From the stoichiometry of the overall reaction, we find that the 5 moles/
s of H2 converted in the anode must be matched by 2.5 moles/s of O2
consumed in the cathode. Since 10.6 moles/s of O2 are fed and 2.5 mole/
s are consumed, 8.1 moles/s of O2 must exit. Thus, the oxygen utilization
(i.e., conversion of oxygen) is calculated as