Carbon tetrachloride

  • Carbon tetrachloride
  • Carbon tetrachloride
  • Tetra
  • R-10
  • Tetrachloride hydrocarbon

Colorless, unpleasant, sweet -smelling liquid

Liquid

1.58 g · cm -3

-23 ° C.

76.7 ° C

119.4 hPa (20 ° C)

Very poor in water ( 0.8 g · l-1 at 20 ° C)

0

1.4630

Risk

0.5 ml · m-3

2350 mg · kg -1 ( LD50, rat, oral)

1400 ( relative to 100 years)

-128.2 KJ / mol

Template: Infobox chemical / molecular formula search available

Carbon tetrachloride (including carbon tetrachloride, tetrachloride ) is a chemical compound from the group of chlorinated hydrocarbons. For him, all the hydrogen atoms of methane are replaced by chlorine atoms. Both names are according to the IUPAC nomenclature correctly, depending on whether the compound as an organic ( carbon tetrachloride ) or inorganic ( carbon tetrachloride ) compound is viewed.

Production

Tetrachloromethane apply in the industrial production of chloroform. Use a chlorine is heated with methane or chloromethane to 400-500 ° C. At this temperature, a gradual radical substitution to carbon tetrachloride takes place:

The result of the process is a mixture of the four chloromethanes, which can be separated by distillation.

Properties

Physical Properties

Carbon tetrachloride is a colorless, highly refractive, sweet-smelling, non-flammable, poisonous liquid with a melting point of -23 ° C and a boiling point of 76.7 ° C. Tetrachloromethane is not miscible with water, ethanol, ether or gasoline, it is readily miscible and it dissolves fats, oils and resins.

Chemical Properties

Carbon tetrachloride is very inert and is not attacked by acids and alkalis. In case of contact with alkali metals and aluminum, however, an explosive reaction takes place. Under light and heat arises particularly in the presence of moisture, the poison gas phosgene. Carbon tetrachloride is one of the carcinogenic substances and is as chloroform strongly hepatotoxic. It is also harmful to aquatic organisms and contributes to ozone depletion, since it splits under UV exposure: It arise chlorine radicals, which are very harmful to the ozone effect (ozone hole in the Arctic and Antarctic).

Use

Carbon tetrachloride was used in early generations of fire extinguishers. Nowadays, however, it is no longer used because of the great toxicity of the substance for firefighters.

Because of the toxic and carcinogenic properties and also the ozone-depleting effect of carbon tetrachloride may no longer be used after chemical ozone layer Regulation. The application as a fire extinguishing agent and as degreasing, detergents, solvents and thinners is allowed only for research purposes due to its toxicity and its adverse environmental properties.

Effect on humans

Vapors of carbon tetrachloride cause depending on the inhaled concentration:

  • Headache
  • Nausea and dizziness
  • Damage of the central nervous system
  • Reduction of the sensory abilities ( visual acuity, hearing sensitivity, etc. )

For skin contact, it can be washed off with plenty of water or polyethylene glycol.

Permanent exposure leads to severe damage of the liver and kidneys. In animal experiments, tetrachloromethane, hepatocellular carcinoma, while in humans there is a justified suspicion of carcinogenic potential. For joint recording with ethanol or barbiturates occurs a potentiating effect.

CAS registry number PubChem Vapor pressure Electric dipole moment Dangerous Substances Directive (67/548/EEC) Aluminium CRC Handbook of Chemistry and Physics Integrated Authority File
163692
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