A new set of composition variables for the representation of reactive-phase diagrams

A set of transformed composition variables is introduced for the representation of reactive-phase diagrams. These variables are superior to mole fractions because in the new representation, the non-reactive limits are well defined, the equilibrium surfaces are tangent at azeotropic states, and the number of linearly independent transformed composition variables coincides with the number of independent variables that describe the chemical equilibrium problem. Some examples of reactive-phase diagrams, which emphasize these features, are given.