Date of Award


Degree Name

Master of Science



First Advisor

Dr. Donald R. Schreiber

Second Advisor

Dr. John Miller

Third Advisor

Dr. Subra Muralidharan

Access Setting

Masters Thesis-Open Access


Pitzer's Ion-interaction Model had been widely used in predicting the non-ideal behavior of solution over a wide range of conditions for natural water systems. The model is successful only when there are sufficient parameters available. However, generating these needed parameters requires a great quantity of work and it would be advantageous to be able to predict the Pitzer's parameters for salt systems when there is no data available.

This research entailed the development of ionic radii dependent equations for Pitzer's binary ion-interaction parameters βMX(0), βMX(1), βMX(2), and CϕMX . Experimental data of the activity coefficients of binary electrolytes were gathered and the modified Pitzer equations were then fit to the data, using nonlinear regression. Equations for all salts of a particular charge type and salts of a particular anion with cations of similar charge were developed. The values of these equations were tested and shown that they could be used in the absence of experimentally determined parameters. The concept of ionic radii dependency was extended to temperature dependent equation (e.g. heat of dilution).

Included in

Chemistry Commons