A website promoting the use of alternative energy vehicles and hybrid technologies claims that, “A typical automobile in the USA uses about 250 gallons of gasoline every six months, producing about 2.5 tons of carbon dioxide.” To determine the truth of this statement, calculate how many tons of carbon dioxide are produced when 250.0 gallons of gasoline are combusted. Assume that the primary ingredient in gasoline is octane, C8H18(l), which has a density of 0.703 g·mL–1..
1 Answer

balanced equation..
.. 2 C8H18 + 25 O2 —> 16 CO2 + 18 H2O
then.. converting
250.0gal gas x (3.7854L / gal) x (1000mL / 1L) x (0.703g / mL) x (1 mol gas / 114.23g gas) x (16 mol CO2 / 2 mol gas) x (44.011g CO2 / mol CO2) x (1lb / 453.59g) x (1ton / 2000lb) = 2.26ton CO2