Question
Mixture of chloroform and acetone forms a solution with negative deviation from Raoult's law due to :
NEET
Chemistry
Solutions
2026
NEET 2026 (Cancelled)
NEET Chemistry Question (2026) — Solution
Options
- A. increase in escaping tendency of molecules of each component.
- B. formation of hydrogen bonding between acetone and chloroform.
- C. stronger intermolecular forces between chloroform molecules than those between chloroform and acetone molecules.
- D. repulsive forces.
Answer
B. formation of hydrogen bonding between acetone and chloroform.
Step-by-step solution
Chloroform (CHCl_3) and acetone (CH_3COCH_3) form a non-ideal solution showing a negative deviation from Raoult's law. This is because the hydrogen atom of chloroform forms a hydrogen bond with the oxygen atom of acetone. The formation of this intermolecular hydrogen bond makes the attractive forces between the unlike molecules stronger than the attractive forces between the like molecules. As a result, the escaping tendency of the molecules from the liquid phase decreases, leading to a lower vapour pressure than expected from Raoult's law. Answer: formation of hydrogen bonding between acetone and chloroform.
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