Question

Which of the following methods would be the best for separating a mixture of butanol (b.p. 117°C) and toluene (b.p. 111°C)?

O acid-base oxtraction
O fractional distillation
O simple distillation
O recrystallization
O evaporation after dissolving in DCM

Answer 1

The correct answer is option 2. Fractional distillation is the best method to separate a mixture of butanol and toluene due to their close boiling points. Toluene, the more volatile component, would be separated first.

Step-by-step explanation:

The best method for separating a mixture of butanol (b.p. 117°C) and toluene (b.p. 111°C) is fractional distillation. Because the boiling points of the two liquids are relatively close, simple distillation might not be sufficient to effectively separate them; however, fractional distillation improves separation by allowing for multiple theoretical plates (stages of vaporization and condensation) which helps in better separation despite the close boiling points.

During the process, the more volatile component, in this case toluene, would vaporize first and would be collected prior to butanol. The diagram for the Distillation of Petroleum illustrates a similar process where components with lower boiling points condense at the top of a distillation column, while those with higher boiling points condense at the bottom. This principle is applicable to the separation of butanol and toluene using a fractional distillation apparatus.