Which method of distillation is used to separate liquids with similar boiling points?

The correct method to separate liquids with similar boiling points is fractional distillation. This technique is specifically designed for the separation of components in a mixture that have closely related boiling points, often within a few degrees of each other.

Fractional distillation employs a fractionating column, which provides a large surface area for multiple condensation and vaporization cycles to occur as the mixture is heated. This column allows for the repeated separation of the liquid components based on their volatility, leading to the purification of each liquid as it passes through the column. As the mixture heats, the component with the lower boiling point vaporizes first and is collected, while higher boiling components are repeatedly condensed and re-vaporized until they can be separated effectively.

In comparison, while simple distillation is suitable for separating components with significantly different boiling points, it lacks the efficiency and effectiveness needed for closely boiling liquids.

Vacuum distillation is utilized to separate compounds with very high boiling points or to avoid thermal decomposition by reducing the pressure. Steam distillation is primarily used for extracting volatile compounds from non-volatile ones, such as essential oils from plant materials, rather than separating liquids with similar boiling points. Therefore, in the context of separating liquids that are closely related in boiling point, fractional dist