# Helmholtz Free Energy

### The Terms

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

- Boltzmann constant. **[Value: 1.381 x 10 ^{-23} J K^{-1}**

**]**

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

### 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".