Basic Information

Trichloromethane

Colorless transparent liquid. Has a special smell. Sweet. High refractive index, non-flammable, heavy and volatile. The pure product is sensitive to light. When exposed to light, it will react with oxygen in the air and gradually decompose to generate highly toxic phosgene (carbonyl chloride) and hydrogen chloride. 0.6%~1% ethanol can be added as stabilizer. It is miscible with ethanol, benzene, ether, petroleum ether, carbon tetrachloride, carbon disulfide and oil, etc. 1ml dissolves in 200ml water at 25℃. Relative density 1.4840. Freezing point -63.5 ℃. Boiling point 61~62℃. Refractive index 1.4476. Low toxicity, median lethal dose (rat, oral) 1194mg/kg. There is anesthesia. Possibly carcinogenic.

Function and use

Organic synthetic raw materials, mainly used to produce freon (F-21, F-22, F-23), dyes and drugs, in medicine, commonly used as anesthetics. It can be used as a solvent and extractant for antibiotics, spices, oils, resins, and rubber. It can be mixed with carbon tetrachloride to make a non-freezing fireproof liquid. Also used as propellant for aerosols, fumigants for grains and standard solutions for temperature calibration. Industrial products are usually added with a small amount of ethanol, so that the generated phosgene reacts with ethanol to form non-toxic diethyl carbonate. Before using the industrial product, a small amount of concentrated sulfuric acid can be added, shaken, washed with water, and dried with calcium chloride or potassium carbonate to obtain ethanol-free chloroform.

chemical properties

The scale model of chloroform is gradually oxidized to form highly toxic phosgene when exposed to air under light, so it needs to be stored in a sealed brown bottle. Often 1% ethanol is added to destroy the phosgene that may be formed. It is not easy to burn, and can be oxidized into hydrogen chloride and highly toxic phosgene by oxygen in the air under the action of light. It is most easily hydrolyzed into formic acid and HCl in methyl chloride, with poor stability, thermal decomposition occurs above 450 ℃, and it can be further chlorinated to CCl4.