Modification of the phase rule for optical enantiomers and other symmetric systems

Abstract

In symmetric binary and multicomponent systems where two pure components have identical thermodynamic properties (e.g., in mixtures of D- and L-optical enantiomers), the usual equation for the Gibbs phase rule must be modified. For example, in symmetric binary systems, as many as six phases may coexist at a particular temperature and pressure and tricritical points are possible.