Enthalpy

What is Enthalpy?

Enthalpy is a state function meaning In the thermodynamics of equilibrium, a state function, function of state, or point function for a thermodynamic system is a mathematical function relating several state variables or state quantities (that describes equilibrium states of the system) that depend only on the current equilibrium thermodynamic state of the system (e.g. gas, liquid, solid, crystal, or emulsion), not the path which the system has taken to reach its present state

Properties

Enthalpy is the sum of the system's internal energy and the product of its pressure and volume.

• \(H = E +PV\)
• The energy of the gas is not just the vibration. The movement of the particles kinetically also exerts a pressure.
• Using the first law: \(dh = Tds + vdp\), note specific units
• So change in specific enthalpy is change in heat plus change in pressure