about material balance

Ethylene oxide is produced by the catalytic oxidation of Ethylene: An undesired competing 22H4+O22C2H4O An undesired competing reaction is the combustion of Ethylene: C2H4+3O22CO2+2H2O The feed to the reactor contains 3 moles of ethylene per mole of oxygen. The single-pass conversion of ethylene is 20%, and for every 100 moles consumed in the reactor, 90 moles of ethylene oxide emerges in the reactor products. A multiple unit process is used to separate the products: ethylene and oxygen are recycled to the reactor, ethylene oxide is sold as a product, and carbon dioxide and water are discarded. Assume a quantity of the reactor feed stream as a basis of calculation, draw and label the flowchart, perform a degree-of-freedom analysis for the reactor using atomic species balances, and write the equations you would use to calculate (i) the molar flow rates of ethylene and oxygen in the fresh feed, (ii) the production rate of ethylene oxide, and (iii) the overall conversion of ethylene