Question

In a combustion device, a mixture of 82 lbs of butane and 212 lbs propane C3H8 are burned with just enough air for complete combustion. How many lbs of total combustion products are formed? Round your answer to the nearest whole number

Answer 1

The combustion of butane with molar mass

2C4H10 + 13(O2 + 3.75N2)? 8CO2 + 10H2O + 48.75N2

MM 58 32 28 44 18 28

From the stoichiometry of the reaction

(2*58 =) 116 lb butane produces = (8*44=) 352 lb CO2

82 lb butane produces = 352*82/116 = 248.83 lb CO2

Mass of CO2 produced = 248.83 lb

Mass of H2O produced

= 18*10 lb H2O * 82 lb butane / 116 lb butane

= 127.24 lb

Mass of N2 produced

= 48.75*28 lb N2 * 82 lb butane / 116 lb butane

= 964.91 lb

For the complete combustion with stoichiometric air supplied

Mass of butane in product = 0

Mass of O2 in product = 0

Total combustion products from butane = 248.83 + 127.24 + 964.91

= 1340.98 lb

The combustion of propane with molar mass

C3H8 + 5(O2 + 3.75N2)? 3CO2 + 4H2O + 18.75N2

MM 44 32 28 44 18 28

From the stoichiometry of the reaction

44 lb propane produces = (3*44=) 132 lb CO2

212 lb propane produces = 132*212/44 = 636 lb CO2

Mass of CO2 produced = 636 lb

Mass of H2O produced

= 18*4 lb H2O * 212 lb propane / 44 lb propane

= 346.91 lb

Mass of N2 produced

= 18.75*28 lb N2 * 212 lb propane / 44 lb propane

= 2529.55 lb

For the complete combustion with stoichiometric air supplied

Mass of propane in product = 0

Mass of O2 in product = 0

Total combustion products from propane = 636 + 346.91 + 2529.55

= 3512.46 lb

Total combustion products = 1340.98 + 3512.46

= 4853.44 lb

= 4853 lb