Nitrogen refers to Group 15 (old classification - the main subgroup of the fifth group), 2nd period at 7 atomic number in the periodic table of chemical elements and is represented by N. The molar mass of nitrogen equal to 14 kg / mol.
Nitrogen as a simple substance is normally inert diatomic gas not having no color, no taste, no smell.This gas is partially the Earth's atmosphere.The molecular weight of nitrogen is 28. The word "nitrogen" is translated from Greek means "dead."
In nature, the gas molecules are composed of stable isotopes in which the molar mass of 14 kg nitrogen / mol (99.635%), and 15 kg / mol (0.365%).Outside the earth's atmosphere it is found in the composition of gaseous nebulae in the solar atmosphere, interstellar space, on planets Neptune, Uranus, and so on.It is the fourth in the solar system after the dissemination of elements such as hydrogen, helium, oxygen.Artificially produced radioactive isotopes in which the molar mass of the nitrogen - from 10 kg / mol to 13 kg / mole, and from 16 kg / mol to 25 kg / mol.They all refer to short-lived elements.The most stable isotope, in which the molar mass of 13kg nitrogen / mol, a ten-minute half-life.
biological role of this gas is huge, because it is one of the main elements that make up nucleic acids, proteins, nucleoproteins, chlorophyll, hemoglobin and other important substances.Both stable isotopes and the molar mass of nitrogen 14kg / mol and 15 kg / mol is involved in nitrogen metabolism.For this reason, a tremendous amount of fixed nitrogen contain living organisms, "dead" organic and particulate matter oceans and seas.And further, as a result of decomposition and putrefaction processes of organic nitrogen-containing, nitrogen-containing organic deposits are formed such as, e.g., nitrate.
nitrogen from the atmosphere are able to bind and turn into a digestible form, for example, ammonium compounds, about 160 species of microorganisms, mainly consisting in a symbiotic relationship with higher plants, providing them with nitrogen fertilizers, and further along the food chain gets to herbivorous organisms andpredators.
in the laboratory nitrogen are produced by the decomposition of ammonium nitrite.The result is a mixture of gas with ammonia, oxygen and nitrogen oxide (I).Its Purification by passing the resulting mixture through a first solution of sulfuric acid, followed by iron sulfate (II), and then over hot copper.Another way to obtain it in the laboratory is passed over a copper oxide (II) ammonia at about 700 degrees Celsius.
Commercially prepared nitrogen by passing air over red-hot coke is formed but not a pure product, and again the mixture, but with noble gases and carbon dioxide, so-called "air" or "generator" gas.It is a raw material for chemical synthesis and fuel.Also, from the "generator" nitrogen gas can be separated, this carbon dioxide absorption is performed.The second way to produce nitrogen industry - fractional distillation of liquid air.
There are also techniques such as membrane and adsorption gas separation.Possible generation of atomic nitrogen, it is much more active than molecular, capable, for example, to react under normal conditions of phosphorus, sulfur, arsenic, metal.Nitrogen compounds are widely used in industry, because they do fertilizers, explosives, drugs, dyes and so on.In the petrochemical industry they purged lines, check their work under pressure.In the mining complex with its help create mines in explosion-proof environment, bursting their seams breed.In electronics they blown assembly in which the smallest unacceptable oxidation by oxygen contained in the air.