Simple Distillation allows for the separation of a volatile liquid from non-volatile impurities or from another liquid with a significantly different boiling point.

• Boiling Point Difference: For effective separation using simple distillation, the components of the mixture must have a boiling point difference of at least $25\text{ K}$ (or $25^{\circ }C$).
• If the boiling points are closer than this, the vapors produced will be a mixture of both components, and Fractional Distillation (using a fractionating column) must be employed to achieve purity.