (s) E°cell = + 2·71 V
The change in the standard Gibbs free energy is given as:
= −nFE°cel. = −2 x 96500 x 2.71 = -523030 Jmol−1
b) The fuel cell which uses the reaction of hydrogen with oxygen to form water was used in Apollo space programme for providing electrical power.
