Abstract
A semitheoretical approach for the ionization constant of water, K W, is used to fit the available experimental data over wide ranges of density and temperature. Statistical thermodynamics is employed to formulate a number of contributions to the standard state chemical potential of the ionic hydration process. A sorption model is developed for calculating the inner-shell term, which accounts for the ion-water interactions in the immediate ion vicinity. A new analytical expression is derived using the Bragg-Williams approximation that reproduces the dependence of a mean ion solvation number on the solvent chemical potential. The proposed model was found to be correct at the zero-density limit. The final formulation has a simple analytical form, includes seven adjustable parameters, and provides good fitting of the collected KW data, within experimental uncertainties, for a temperature range of 0-800°C and densities of 0-1.2 g cm-3.
Original language | English (US) |
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Pages (from-to) | 15-30 |
Number of pages | 16 |
Journal | Journal of Physical and Chemical Reference Data |
Volume | 35 |
Issue number | 1 |
DOIs | |
State | Published - 2006 |
All Science Journal Classification (ASJC) codes
- General Chemistry
- General Physics and Astronomy
- Physical and Theoretical Chemistry