Question

Given below are two statements:
Statement I: Vapours of the liquid with higher boiling point condense before vapours of the liquid with lower boiling points in fractional distillation.
Statement II: The vapours rising up in the fractionating column become richer in high boiling component of the mixture.

• A. Both Statement I and Statement II are true
• B. Both Statement I and Statement II are false
• C. Statement I is true but Statement II is false
• D. Statement I is false but Statement II is true

Answer 1

The Correct Option is C

Step 1: Analyze Statement I.
In fractional distillation, a mixture of liquids with different boiling points is heated. The liquid with the lower boiling point will vaporize first. The vapor condenses when it cools down, and since the liquid with the higher boiling point has a higher vaporization point, it condenses later. Therefore, Statement I is correct. The vapours of the liquid with a higher boiling point condense after the vapours of the liquid with a lower boiling point in fractional distillation.

Step 2: Analyze Statement II.
In a fractionating column, the vapours of the lower boiling components will rise more easily and condense at the lower parts of the column. As the vapours rise, the higher boiling components condense earlier and are left behind, making the vapour mixture become richer in the lower boiling component, not the higher boiling component. Therefore, Statement II is incorrect. The vapours rising in the fractionating column become richer in the lower boiling components, not the higher boiling ones.

Step 3: Conclusion.
Based on the analysis, Statement I is true, while Statement II is false. The process of fractional distillation involves the separation of components based on their boiling points, with the higher boiling point liquid condensing later, and the vapours becoming richer in the lower boiling component.