Question

4. (2 pts) We have seen several methods for separating mixtures of organic compounds in this course. Why are the methods of TLC, crystallization, or extraction not appropriate for separating a mixture of cyclohexane and toluene?

Answer 1

We can not use TLC, crystallization, and extraction, for the separation of mixture of cyclohexane and toluene.

Cyclohexane and toluene both are organic solvent hence they mix with each other, and they are also volatile in nature. But the difference in their boiling point is not more than 20°C , therefore they are separated by using fractional distillation.

TLC is used to separate the mixture of non volatile compound with the help of adsorbent like silica gel on the surface. As , cyclohexane and toluene both are volatile in nature , so they can not be separated by the separating process of TLC.

Crystallisation process is used where one of the component of the mixture can be precipitated by adding external chemical, or by evaporation. But this process can not be applied here because both component of the mixture are organic and can not precipitated

In extraction process, the separation of two immiscible liquid is done, but in this case cyclohexane and toluene both are miscible to each other.