When is simple distillation useful for purifying a liquid?

Simple distillation is a fundamental laboratory and industrial technique used to purify liquids based on differences in their boiling points. It is particularly useful in two primary scenarios:12

• Separating liquids from nonvolatile solids: This process effectively isolates a liquid from impurities that do not vaporize, such as separating alcoholic liquors from fermented materials.1
• Separating liquids with widely divergent boiling points: Simple distillation is reasonably adequate for mixtures where the components have significantly different boiling points, allowing the most volatile substance to vaporize and condense first.1

In this process, a mixture is heated in a still or retort, and the resulting vapor is cooled in a condenser before being collected as a purified liquid. While highly effective for these specific purposes, simple distillation is generally not efficient for separating liquids with boiling points that are close together; in such cases, fractional distillation is required to achieve a sharper separation.12