2.7 Consider a 300-plate fuel cell stack with 150 cm² active area per plate:S 2.5 (a) For an anode and a cathode stoichiometry of 1.4 and 2.5, respectively, determine the mass flow rate of hydrogen and air into the fuel cell per ampere of current. (b) If the nominal operating point is an average of 30 0.6 V per plate with 1.2 A/cm², determine the stack voltage and electrical power output. (c) How much total electrical work at 0.6 V per plate could be performed with a storage tank contain- ing 5 kg of hydrogen and limitless air? How much more output could be achieved if the unused fuel were recycled so that the effective fuel utilization became 100%. (d) Determine how many plates the fuel cell would have to have at 0.6 V per plate, 1.2 A/cm², to generate 150 horsepower for an automotive appli- cation. P-TV