A mixture of naphthalene and benzoic acid can be Separated by :

Sublimation is the process of changing a substance's state from solid to gaseous without first going through liquid when heated, and vice versa when cooled. The sublimation technique is used to separate mixtures that contain a sublimate with a volatile component from a non-sublimate contaminant. Benzoic acid is a non-volatile chemical, whereas naphthalene is a volatile substance. Because naphthalene is composed of non-polar molecules that are solely held together by Van der Waals intermolecular forces and benzoic acid is still present in the mixture, it sublimates quickly.