Enthalpy is a defined thermodynamic potential, that consists of the internal energy of the system (U) plus the product of pressure (p) and volume (V) of the system. Enthalpy is a measure of the total energy of a thermodynamic system. It includes the internal energy, which is the energy required to create a system, and the amount of energy required to make room for it by displacing its environment and establishing its volume and pressure. Enthalpy is a state function. ( State function or state variable is a property of a system that depends only on the current state of the system, not on the way in which the system acquired that state. A state function describes the equilibrium state of a system ). Enthalpy change accounts for energy transferred to the environment at constant pressure through expansion or heating.

Related formulas


His the enthalpy of the system (J)
Uis the internal energy of the system (J)
pis the pressure of the system (Pa)
Vis the volume of the system (m3)