Azeotropes class 12

What is an Azeotrope

On mixing some liquids form azeotropes which are binray mixtures having same composition in liquid and vapour phase and boil at constant tempeature. In such cases the azeotropes can not be seperated into it's components by fractional distillation. There are two types of azeotropes called minimum boiling azeotrope and maximum boiling azeotrope.

Minimum boiling azeotrope

A types of solutions which show a large positive deviation fom Raoult's law from minimum boiling azeotrope at a specific composition. For example, the mixture of ethanol(C₂H₅OH)-water(H₂O) [obtained by fermentation of sugars] on fractional distillation gives a solution containing something near about 95% by volume of ethanol. once  this composition , known as azeotrope composition, has been achieved, the liquid and vapour have the same composition, and no further seperation occurs.

Maximum boiling azeotrope

The solutions that show large negative deviation from Raoult's law from maximum boiling azeotrope at a specific composition. Nitric acid and water is an example of this maximum boiling azeotrope. This azeotrope has the approximate composition of 68% nitric acid(HNO₃) and 32% water(H₂O) by mass, with a boiling point of 395.5 K.