1.   From our point of view the most important types of physical equilibria are phase equilibria --that is, the equilibria that exist between the phases of a system.

2.   The dynamic nature of phase equilibria can be understood by considering them in the light of the kinetic theory.

3.   Experimental data on the influence of temperature and pressure on phase equilibria can be represented by phase diagrams.

4.   In this section we shall be examining phase equilibria of some heterogeneous mixtures.

5.   However, we shall be principally interested in phase equilibria involving homogeneous mixtures-that is solutions.