A chemical reactor is used to produce ethylene oxide through the reaction of ethylene and oxygen. The reaction follows the following equation: C2H4 + 1.5 O2 C2H4O The reactor has a feed stream of 500 mol/h of ethylene and 750 mol/h of oxygen. If the reactor operates at a conversion of 60% and the selectivity of the reaction is 80%, what is the mass flow rate of ethylene oxide produced?