Enthalpy: Enthalpy (H) is defined so that changes in enthalpy (deltah) are equal to the heat absorbed or released by a process running at constant pressure. While changes in enthalpy can be measured using calorimetry, absolute values of enthalpy usually cannot be determined. Enthalpy is formally defined as H = U + PV, where U is the internal energy, P is the pressure, and V is the volume.

 

Related Words

Enthalpy: Enthalpy (H) is defined so that changes in enthalpy (deltah) are equal to the heat absorbed or released by a process running at constant pressure. While changes in enthalpy can be measured u . . . View Full Definition

Enthalpy Of Sublimation: The change in enthalpy when one mole of solid vaporizes to form one mole of gas. Enthalpies of sublimation are always positive because vaporization involves overcoming most of the intermolec . . . View Full Definition

Average Bond Enthalpy: Average enthalpy change per mole when the same type of bond is broken in the gas phase for many similar substances.

Standard Enthalpy Change: A change in enthalpy associated with a reaction or transformation involving substances in their standard states.