CBSE Class 9 Answered
PRINCIPLE- The process of formation of crystals from a hot saturated solution from cooling.This method is based on the difference in the solubilities of solids in a liquid.
TECHNIQUE- This method in involves dissolving the mixture completely in water and heating this mixture. Further cooling of this mixture results in the formation of crystals of less soluble solid on the surface of the solution.
The mixture is added to hot water and heated in a china dish to obtain a saturated solution. The mixture is then allowed to cool till the crystals are formed.
DIAGRAM-
EXAMPLE- Preparation of pure copper sulphate crystals in the laboratory.
Purification of salt that we get from the sea.
Separation of crystals of alum from impure samples.