Mass Action Laws and the Gibbs Free Energy Function

Abstract : Recent progress in computational techniques for the analysis of complex chemical systems has renewed interest in the relationship between the mass action laws, which have been traditionally employed for the computation of chemical equilibrium compositions, and the Gibbs free energy function, which until recently has generally been used only for theoretical purposes. Several attendant mathematical questions, hitherto unresolved, have now become important. These concern the existence and uniqueness of a solution to the equations arising from the mass action laws; the existence and uniqueness of a composition that minimizes the free energy; and the precise relationship between the two. In Part 1, the problems are formulated, both from the mathematical and chemical viewpoints. In Part 2, mathematical tools unavailable in Gibbs' time are employed in an attempt to answer the questions posed. Some applications of the results are given in the concluding section for illustrative purposes.