(i) What is the principle for using fractional distillation as a separation technique? (ii) Explain the function of a simple fractionating column in a fractional distillation method of separation. (iii) Suggest one application of this technique.
Answers
Answer:
The basic principle of this type of distillation is that different liquids boil and evaporate at different temperatures. So when the mixture is heated, the substance with lower boiling point starts to boil first and convert into vapours.
1. The principle of fractional distillation is that different liquids boil at different temperature. The miscible liquids boil at different temperature and evaporate at different temperature. When the mixture is heated, the liquid with lower boiling point boils and turns into vapours.
2.Fractionating columns help to separate the mixture by allowing the mixed vapors to cool, condense, and vaporize again in accordance with Raoult's law. With each condensation-vaporization cycle, the vapors are enriched in a certain component. A larger surface area allows more cycles, improving separation.
3.Separation of miscible liquids by fractional distillation It helps to obstruct the upward movement of the vapours of the two liquids.