Which of the following units is commonly used to express the heat of combustion?

Heat of combustion measures the energy released when one mole of a substance burns completely. Scientists express this as joules per mole to show energy per unit amount of substance.

Joules measure energy, and moles measure amount of substance. Combining these as J/mol allows comparison of energy release from different fuels.

Kilojoules per mole (kJ/mol) is also common since combustion releases large amounts of energy. This unit helps chemists calculate how much fuel is needed for specific energy requirements.