Preparation, Properties and Uses Of Carbon Tetrachloride
Carbon tetrachloride also known as tetrachloromethane with the chemical formula CCl4 is a re-agent and an organic compound that is non-polar and quadrennial. It is a colourless liquid with a pleasant odor that is non-flammable in low temperatures.
However, due to its toxicity, there has been a huge reduction in the manufacturing of this liquid due to the danger it poses to the environment. The last record of its production was in the early 1990s when about 700,000 tonnes of it was produced by in top tier countries from Asia, North America, and Europe.
Preparation of Carbon Tetrachloride
The first recorded production of carbon tetrachloride was by a French chemist called Henry Victor in the year 1839.
Tetrachloromethane can be produced by the chlorination of methane – the simplest hydrocarbon.
Methane undergoes chlorination to form chloromethane and hydrochloric acid.
CH4 + Cl2 = CH3Cl + HCl
The chloromethane gotten from this reaction is then chlorinated to form dichloromethane and hydrochloric acid.
CH3Cl + Cl2 = CH2Cl2 + HCl
Dichloromethane is then chlorinated to produce trichloromethane which is also known as Chloroform and hydrochloric acid.
CH2Cl2 + Cl2 = CHCl3 + HCl
The resultant chloroform is then chlorinated to produce tetrachloromethane.
CHCl3 + Cl2 = CCl4 + HCl
Carbon tetrachloride is produced by the reaction of carbon disulfide with ditiodichloride. Sulphur is also formed as a by-product of this reaction.
2 S2Cl2 + CS2 = CCl4 + 6 S
Carbon tetrachloride can also be produced by the reaction of four molecules of chlorine and methane, with hydrochloric acid synthesized as a by-product.
4 Cl2 + CH4 = CCl4 + 4 HCl
Carbon tetrachloride is produced by the reaction of chlorine and hexachloroethane.
Cl2 + C2Cl6 = 2 CCl4
Carbon tetrachloride is produced by the chlorination of carbon disulfide. This reaction produces disulphur dichloride as a by-product.
3 Cl2 + CS2 = CCl4 + S2Cl2
Chemical Properties of Carbon tetrachloride
It breaks down when oxidized at high temperatures in the air to form the noxious phosgene.
CCl4 + 1/2 O2 = COCl2 + Cl2
Carbon tetrachloride reacts with sulfuric acid to produce hydrochloric acid, phosgene, and chlorosulfonic anhydride
3 CCl4 + 2 H2SO4 = 3 CCl2O + 4 HCl + Cl2O5S2
Physical Properties of Carbon tetrachloride
Carbon tetrachloride is a colourless liquid with a density of 1.5867 g.cm-3 and a heat capacity of 132.6 K. It boils at 76.72°C (170.70°F) and melts at – 22.92°C ( -9.26°F)
It is partly soluble in water and soluble in formic acid, chloroform, alcohol, benzene, and ether.
Uses of Carbon Tetrachloride
It is used as a component in the production of refrigerants.
It is used to dissolve iodine and other non-polar compounds.
Carbon tetrachloride is used in the dry cleaning industry.
Carbon tetrachloride is used to remove spots on clothes, furniture, and other household items.
In the Appel reaction, it is used as a source of chlorine.
It is used as a constituent in the production of lava lamps.
It is used in the production of fluorocarbon propellants.
It is used to set off flames, hence its use as an ingredient in the production of some fire extinguishers.
It is used to detect neutrinos.
It is used as a component in the production of chlorofluorocarbons.
It is used to uncover watermarks that are placed on stamps.
It can also be used to kill insects.
Carbon tetrachloride is used as a solvent in the rubber, varnishes, fats, and oils, paint, waxes, and resin industries amongst others. It is also used for degreasing metals and lots more.
Carbon tetrachloride is also used as a component in the production of petrol additives, ink, semiconductors, and plastics.
Health Concerns
Carbon tetrachloride is a very toxic substance to your body. Contact with your eyes and skin can cause eye and skin irritation respectively.
Exposure to vapor generated from concentrated carbon tetrachloride leads to damage to the kidney, lungs, and central nervous system. It is also highly lethal to the liver.
Being exposed to it for a long period can lead to a coma, cancer, and even death. It can also cause centrilobular hepatic necrosis.
It also has a negative effect on the environment and individuals who use them at home, which led to the reduction in its production and a ban on its consumer uses by several governments. It is also one of the substances that aid in the depletion of the ozone layer and hepatocellular damage.
People who work in industries that produce or use carbon tetrachloride, and people who live close to these industries are more liable to be exposed to it and its effects.
Meanwhile, drinking contaminated water can also lead to exposure to molecules of tetrachloromethane.
So, if you are working in a factory or industry where tetrachloromethane is used or produced, endeavor to use safety and protective clothing, which includes gloves to prevent it from touching your hands.
Make sure you also take clean water to prevent exposure to its molecules.
