Question

What is the principle of crystallisation?

• A. Differences in densities of the components is used for separation.
• B. Differences in boiling point of the components is used for separation.
• C. Differences in solubilities of the components is used for separation
• D. None of these

Answer 1

Answer: (C)

Differences in solubilities of the components is used for separation

The crystallization separates the components of a mixture based on the differences in solubilities at different temperatures. The solid is dissolved in a hot solvent and then cooled. On cooling, pure crystals solidify but impurities remain in the solution and are separated from the solid. Thus in the process of cyrstallisation, densities or boiling point is not used instead, differences in solubilities are used for separation. Hence option C is correct.