What is sublimation?

Sublimation is the transition of a substance directly from the solid to the gas phase without passing through the intermediate liquid phase.

Certain solid substances like naphthalene or camphor when heated pass directly from solid to the vapour state without melting. The vapours, when cooled, give back the solid substance. This process is known as sublimation. The process is very helpful in separating a volatile solid from a non-volatile solid. The powdered substance is taken in a china dish and covered with a perforated filter paper and an inverted funnel. The dish is carefully heated on a sand bath. The vapours passing through the holes in the paper condense on the inner sides of the funnel. The non-volatile impurities remain in the dish.Sublimation is the transition of a substance directly from the solid to the gas phase without passing through the intermediate liquid phase.