— Enthalpy change
The change in enthalpy of a system at constant pressure, equal to the heat absorbed or released by the reaction. ΔH < 0 means the reaction releases heat (exothermic); ΔH > 0 means it absorbs heat (endothermic). Standard enthalpy changes (ΔH°) are tabulated per mole of reaction as written.
SI unit: kJ/mol
Used in
- Hess's law
- Calorimetry
- Bond enthalpies