What Is the Chemical Reaction Equation for the Combustion of Octane?

The chemical reaction equation for the combustion of octane (C8H18), which is one of the primary components of gasoline, is 2C8H18 + 25O2 —> 16CO2 + 18H2O. As the reaction equation illustrates, carbon dioxide gas is produced when octane is burned. This is typical of combustion reactions involving hydrocarbons, such as octane and propane.