Introductory Chemical Engineering Thermodynamics

Chapter 18. Electrolyte Solutions

Water, water, every where, Nor any drop to drink.

S.T. Coleridge, “The Rime of the Ancient Mariner”

Electrolyte solutions are as common as seawater. They exist in every biological organism, in underground reservoirs, and in numerous industrial processes. Thermodynamic models of electrolyte solutions can range from extremely simple to extremely complex. At the simple end of the spectrum are solubility product constants, familiar from introductory chemistry courses. At the complex end of the spectrum, we recognize that concentrated solutions can lead to ion-ion interactions that influence the activity coefficients, altering the simultaneous reaction and phase equilibria that pervade the entire subject. Our goal ...