Abstract: When species in the solution undergo multiple chemical reactions, the solution may be
treated as a solution of all species actually present or as a hypothetical solution
composed of elemental species. Based on the fundamental thermodynamic principle, the
relationships of mole numbers, molar fractions, thermodynamic properties, partial molar
properties, potential and fugacity between the hypothetical solution of elemental species
and the equilibrated solution of actual species were derived. The hypothetical elemental
solution provides a way of reducing the dimensionality of problem, simplifying the analysis
and visualizing the phase behavior.

Key words: elemental composition, dimension reduction, multireaction, phase equilibrium, thermodynamics

摘要： When species in the solution undergo multiple chemical reactions, the solution may be
treated as a solution of all species actually present or as a hypothetical solution
composed of elemental species. Based on the fundamental thermodynamic principle, the
relationships of mole numbers, molar fractions, thermodynamic properties, partial molar
properties, potential and fugacity between the hypothetical solution of elemental species
and the equilibrated solution of actual species were derived. The hypothetical elemental
solution provides a way of reducing the dimensionality of problem, simplifying the analysis
and visualizing the phase behavior.

关键词: elemental composition;dimension reduction;multireaction;phase equilibrium; thermodynamics