Gasoline is a remarkably interesting soup of hydrocarbons of various sorts, with bits of this and that added, but the average chemistry is not too far from being carbon and hydrogen, with two hydrogen atoms for each carbon. Burning involves combining gasoline with oxygen to make water and carbon dioxide. (Other things that are made in small quantities, such as carbon monoxide, are not as nice.) The chemical formula for burning gasoline can then be written something like: CH2+1.5 O2 --> CO2+H2O (If you don’t like having one-and-a-half oxygen molecules, you can think of two hydrocarbons plus three oxygens making two carbon dioxides and two waters; it is the same thing, really.) In burning, each carbon atom, C, in gasoline eliminates two hydrogens and replaces them with two oxygens each carbon atom weighs 12 atomic mass units each hydrogen weighs 1 each oxygen weighs 16; So, CH2 starts out weighing 14 (12 from carbon and 2 from hydrogen), and CO2 ends up weighing 44 (12 from carbon and 32 from oxygen)—the weight has more than tripled. Rounding that off a little, the total weight of CO2 put out by a typical U. S. driver is three times larger than the weight of gasoline burned. To get the number of pounds of CO2 per year from a typical car, then, multiply your answer from the previous question by 3.