Article révisé par les pairs
| Résumé : | For an assembly of N interacting particles, enclosed in a region D of space, the Helmholtz free energy per particle and the pressure, as defined by means of Gibbs configuration integral, are considered. A rigorous proof, based only on the consideration of the configuration integral, is given for the following well-known thermodynamic properties: when N is very large (more precisely tends to infinity), the free energy per particle has a finite limiting value, depending on temperature, intermolecular forces, specific volume v, but not on the shape of D: it is a continuous decreasing function of v, the derivative of which exists and defines the pressure; the pressure is a non increasing function of v. This confirms the often expressed opinion that a complete evaluation of Gibbs integral can never lead to isothermals with loops corresponding to metastable states. The assumptions made are essentially a positive incompressibility radius of the particles and intermolecular forces approaching zero rapidly enough for large separations. © 1949. |
