Question

Crystallisation is better than simple evaporation because :

• A. solid obtained after evaporation contains impurities
• B. some solids decompose on heating
• C. both A and B
• D. none of the above

Answer 1

The correct option is C both A and B

During evaporation, the liquid gets evaporated, and the solid particles are left behind. The solid obtained after evaporation has many impurities. To remove the impurities present in the solid, it is crystallized. By crystallisation, pure crystals of solid are obtained.

Another important point is evaporation requires heating, and all substances can not withstand the heat treatment. For example, the sugar solution on heating to dryness will get charred. But this problem does not arise in the case of the crystallisation method. So, crystallisation is better than evaporation.