The following hydrogen/oxygen fuel cell. The reactions are also shown for the anode and the cathode. The anodic and cathodic reactions are thus known in this problem. The load could, for instance, be an electric motor of a vehicle.

(a) Combine the two reactions seen at the cathode and consider the resulting reaction as your cathodic reaction. Then, find out an expression for in terms of activities of the reaction species. The activity of O-2 should not show up in the resulting equation for the cell voltage.

(b)Assuming that the activity coefficients are 1, simplify your equation.

(c) Does the increase or decrease as the partial pressure of H2 increases?

(d) There is something wrong with the figure. What is it?

Anode Cathode