Increasing Order Towards Hypnotic Activity

GUJARAT SET 2025

Increasing order of molecules towards hypnotic activity is:

• A) CHCl₃ > CHBr₃ > CHI₃
• B) CHI₃ > CHBr₃ > CHCl₃
• C) CHI₃ > CHCl₃ > CHBr₃
• D) CHCl₃ > CHI₃ > CHBr₃

Correct Answer: (B) CHI₃ > CHBr₃ > CHCl₃

The hypnotic and anesthetic potency of halogenated hydrocarbons generally increases with:

• Molecular Weight: Heavier halogens increase potency.
• Lipophilicity: Higher oil-water partition coefficients allow better penetration into the central nervous system.

Thus, Iodoform (CHI₃) is more potent than Bromoform (CHBr₃), which is more potent than Chloroform (CHCl₃).