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Helmholtz Free Energy


\LARGE F=-kT{\ln}Z



The Terms


F - Helmholtz free energy [Units: Joules, J]

k - Boltzmann constant. [Value: 1.381 x 10-23 J K-1]

T - Absolute temperature. [Units: Kelvins, K]

Z - Partition function




What it means

In statistical mechanics and thermodynamics the Helmholtz free energy is a theremodynamic potential which measures the "useful" work obtainable from a closed thermodynamic system at constant temperature, volume and particle number. For such a system in equilibrium the Helmholtz free energy is minimised.



Further information at Warwick

Helmholtz free energy is covered in the second year module "PX265 Thermal Physics II" and the third year module "PX366 Statistical Physics".

Helmholtz

Hermann von Helmholtz

1821-1894