Question

List two properties of the mixture of miscible liquids essential for the process.

Answer 1

Distillation is used for separating a liquid mixture into its components, when both the components are miscible with each other and the difference in the boiling points of the liquid components is more than 20-25 degree celsius. The mixture is heated in a flask until the mixture boils, the vapours produced due to boiling of liquid are passed through a condenser, where they are condensed back to the pure liquid which is collected separately

Answer 2

(i) The separation technique depends upon the boiling temperature difference between the miscible liquids. If they differ in their boiling points by

or more, the separation can be done by simple distillation. If the difference is less than

, fractional distillation is used. Acetone (b.p. =

) and water (b.p. =

) can be separated by simple distillation. <br> (ii) The constituents of the miscible liquids should be volatile in nature. <br> The constituents of the miscible liquids should not react chemically with each other. <br> (iii) The purpose of beads in the fractionating column is to obstruct the upward movement of liquid with higher boiling point. This helps in the separation of the two liquids.