Question

Both simple distillation and fractional distillation can be used to separate two miscible liquids present in a mixture. If they differ in boiling points by more than${25}^{\circ }$$C$, simple distillation is used. In case the difference is less than this temperature, then the process of fractional distillation can be employed. A fractionating column is used in the case of fractional distillation and is placed in the distillation flask. It can have a variety of shapes. No such column is needed in the case of simple distillation.

1. Which distillation process can be used to separate a miscible liquid mixture of acetone (bp = 56$°$C) and ethyl alcohol (bp = 78$°$C)?
2. How does fractionating column work in this case?
3. Which liquid will get distilled first?
4. What will happen if the fractionating column is removed?

Answer 1

1. Process of fractional distillation is used to separate a miscible liquid mixture of acetone (bp = 56$°$C) and ethyl alcohol (bp = 78$°$C). Fractional distillation is used in separating liquids having boiling points close to one another. In fractional distillation, the experimental setup is complex consisting of complex apparatus and a fractionating column.
2. The upward movement of high boiling liquid is obstructed by fractionating column. When its vapor condenses, the energy released is taken up by low boiling liquid vapors which readily move upward.
3. The liquid with a low boiling point will distill first. In the given question acetone will distill first.
4. The fractionating column provides a surface area for the liquid vapors to condense very fast. If the fractionating column is removed both acetone and ethyl alcohol vapors will get distilled simultaneously.