In an industry, ethylene oxide is produced by oxidation of ethylene with air in the presence of a catalyst. If conditions are carefully controlled, a fraction of the ethylene is converted to ethylene oxide, while part of the ethylene remains unreacted, and another part undergoes complete oxidation to CO2 and H2O. The formation of CO is negligible. The gases after leaving the reactor pass through an absorber in which the ethylene oxide is retained. A standard Orsat analysis of the gases leaving the absorber gives: 9.6% CO2, 3% O2 and 6.4% CH2 = CH2. Of the ethylene that enters the reactor, what percentage is converted to ethylene oxide? And what is the selectivity of the plant? The system operates in a continuous and stationary regime. CH 2 = CH 2 + 21 O 2 O C H 2 C H 2 CH2 =CH2 +3O2 2CO2 +2H2O