Question

Organic Chemistry Lab: Distillation.

a.) In vacuum distillation, how you do ensure that the liquid does not boil too suddenly upon reduction of pressure?

b.) When carrying out a fractional distillation,

i.) What is the ideal boiling point difference for the two components of the mixture you are distilling?

ii.) what needs to be adjusted if the boiling point difference is smaller than above?

Answer 1

a) in Vacuum distillation, reducing the pressure and taking care that it does not go below its vapour pressure we can be sure that the liquid does not boil too suddenly.

b)i) Generally the component parts have boiling points that differ by less than 25 °C from each other under a pressure of one atmosphere. If the difference in boiling points is greater than 25 °C, a simple distillation is typically used.

ii) for this, we have to increase the number of chambers in the distillation setup