How much CO2 is produced by the combustion of 1 gal of gasoline?

Answer 1

Figure the weight of the gasoline, and since each carbon atom ties to 2 oxygen, figure on 3 times the gasoline weight (approximate).
So roughly about 24 pounds.

Answer 2

Taking gasoline as n-octane, C8H18, density 5.9lb/gal, the balanced equation is:

C8H18 + 17O2 ===> 8CO2 + 9O2

Let gasoline be called G
Atomic weights: C=12 H=1 O=16 C8H18=114 CO2=44

1galG x 5.9 lbG/1galG x 1 lb-molG/114 lbG x 8 lb-molCO2/1 lb-molC8H18 x 44 lbCO2/1 lb-molCO2 = (5.9)(8)(44)/(114) = 18.2 lbCO2

Just as there is 44g CO2 in a gram-molecular weigtht, so there are 44 lb CO2 in a "pound-mole." Atomic and molecular weights are relative.

For the future, it might be good to memorize the density of water, 8.320 lb/gal. If you have the density of another liquid in g/mL, that's the same asspecific gravity, and multiplying the specific gravity by 8.320 gives density of the other liquid in lb/gal.

Answer 3

According to this website
http://www.epa.gov/otaq/climate/420f05001.htm
1 gal of gas has 2,421 grams of carbon, which is roughly 2500 grams
The ratio of mass of CO2/C is

(12+2*16)/12=44/12=11/3

which is roughly 4

2500*4=10,000

So we get roughly 10 kg of CO2 from 1 gallon of gas.