The recently proposed model [Geochim. Cosmochim. Acta 64 (2000) 495; Geochim. Cosmochim. Acta 64 (2000) 2779] for correlating the infinite dilution partial molar properties of aqueous nonelectrolytes is briefly outlined. The approach is fundamentally based on the A12 = V2 0/κRT parameter, related to the infinite dilute solute-water direct correlation function integral. The A12 parameter is considered as a semiempirical function of temperature and density. At supercritical temperatures thermodynamic integrations of this function allow calculation of all thermodynamic functions of hydration (V2 0, ΔhG0, ΔhH0 and ΔhCp 0) of a solute. An extension to subcritical conditions is done using an auxiliary ΔhCp 0(T, Pr)-function, which describes the temperature course of the heat capacity of hydration of a solute at Pr = 28 MPa and subcritical temperatures. The variations of the ΔhCp 0(T, Pr)-function are constrained by known values of ΔhG0, ΔhH0 and ΔhCp 0 at ambient and supercritical conditions. This model, which was used earlier to correlate properties of a few dissolved gases, is successfully employed here to describe V2 0, ΔhG0, ΔhH0 and ΔhCp 0 experimental results for a number of aqueous nonelectrolytes, including ones of high polarity (alcohols, amines, acids and amides) and/or large size (hexane and benzene).
- Chemical potential
- Equation of state
- Gibbs energy
- Heat capacity
ASJC Scopus subject areas
- Fluid Flow and Transfer Processes
- Physical and Theoretical Chemistry