17.1 - Phase equilibria

17.1.1 State and explain the equilibrium established between a liquid and its own vapour. Liquid- vapour equilibrium is a dynamic equilibrium established when the rate of condensation equals the rate of vaporisation. The vapour pressure is independent of the volume of the container, liquid or vapour.

17.1.2 State and explain the qualitative relationship between vapour pressure and temperature.
Students should be able to show the relationship graphically and explain it in terms of kinetic theory

When Kc >> 1, the reaction goes almost to completion.
When Kc << 1, the reaction hardly proceeds.

17.1.3 State and explain the relationship between enthalpy of vaporisation, boiling point and intermolecular forces

Students should be able to predict the relative strength of the intermolecular forces of different liquids when given the physical properties or vice versa. Cross reference with 4.3

Useful links