The reaction below shows the combustion of propane (C3H8). Why is the mole ratio (3 moles CO2/1 mol C3H8) used to determine the amount of carbon dioxide (CO2) produced when propane (C3H8) combusts in excess oxygen? (1 point) C3H8 + O2 yields CO2 + H2O + heat Propane has a mass that is 3 times greater than that of CO2, so only 1 mole of C3H8 is needed to produce 3 moles of CO2. When the chemical equation for propane combustion is balanced, 1 mole of C3H8 is needed to produce 3 moles of CO2. During combustion, CO2 is approximately 3 times more reactive than C3H8, so less C3H8 will participate in the reaction. Carbon dioxide has a volume of about one-third that of C3H8, so 3 moles of CO2 are needed to react with each mole of C3H8.