Rationale

The heat released by the complete combustion of materials is an important quantity in choosing fuels for heating, power generation and propulsion. The combustion reaction is the foundation of technological societies, and the efficient use of fuel is essential to reduce atmospheric pollutants such as CO₂ and to conserve finite fuel resources, particularly those suitable for mobile power plants. When carbon is burned in an adequate supply of oxygen, the reaction may go to completion and can be described by the overall reaction equation: C + O₂ Þ CO₂ . If the reaction does not go to completion, CO (carbon monoxide) will be one of the combustion products in addition to the carbon dioxide. If either the total quantity of oxygen or the rate at which oxygen and carbon can reach each other during the reaction is low enough, some un-reacted carbon can remain. The total heat released during the exothermic combustion reaction will depend upon the reactants and the final reaction products.

If the reaction takes place at constant volume, no external work is done and the First Law shows that the energy liberated, the heat of combustion, may be written in terms of the