1. The problem statement, all variables and given/known data At 1 atm and 0° C, a 5.04 L mixture of methane (CH4) and propane(C3H8) was burned producing 20.9 g of CO2. Assume complete combustion. 1. How many moles total of methane and propane were present before combustion? 2. How many moles of carbon dioxide were present after the reactoin? 3. What was the mole fraction of each gas in the mixture? 2. Relevant equations PV = nRT 3. The attempt at a solution 1. PV = nRT n = 0.224743 moles of mixture 2. I converted 20.9 g CO2 to moles giving: 0.475 mol of CO2 3. This is where I'm stuck. First I balanced the combustion of the mixture: CH4 + C3H8 + 7O2 -> 4CO2 + 6H20 Then all I have is that 0.224743 mole of the mixture. I don't know how to find the number of moles of CH4 and C3H8 each so I can find the mole fraction.