Distillation

Distillation as a family of techniques purifies LIQUIDS -- either by separating a liquid from a non-volatile impurity, or by separating the individual components of a liquid MIXTURE whose components differ in boiling point -- and covers simple distillation, fractional distillation and steam distillation. In simple distillation, the impure liquid is simply boiled, the vapour given off is collected and led away, and that vapour is condensed back into pure liquid in a separate receiver; this straightforward approach works well specifically when the components of a mixture have boiling points that differ by a wide margin (roughly 40 K or more) and neither one decomposes at ordinary atmospheric pressure -- illustrated in the text by a nitrobenzene (boiling point 484 K) and benzene (354 K) mixture, and by a diethyl ether (308 K) and ethyl alcohol (351 K) mixture, both pairs separable cleanly by plain simple distillation. …