Question

​In the reaction where cyclohexanol is put into a round bottomflask with phosphoric acid and sulfuric acid and heated in a fractional distillation system, why is it important to use a round bottom flask that fits tightly onto the distillation apparatus as th reciever. Why is it then cooled in an ice bath?

Answer 1

In this reaction cyclohexene from cyclohexanol using phosphoric acid and an sulfuric acid catalyzed reaction.

inthe reactionn system water will produce, if water and sulfiric acid is there , then it will be again reversible reaction.so phosphoric acid work as dehydrating agent.after reaction will do distillation to get pure product.

Fractional distillation is the method separation of a mixture into its component parts, or fractions, separating chemical compounds by its boiling point by heating them to a temperature at which one or more fractions of the compound will vaporize. It uses distillation to fractionate,it is important to use round bottom flask and that tightly fits onthe distillation apparatus as the reciever. because when heat the distllation flask of round bottom flask stir bar rotate in center of round bottom flask, it cannot touch corners, this is the only option for small scale synthesis (below Kg level).and the other it shouldbe tightly fit on heat system, when heating system if leak is there the vapours can cool, then it can not possible distillaton, once it pass to condenser then cooling required(receiver), if not cooled we will lose some prouct in its vaour, so when it cool the vapour then it will come naromal temperature as liquid.