The amount of CO2 produce from burning a single gallon of gasoline.

1. Chemistry in Context
Oil Combustion and its contribution to CO2 emissions

2. Combustion Reaction
Combustion reaction - is a sequence of
exothermic reactions in which a substance reacts
with oxygen, usually with the rapid release of heat
to produce a flame
The products include one or more oxides
Organic compounds usually burn in oxygen to yield
carbon dioxide
2C4H10(g) + 13O2(g) 8CO2(g) + 10H2O

3. Carbon Emissions
How much CO2 does one gallon of gasoline produce?

4. Carbon Emissions
An 87-octane gasoline, is 87% (by volume)
iso-octane (2,2,4-Trimethylpentane) and
13% n-heptane
C8H18
C7H16

5. Emission Calculations
1 US Gallon
3.785 L
1 US Gallon
X = 3.785 L of gasoline
3.785 L of gasoline
0.87 Iso-octane
1 L gasoline
X = 3.29 L
Iso-octane
3.785 L of gasoline
0.13 n-heptane
1 L gasoline
X = 0.49 L
n-heptane

6. Carbon Emissions
3.29 L of iso-octane
688 g
1 L
X = 2,260 g iso-octane
0.49 L n-heptane
684 g
1 L
X = 335 g n-heptane
Hydrocarbon Density Molarity
C8H18 0.688 g/ml 114.22 g/mol
C7H16 0.684 g/ml 100.21 g/mol
CO2 1.98 g/L 44.01 g/mol

7. Carbon Emissions
2,260 g iso-octane
1 mole
114.22 g
X = 19.78 moles
iso-octane
335 g n-heptane
1 mole
100.21 g
X = 3.34 moles
n-heptane
Hydrocarbon Density Molarity
C8H18 0.688 g/ml 114.22 g/mol
C7H16 0.684 g/ml 100.21 g/mol
CO2 1.98 g/L 44.01 g/mol

8. Carbon Emissions
iso-octane combustion reaction:
C8H18 + 12.5O2(g) 8CO2(g) + 9H2O(g)
19.78 moles
iso-octane = 158.24 moles CO2
C7H16 + 11O2(g) 7CO2(g) + 8H2O(g)
= 23.38 moles CO2
3.34 moles
n-heptane
158.24 moles CO2
+23.38 moles CO2
181.62 moles CO2

9. Carbon Emissions
181.62 moles CO2
44.01 g
1 mole
X = 7,993 g CO2
0.002204 lbs
7,993 g CO2 =
1 g
17.61 lbs CO2
Per gallon
of gasoline
Hydrocarbon Density Molarity
C8H18 0.688 g/ml 114.22 g/mol
C7H16 0.684 g/ml 100.21 g/mol
CO2 1.98 g/L 44.01 g/mol

10. Carbon Emissions
2,595 g of Gasoline
0.002204 lbs
1 g
= 5.7 lbs/gallon
Mass of Gasoline:
Mass of Carbon dioxide: 17.61 lbs CO2/gallon

11. “IF SOMEONE SAYS: “THAT’S IMPOSSIBLE” YOU SHOULD
UNDERSTAND IT AS: “ACCORDING TO MY LIMITED EXPERIENCE
AND NARROW UNDERSTANDING OF REALITY, THAT’S VERY
UNLIKELY"