Explain the sublimation technique used for the purification of organic compounds.

(N/A) Definition: On heating,some solid substances change directly from the solid state to the vapour state without passing through the liquid state. The purification technique based on this principle is known as sublimation.
Uses: It is used to separate sublimable compounds from non-sublimable impurities.
Examples: The sublimation technique is used for the purification of a mixture of $CaSO_4$ and camphor. Camphor undergoes sublimation and is separated,while $CaSO_4$ remains at the bottom as it does not sublime.