Thermodynamic Properties of Very-Concentrated Electrolyte Solutions

摘要

Measured solvent vapor pressures and derived solvent activities are reported for the system LiNO sub 3 -KNO sub 3 -H sub 2 O at 373, 393, and 436 K. Mean ionic solute activity coefficients, partial molal enthalpies and enthalpies of mixing calculated using this model are tabulated. Measured vapor pressures are reported for the systems LiNO sub 3 -NH sub 4 NO sub 3 -H sub 2 O and KNO sub 3 -NH sub 4 NO sub 3 -H sub 2 O at 373 K. A single value for the ion-size parameter of the electrostatic term in the interaction model is shown to be applicable to a number of systems of the general type M/sub i/NO sub 3 -H sub 2 O. Tables of values of the nonelectrostatic interaction parameters for a number of mixed and pure nitrate solutes in water are presented. A generalized multicomponent representation of the nonelectrostatic interaction term of the model is presented and discussed. Measured solvent vapor pressures are presented for the system tetra-n-butylammonium picrate - n-butyl alcohol. Solvent activity in this system is represented, and ionic solute activities calculated, using the electrostatic-nonelectrostatic interaction model both with and without explicit consideration of a proposed ion-pairing equilibrium in this low-dielectric solvent. The ion-pairing equilibrium becomes important at higher dilution. (ERA citation 09:000920)