A hydrogen-oxygen fuel cell is required to produce a constant voltage and operate over a pressure range of \(0.125-10\) bars. The datum voltage is \(1.16 \mathrm{~V}\) at a temperature of \(350 \mathrm{~K}\). If all the streams are at the same pressure evaluate the range of temperature required to maintain the voltage at this level, and show how the operating temperature must vary with pressure.

Assume that the enthalpy of reaction of the cell, \(Q_{\mathrm{p}}=-286,000 \mathrm{~kJ} / \mathrm{kmol} \mathrm{H}_{2}\), and that this remains constant over the full temperature range. The valency, \(z_{i}=2\).

[317.4 K]