1 Matching Results

Search Results

Advanced search parameters have been applied.

Ion-association: Models and thermodynamics

Description: Association reactions are an important class for probing ion-water and water-water interactions. A review of some earlier results led to a model of ion-association reactions discussed by Mesmer et al. in Activity Coefficients of Electrolyte Solutions in 1991. Additional results especially from electrical conductance studies on acids and salts will be discussed. There is mounting evidence consistent with the general observations regarding the temperature and pressure dependencies for thermodynamic quantities for association reactions seen earlier including the driving force, T{Delta}S, that originates from the release of ion hydrate waters when pairing occurs. The density model for log K{sub A} serves well as a simple representation of the strong variation with temperature and pressure seen for these reactions. The decrease in solvent structure with increasing temperature and the increasing range of the ion-dipole interactions for hydrated ions (with decreasing dielectric constant) are thought to be the principal factors accounting for the dramatic trends seen for the thermodynamic quantities. Some discussion will be given of the simplicity found for the T-P dependencies for {delta}U{sub v} and {delta}C{sub v}, the changes in internal energy and heat capacity on a constant volume basis.
Date: July 1, 1995
Creator: Mesmer, R.E.; Ho, P.C.; Holmes, H.F.; Palmer, D.A. & Simonson, J.M.
Partner: UNT Libraries Government Documents Department