For the purposes of this question, we will assume that the combustion of the gasoline is complete, that is 100%. The abbreviation awu means atomic weight units. Keeping the units of measurement with each factor ensures that the correct units will appear in the answers.
step 1 convert 11.9 gallons to grams
#gal x 4Qt/gal x L/qt x ml/L x density of gasoline = grams
11.9gal x 4qt/gal x 0.94633L/qt x 1000ml/L x 0.7036g/ml = 31,694g
step 2 the chemical reaction
C8H16 + 12 O2 --> 8 CO2 + 8 H2O
step 3 the proportions - all chemical reactions are related to molecular weights, in this case, 112 awu for gasoline, 32 for oxygen, 44 for carbon dioxide, and 18
for every mole of octane, 8 moles of CO2 are produced.
so, the proportion will be (31694g x 8 x 44 awu) / 112 awu = 99,609g
step 4 convert grams to pounds
99,609g ÷ 1000g/Kg x 2.2lb/Kg = 219.1 pounds
the answer can be checked by using proportions to figure the weights of all the components.
