THE HONIG-FLORY-HUGGINS COMBINATORIAL ENTROPY CORRECTION - IS IT VALID FOR AQUEOUS-SOLUTIONS

A number of assumptions used in the derivation of the combinatorial en tropy term of Honig-Flory-Huggins are shown not to be valid for the ca se of dilute solutions in water: these include (a) only combinatorial entropy need be considered. (b) the solution configuration is random, and (c) random distribution of molecular segments in the solution latt ice. Accordingly, the combinatorial term as calculated by Honig-Flory- Huggins is not appropriate for aqueous solutions, and is particularly inappropriate for dilute solutions in water. It is suggested that the use of the Honig-Flory-Huggins combinatorial entropy term to 'correct' observed thermodynamic parameters for solvation of solutes in water b e abandoned.