Thermodynamic Equilibria and Extrema
Since the creation of classical equilibrium thermodynamics in the second part of the nineteenth century by Clausius, Helmholtz, Maxwell, Gibbs, and Bolzmann, its potential has increased immeasurably due to the rapid development of numerical mathematics and computers. Now models based on Gibbs's fundamental equations allow one not only to find the point of final equilibrium in a given system, but also to examine the entire area thermodynamically attainable from a given initial point. Moreover, they are capable of finding in this area the equilibrium states (partial equilibria) of interest to a researcher for their extreme values of a considered parameter such as the concentration of useful or harmful products of a chemical process. In doing so, it appears possible to take into consideration in a strict thermodynamic form (with no use of the time variable) the limitations posed by chemical reaction rates and irreversible processes of mass, energy, and impulse transfer.