Explain the following:
Crystallisation

Explanation

`to` This technique is used for the purification of solid organic compounds.
`to` This method is based on the difference in the solubilities of the compound and the impurities in a suitable solvent.
`to` The impure compound is dissolved in a solvent in which it is partially soluble at room temperature and appreciably soluble at higher temperature.
`to` The solution is concentrated to get a nearly saturated solution on cooling the solution pure compound crystallises.
`to` On repeating this process finally gets the very pure compound.