What are the chemical properties of carbon


Carbon is unique in its chemical properties because it forms a compound with a large number of elements. The number of carbon compounds is far greater than the total number of compounds which all other elements together form with one another.

The largest group of these compounds is that formed by carbon and hydrogen.
We know of a minimum of about 1 million organic compounds and this number is increasing every year. Although the classification is not strict, carbon is much less present in inorganic compounds than in organic substances.

Elemental carbon comes in two crystalline forms: diamond and graphite. Other forms
with little crystallinity are vegetative carbon and soot. Chemically pure carbon is produced by the thermal breakdown of sugar (sucrose) in the absence of air. The physical and chemical properties of carbon depend on the crystalline structure of the element.
Its density varies between 2.25 g / cm³ for graphite and 3.51 g / cm³ for diamonds.
The melting point of the graphite is 3500 ° C (6332 ° F) and the extrapolated boiling point is 4830 ° C. Elemental carbon is an inert substance that is insoluble in water, in dilute acids and bases, and in organic solvents.
At high temperatures it binds with oxygen and forms carbon monoxide or dioxide. When reacting with hot oxidizing agents such as nitric acid and potassium nitrate, metallic acid, C, is formed6 (Co2H)6Among halogens, only fluorine reacts with elemental carbon. A large number of metals react to form carbides with the element at high temperatures.

It forms three gaseous compounds with oxygen: carbon monoxide, carbon dioxide and carbon suboxide (C.3O2).
The first two compounds are the most important from an industrial point of view. With halogens, carbon forms many compounds of the type: CX 4 - general formula. X stands for fluorine, chlorine, bromine or iodine. At ambient temperatures only carbon tetrafluoride is a liquid, the other two halogen compounds are solid. There are also mixed carbon tetrafluorides. The most important of these can be dichlorodifluoromethane (CCl2F.2) are viewed- called "Freon".

Carbon and its compounds are widespread in nature. It is estimated that carbon makes up 0.032% of the earth's crust. Free carbon is found in large quantities as coal, an amorphous form of the element in conjunction with other complex compounds
of carbon-hydrogen-nitrogen. Pure crystalline carbon is found as graphite and diamond.

Large amounts of carbon are found in the form of compounds. With 0.03% carbon in the form of carbon dioxide in the air, it is part of the atmosphere. Some minerals, such as limestone, dolomite, gypsum, and marble, contain carbonates. All plants and living animals are created from intricate organic compounds that combine carbon with hydrogen, oxygen, nitrogen and other elements. The remains of living plants and animals form deposits: petroleum, asphalt and bitumen. The natural gas reservoirs contain the compounds formed by carbon and hydrogen.

As a free element, carbon has a lot of uses. These include decorative purposes for diamonds in the jewelry industry, vapor deposition of black pigment paint for rims in the automotive industry and use in the form of printing ink. Another form of carbon
graphite is used for high-temperature crucibles, dry cells and arc electrodes, for pencil tips and as a lubricant. Vegetative carbon, an amorphous form of carbon, is used as a gas absorbent and a bleaching agent.

Carbon compounds have many uses. Carbon dioxide is used in beverage carbonation, in fire extinguishers and in solids, as well as for cooling purposes (dry ice). Carbon monoxide is used as a reducing agent in many metallurgical processes. Carbon tetrachloride and carbon disulfide are important industrial solvents. Freon is used in cooling systems. Calcium carbide is used to make acetylene. It is used for welding and cutting metals, as well as for the production of other organic compounds. Other metallic carbides have important uses as refractory materials and metal cutters.

Health effects of carbon

Elemental carbon is very low in toxicity. The hazard data for health,
shown here are based on exposures to soot not elemental carbon.
Chronic inhalation of soot can cause temporary or permanent damage to the lungs and heart. Dust infections developed among workers exposed to soot in production.

Hair follicle inflammation and oral mucosal injury from soot exposure of the skin have also been reported. The carcinogenicity of carbon black has been classified into Group 3 by the International Agency for Research on Cancer (IARC) (the compound is not classifiable for its carcinogenicity to humans).
Carbon 14 is one of the radionuclides involved in atomic weapons tests in the atmosphere, which began in 1945 by the Americans with the US test and ended with tests by the Chinese in 1980. Carbon is one of the long-lived radionuclides that have caused an increased risk of cancer so far and in the following decades and centuries. Carbon 14 can also penetrate the uterus and be organically bound to cells that are still developing, which can increase the risk to fetuses.

Environmental effects of carbon

There are no known negative consequences for the environment.

Back to the periodic table of the elements

More information about the position of carbon in the environment can be found on the page:

Carbon cycle