Question

How can we separate sugar from its sugar solution?
(A) Evaporation
(B) Crystallization
(C) Filtration
(D) Decantation

Answer 1

Hint: The sugar solution is formed by dissolving sugar in water. All the methods, evaporation, crystallization, filtration and decantation are the physical methods of separation.


Step by step answer: The process in which any substance in a liquid state is converted to its gaseous state is known as evaporation.
When a sugar solution is evaporated the water in the solution will evaporate leaving behind sugar crystals. Bur the sugar obtained by evaporation is charred. Charred sugar means some hydrogen and oxygen atoms from the sugar molecule can be lost.
Thus, we cannot separate sugar from its solution by evaporation.
Thus, option (A) is not correct.
The process in which hot solutions are allowed to cool down naturally to obtain crystals of the solute in pure form is known as crystallization.
When a sugar solution is heated and allowed to cool down naturally, we can see the crystals of sugar forming in the solution. These crystals are free of any impurities.
Thus, we can separate sugar from its solution by crystallization.
Thus, option (B) is correct.
The process in which the undissolved solids can be separated or removed from the solution is known as filtration.
Sugar completely dissolves in water. Thus, the sugar solution does not have undissolved sugar.
Thus, we cannot separate sugar from its solution by filtration.
Thus, option (C) is not correct.
The process of separating a solid from a liquid when the solid is immiscible in liquid by allowing the mixture to stand for some time and then removing the top liquid layer is known as decantation.
Sugar completely dissolves in water. Thus, the sugar solution does not have undissolved sugar.
Thus, we cannot separate sugar from its solution by decantation.

Thus, option (D) is not correct.


Note: Remember during evaporation, pure crystals of sugar cannot be obtained. Thus, crystallization is preferred over evaporation.