Introductory Chemical Engineering Thermodynamics

Chapter 11. An Introduction to Activity Models

First, do no harm.

Hippocrates

The subject of non-ideal solutions includes just about everything from aqueous acids to polymers to semiconductors. Not surprisingly, there is no completely general model for non-ideal solutions. But there are several popular approaches for specific situations like VLE of alcohols or LLE of organic solvents with water. We discuss typical models and briefly explain their forms and history. Moreover, the challenge of developing accurate descriptions of non-ideal solution behavior means that model development is still an active research area. The presentation here should provide enough background to understand the rationales behind new developments as well as the old. ...