Components of a binary mixture of two liquids A and B were being separated by distillation. After some time separation of components stopped and composition of vapour phase became same as that of liquid phase. Both the components started coming in the distillate. Explain why this happened.

Question

Components of a binary mixture of two liquids A and B were being separated by distillation. After some time separation of components stopped and composition of vapour phase became same as that of liquid phase. Both the components started coming in the distillate. Explain why this happened.

Philoid · Accepted Answer

Both the components start coming to distillate as they would have formed an azeotropic mixture. Azeotropes are the binary mixtures having the same composition in liquid and vapor phase and boil at constant temperature. So it is not possible to separate them by distillation.