Final answer:
Simple distillation is commonly employed in the separation of mixtures of liquids with different boiling points. It is used in the refining of crude petroleum and the distillation of alcoholic spirits.
Step-by-step explanation:
Simple distillation is commonly employed in circumstances where mixtures of two or more liquids with different boiling points need to be separated. For example, simple distillation is used in the refining of crude petroleum to separate it into different products such as aviation fuel, gasoline, kerosene, diesel fuel, and lubricating oil. Another common use of simple distillation is in the distillation of alcoholic spirits like brandy or whiskey.