Document Type


Date of Award

Spring 1-31-1991

Degree Name

Doctor of Philosophy in Chemical Engineering - (Ph.D.)


Chemical Engineering, Chemistry and Environmental Science

First Advisor

Dana E. Knox

Second Advisor

Ernest N. Bart

Third Advisor

Richard Clyde Parker

Fourth Advisor

R. P. T. Tomkins

Fifth Advisor

Ralph D. Gray


Thermodynamic properties (osmotic coefficients) of strong electrolyte solutions have been studied by the method of statistical mechanics. First the charged soft sphere potential is developed based on the Pauling type model. Next the charged soft sphere potential is converted to the thermodynamically corresponding charged hard sphere potential by way of the perturbation method developed by Verlet and Weis. Simultaneously, the radial distribution function is developed by modification of the Exponential theory through introduction of the Stillinger-Lovett moment condition. The effective hard sphere diameter values calculated by the perturbation method are combined with the modified Exponential theory, and these quantities are integrated to get the osmotic coefficients. These procedures are applied to 28 single electrolyte solutions. They are 1-1, 1-2, and 2-2 type strong electrolyte solutions. The calculated results are compared with Pitzer's model. Generally, the new model gives better results than Pitzer's. This model shows excellent results at low concentrations, as well as at higher concentrations up to the limitation of the experimental data in most of the cases.