Q10 / 180 · COMEDK 2022 · Chemistry
The system that forms maximum boiling azeotropes is
- Correct answerAacetone-chloroform
- Bethyl alcohol-water
- Cbenzene-toluene
- D$\mathrm{CS}_2+$ acetone
Solution
Azeotropes are mixtures of liquids that boil at a constant temperature and possess the same composition in the liquid and vapor phases. Azeotropes are classified into two types based on their deviation from Raoult's Law.
Minimum boiling azeotropes are formed by solutions showing large positive deviations from Raoult's Law. Examples include ethyl alcohol-water and $\mathrm{CS}_2+$ acetone.
Maximum boiling azeotropes are formed by solutions showing large negative deviations from Raoult's Law. In these cases, the intermolecular forces between the components are stronger than the forces between the pure components, leading to a decrease in vapor pressure and an increase in the boiling point.
The mixture of acetone and chloroform exhibits strong hydrogen bonding between the oxygen atom of acetone and the hydrogen atom of chloroform, resulting in a large negative deviation from Raoult's Law. Therefore, the acetone-chloroform system forms a maximum boiling azeotrope.
Answer: acetone-chloroform
Minimum boiling azeotropes are formed by solutions showing large positive deviations from Raoult's Law. Examples include ethyl alcohol-water and $\mathrm{CS}_2+$ acetone.
Maximum boiling azeotropes are formed by solutions showing large negative deviations from Raoult's Law. In these cases, the intermolecular forces between the components are stronger than the forces between the pure components, leading to a decrease in vapor pressure and an increase in the boiling point.
The mixture of acetone and chloroform exhibits strong hydrogen bonding between the oxygen atom of acetone and the hydrogen atom of chloroform, resulting in a large negative deviation from Raoult's Law. Therefore, the acetone-chloroform system forms a maximum boiling azeotrope.
Answer: acetone-chloroform
Hence, the correct answer is option: 'A'.