A vessel having a volume of 0.28m3 contains a mixture at 40oC, 6.9 bar with a molar analysis of 70% O2, 30% CH4. Determine the mass of methane that would have to be added and the mass of oxygen that would have to be removed, each in kg, to obtain a mixture having a molar fraction 30% O2, 70% CH4 at the same temperature and pressure. Answer: \Delta mO2 = -0.95 kg; \Delta mCH4 = 0.475 kg