Combustion reactions

When a substance that is made up of:

• carbon and hydrogen, or

 examples: methane, CH4; ethane, C2H6; propane, C3H8;

• carbon, hydrogen and oxygen

 examples: methyl alcohol, CH3OH; ethyl alcohol, C2H5OH; propyl alcohol, C3H7OH;

undergoes complete combustion (ie - burning with oxygen gas), the products of the reaction are carbon dioxide gas, CO₂, and water, H₂O.

Examples

1. Combustion of octane, C₈H₁₈, a substance that is present in gasoline.

2 C₈H₁₈ (l) + 25 O₂ (g) 2 CO₂ (g) + 3 H₂O (l)

2. Combustion of propyl alcohol, CH₃CH₂CH₂OH, yields carbon dioxide and water.

2 CH₃CH₂CH₂OH(l) + 9 O₂ (g) 6 CO₂ (g) + 8 H₂O (l)