Question

The mixture that forms maximum boiling azeotrope is ______.

Options

• ethanol + water

• acetone + carbon disulphide

• heptane + octane

• water + nitric acid

Answer 1

The mixture that forms maximum boiling azeotrope is water + nitric acid.

Explanation:

Azeotropes are mixtures that boil at a constant temperature and retain the same composition in vapour and liquid phases. A maximum boiling azeotrope occurs when the mixture shows negative deviation from Raoult’s law (stronger A-B interactions). Water and nitric acid form a maximum boiling azeotrope at about 68% HNO₃ and boil at 121°C, which is higher than both pure components.