The process of purifying a substance by boiling it and then condensing the resulting vapor is called distillation. This process is widely used in the laboratory and in industry to separate and purify liquids and gases.

The principle behind distillation is that different substances have different boiling points. The boiling point of a substance is the temperature at which the substance converts from a liquid to a gas. When a mixture of liquids is heated, the liquid with the lowest boiling point will vaporize first. The vapor can then be condensed back into a liquid, and the process can be repeated to further purify the substance.

Distillation can be carried out using a variety of apparatus, including simple stills, fractionating columns, and rotary evaporators. The type of apparatus used will depend on the specific application and the desired level of purity.

Distillation is a powerful tool for purifying substances, and it is used in a wide variety of industries, including the food, beverage, pharmaceutical, and chemical industries.