Fractional Distillation: Principle: This method is used for the separation of a mixture containing two miscible liquids, for which the difference in their boiling points is less than 25o C.Technique: The mixture is kept in a distillation flask attached with a fractionating column, having glass beads. The flask is then carefully heated. The mixture first evaporates and later condenses. The glass beads present in the fractional column provide a larger surface area for the vapours to cool down. This technique is used to separate mixtures made up of two miscible liquids with a difference in their boiling points less than 25oC.