ABSTRACT
At high enough temperature and low enough pressure the interactions among the atoms or molecules in mixtures of gases are small enough that they can be neglected, in which case the mixture can be considered to be a mixture of ideal gases. Consequently, at high temperature and low pressure, all mixtures of gases have the same thermodynamic mixing properties. In contrast, strong interactions exist between atoms, molecules, or ions in condensed solutions, and the nature and magnitudes of these interactions have a significant influence on the thermodynamic behavior of the solution. The interactions, which are determined by such factors as atomic size, electronegativity, and electron-to-atom ratio, determine the extent to which a component is soluble in a solution and whether or not two or more components can react chemically to form a separate species. Solution thermodynamics is concerned with the vapor pressure-temperature-composition relationships of the components of a solution, and an examination of solution thermodynamics is made in the chapter.
