Gibbs-Helmholtz equation

Encyclopedia : G : GI : GIB : Gibbs-Helmholtz equation

The Gibbs-Helmholtz equation is a thermodynamic relationship useful for calculating changes in the energy or enthalpy (heat content) of a system. It is named after Josiah Willard Gibbs and Hermann von Helmholtz. Two useful general forms of this equation are:

[\Delta A - \Delta U = T \left( \frac \right)_V]

[\Delta G - \Delta H = T \left( \frac \right)_P]

Where A is the Helmholtz free energy, U is the internal energy of the system, T is the absolute temperature, V is the volume, P is the pressure, G is the Gibbs free energy and H is the heat content(enthalpy) of the system.

From Wikipedia, the Free Encyclopedia. Original article here. Support Wikipedia by contributing or donating.
All text is available under the terms of the GNU Free Documentation License See Wikipedia Copyrights for details.