Calorific Value
The heat released by the complete combustion of unit mass of a fuel.
Formula / equation
CV = ΔH_c / molar mass
Unit
kJ/g
In depth
Quoted per gram rather than per mole, calorific value allows fuels of different molar masses to be compared directly. The gross value assumes the water produced condenses, while the net value does not, and the difference can exceed ten per cent for hydrogen-rich fuels.
Examples in the real world
Hydrogen delivers 142 kJ/g, petrol about 47, ethanol 30, and coal roughly 25.