Raoult's Law

Relative volatility is a comparative measure of the vapour pressures of components in a liquid mixture. It is commonly used in the design of absorption and separation processes such as distillation as it allows the difficulty of separating components to be quickly assessed.

Raoult’s law gives a method of estimating the composition and pressure of the vapour above a liquid mixture. This article describes the basis of Raoult’s law and provides an example of how to apply it.