The question asks for the common name of Trichloromethane.

Trichloromethane is a chemical compound with the formula CHCl<sub>3</sub>. It is an organic compound belonging to the class of halomethanes.

Understanding Trichloromethane and its Common Name

Organic compounds often have both a systematic chemical name, based on IUPAC nomenclature rules, and one or more common names that are widely used, especially historically or in specific industries. Trichloromethane is one such compound with a very well-known common name.

Let's look at the options provided to identify the common name of Trichloromethane:

• butanes: Butanes are saturated hydrocarbons with the chemical formula C<sub>4</sub>H<sub>10</sub>. There are two isomers: n-butane and isobutane. They are not Trichloromethane.
• LPG: LPG stands for Liquefied Petroleum Gas. It is a mixture of hydrocarbon gases, primarily propane and butane. It is a fuel and not a single chemical compound like Trichloromethane.
• chloroform: Chloroform is the historical and common name for Trichloromethane (CHCl<sub>3</sub>). It was widely used as an anesthetic in the past, although its use has declined due to safety concerns.
• laughing gas: Laughing gas is the common name for nitrous oxide (N<sub>2</sub>O). It is used as a mild anesthetic and analgesic, particularly in dentistry. It is not Trichloromethane.

Based on chemical nomenclature and common usage, Trichloromethane is universally known by the common name chloroform.

Summary of Options

Therefore, Trichloromethane is better known as chloroform.

Revision Table: Common Names of Chemicals

Additional Information on Trichloromethane (Chloroform)

Trichloromethane, or chloroform, is a colorless, volatile liquid. It has a strong, ether-like odor. Historically, its primary use was as an anesthetic. However, due to its toxicity, particularly its effects on the liver and kidneys, and its potential carcinogenicity, it is no longer widely used for surgical anesthesia in humans. It is still used in some veterinary practices.

Modern uses of chloroform include:

• As a solvent in laboratories and industry.
• In the production of other chemicals, such as chlorofluorocarbons (though their use is declining due to environmental concerns) and refrigerants.
• As a reagent in various organic synthesis reactions.

Handling chloroform requires care due to its health hazards and flammability (though it is less flammable than many organic solvents).