What is the equation for the heat of formation?

The heat of formation can be found by subtracting the sum of the heats of formation for the reactants from the sum of the heats of formation of the products. The heat of formation is also referred to as the standard heat of formation or the standard enthalpy of formation.

The heat of formation is most commonly expressed in kilojoules. The equation measures the change in heat that occurs during a reaction based on 1 mole of the compound and 1 atmosphere. The reactants of a chemical equation are the components on the left side, while the products are the resulting components on the right side.