JEE Main · 2025 · 08 Apr 2025 · Shift 2 · Solutions

A minimum boiling azeotrope arises from positive deviation from Raoult's law, where unlike molecules attract one another less strongly than like molecules do. Water with ethyl methyl ketone, carbon disulphide with acetone, and methanol with chloroform all show positive deviation and so form minimum boiling azeotropes. Phenol and aniline, by contrast, attract each other strongly through hydrogen bonding between the acidic phenol and the basic amine, producing negative deviation and a maximum boiling azeotrope. The mixture of phenol and aniline therefore does not show minimum boiling azeotropic behaviour.