Question

Calculate how much carbon you use in a year, by considering how much driving you do a year. If I use 500 gal per year, what is my answer?
balanced combustion equation which shows how the main component in gasoline reacts in your car and produces carbon dioxide: 2C8H18(l) + 25O2(g) → 16CO2(g) + 18H2O(g).
Next calculate how much gasoline you use a year by estimating how many gallons you fill up in a month and then multiplying by 12. The density of octane is 2660 g/gal. Next convert the number of grams to number of moles of octane, then convert to moles of CO2 by using the balanced equation above, and then convert to grams of CO2.

Answer 1

Alex, I don't quite get it. The problem asks for how much carbon you use. Is that grams carbon. But the rest of the problem tell you to end up with grams CO2. Here is how you do it if you want grams CO2.
2660g/gal x 500 gal/year = approx 1E6 but you need to do it for a better answer.
mols gasoline = approx 1E6g/molar mass octane = approx 9000.

mols CO2 = mols octane x (16 mols CO2/2 mols octane) = approx 9000 x
8 = about 70,000.
Then grams = about 70,000 x molar mass CO2.

If you want grams C instead, multiply the above answer by 12/44. Also note that I've estimated all along so you need to start at the beginning and work your way through the entire problem.