Acetylene is hydrogenated to form ethane. The feed to the reactor contains 1.50mol H₂/mol C₂H₂.

(a) Calculate the stoichiometric reactant ratio (mol H₂ react/mol C₂H₂ react) and the yield ratio (k mol C₂H₆ formed/k mol H₂ react).

(b) Determine the limiting reactant and calculate the percentage by which the other reactant is in excess.

(c) Calculate the mass feed rate of hydrogen (kg/s) required to produce 4 x 10⁶ metric tons of ethane per year, assuming that the reaction goes to completion and that the process operates for 24 hours a day, 300 days a year.

(d) There is a definite drawback to running with one reactant in excess rather than feeding the reactants in stoichiometric proportion. What is it?