a Q2: Compressed propane (CzHx) has been suggested as a source of economic power for vehicles. Suppose that in a test 20 lb of C3Hg is burned with 400 lb of air to produce 44 lb of CO2 and 12 lb of CO. What was the percent excess air? M.Wt data: air = 29, C3Hg = 44. - )