Main Page | See live article | Alphabetical index

Standard enthalpy change of reaction

The standard enthalpy change of reaction is the enthalpy change that occurs in a system when 1 equivalent of matter is transformed by a chemical reaction under standard conditions.

For a generic chemical reaction

nA A + nB B + ... → nP P + nQ Q ...

the standard enthalpy change of reaction ΔHr is related with the standard enthalpy change of formation ΔHf of the reactants and products by the equation