Determine the mole fractions and partial pressures of CO2,CH4, and He in a sample of gas that contains 1.35 moles of CO2,1.49 moles of CH4, and 3.91 moles of He, and in which the total pressure is 5.78atm. XCO2=PCO2=XCH4=PCH4=XHe=PHe=xxx