Question

How do you separate azeotropic mixtures?

Answer 1

1. An azeotrope is a constant-boiling mixture in which the vapour composition is the same as the liquid composition.
2. Thus by fractional distillation, the two elements can not be distinguished.
3. Fractional distillation does not separate an azeotropic mixture into its components since, when an azeotrope is boiled, the vapour has the same proportion of constituents as the unboiled mixture.
4. For low boiling azeotropes, distillation cannot fully purify the volatile component.
5. It is important to break the azeotrope which requires a method of separation that does not rely on distillation, to obtain the pure content.
6. The use of molecular sieves requires a popular technique.