Enthalpy is a thermodynamic quantity that describes the heat content of a system, that can not be measured directly. That's why we measure change in enthaply, measured in the units joules. The statement that enthalpy change depends on the rate at which a substance is heated or cooled is false. Enthalpy change depends only on the following factors:
-physical state of reactants and products
- quantity of reactants
- allotropic modifications
- temperature and pressure