Which haloform was used as a general anaesthetic in surgery earlier b…

The correct answer is Option (2) → CHCl₃

A haloform is a trihalomethane, \( \ce{CHX3} \). Polyhalogen compounds have important uses, but many of them are toxic:

• Chloroform (CHCl₃): used as a solvent for fats, alkaloids and iodine, and in making the refrigerant R-22. It was once used as a general anaesthetic in surgery, but it has been replaced by less toxic, safer anaesthetics such as ether. Inhaling it depresses the central nervous system and can damage the liver.

• Iodoform (CHI₃): formerly used as an antiseptic because it releases free iodine; replaced because of its objectionable smell.

• Carbon tetrachloride (CCl₄): used as a solvent and in making refrigerants and propellants. It is not a haloform; it damages the liver and depletes the ozone layer.

So the haloform once used as a general anaesthetic is chloroform, CHCl₃.

NCERT (2026-27 edition):
Trichloromethane (Chloroform) – “Chemically, chloroform is employed as a solvent for fats, alkaloids, iodine and other substances. The major use of chloroform today is in the production of the freon refrigerant R-22. It was once used as a general anaesthetic in surgery but has been replaced by less toxic, safer anaesthetics, such as ether.”