Vanadium valence. Vanadium. Properties of vanadium. Applications of vanadium How vanadium is read in the periodic table

DEFINITION

Vanadium located in the fourth period of group V of the secondary (B) subgroup of the Periodic table.

Refers to elements of the d-family. Metal. Designation - V. Serial number - 23. Relative atomic mass - 50.941 amu.

Electronic structure of the vanadium atom

The vanadium atom consists of a positively charged nucleus (+23), inside of which there are 23 protons and 28 neutrons, and 23 electrons move around in four orbits.

Fig.1. Schematic structure of the vanadium atom.

The distribution of electrons among orbitals is as follows:

1s 2 2s 2 2p 6 3s 2 3p 6 3d 3 4s 2 .

The outer energy level of the vanadium atom contains 5 electrons, which are valence electrons. The oxidation state of calcium is +5. The energy diagram of the ground state takes the following form:

Based on the diagram, it can be argued that vanadium also has an oxidation state of +3.

Examples of problem solving

EXAMPLE 1

Vanadium(Vanadium), V, chemical element of group V periodic table Mendeleev; atomic number 23, atomic mass 50.942; metal gray-steel color. Natural vanadium consists of two isotopes: 51 V (99.75%) and 50 V (0.25%); the latter is weakly radioactive (half-life T ½ = 10 14 years). Vanadium was discovered in 1801 by the Mexican mineralogist A. M. del Rio in Mexican brown lead ore and named erythronium (from the Greek erythros - red) for the beautiful red color of the heated salts. In 1830, the Swedish chemist N. G. Sefström discovered a new element in iron ore from Taberg (Sweden) and named it Vanadium in honor of the Old Norse goddess of beauty Vanadis. In 1869, the English chemist G. Roscoe obtained powdered metallic Vanadium by reducing VCl 2 with hydrogen. Vanadium has been mined on an industrial scale since the beginning of the 20th century.

The content of vanadium in the earth's crust is 1.5·10 -2% by mass; it is a fairly common element, but dispersed in rocks and minerals. Of the large number of vanadium minerals, patronite, roscoelite, decloysite, carnotite, vanadinite and some others are of industrial importance. An important source of vanadium is titanomagnetite and sedimentary (phosphorous) iron ores, as well as oxidized copper-lead-zinc ores. Vanadium is extracted as a by-product during the processing of uranium raw materials, phosphorites, bauxites and various organic deposits (asphaltites, oil shale).

Physical properties of Vanadium. Vanadium has a body-centered cubic lattice with a period a=3.0282Å. In its pure state, vanadium is malleable and can be easily worked by pressure. Density 6.11 g/cm3; melting temperature 1900°С, boiling temperature 3400°С; specific heat capacity (at 20-100°C) 0.120 cal/g deg; thermal coefficient of linear expansion (at 20-1000°C) 10.6·10 -6 deg -1; electrical resistivity at 20°C 24.8·10 -8 ohm·m (24.8·10 -6 ohm·cm); Below 4.5 K Vanadium goes into a state of superconductivity. Mechanical properties of high purity vanadium after annealing: elastic modulus 135.25 n/m2 (13520 kgf/mm2), tensile strength 120 n/m2 (12 kgf/mm2), elongation 17%, Brinell hardness 700 mn /m 2 (70 kgf/mm 2). Gas impurities sharply reduce the ductility of vanadium and increase its hardness and brittleness.

Chemical properties of Vanadium. At ordinary temperatures Vanadium is not exposed to air, sea ​​water and alkali solutions; resistant to non-oxidizing acids, with the exception of hydrofluoric acid. In terms of corrosion resistance in hydrochloric and sulfuric acids, Vanadium is significantly superior to titanium and stainless steel. When heated in air above 300°C, vanadium absorbs oxygen and becomes brittle. At 600-700°C Vanadium is intensively oxidized to form V 2 O 5 oxide, as well as lower oxides. When vanadium is heated above 700°C in a nitrogen stream, nitride VN is formed (bp 2050°C), stable in water and acids. Vanadium reacts with carbon at high temperatures, yielding refractory carbide VC (mp 2800°C), which has high hardness.

Vanadium gives compounds corresponding to valences 2, 3, 4 and 5; Accordingly, the following oxides are known: VO and V 2 O 3 (basic in nature), VO 2 (amphoteric) and V 2 O 5 (acidic). Compounds of 2- and 3-valent vanadium are unstable and are strong reducing agents. Compounds of higher valences are of practical importance. Vanadium's tendency to form compounds of various valences is used in analytical chemistry and also determines the catalytic properties of V 2 O 5. Vanadium (V) oxide dissolves in alkalis to form vanadates.

Preparation of Vanadium. To extract vanadium, the following is used: direct leaching of ore or ore concentrate with solutions of acids and alkalis; roasting of the feedstock (often with NaCl additives) followed by leaching of the roasting product with water or dilute acids. Hydrated Vanadium (V) oxide is isolated from solutions by hydrolysis (at pH = 1-3). When vanadium-containing iron ores are smelted in a blast furnace, vanadium is converted into cast iron, and when processed into steel, slag containing 10-16% V 2 O 5 is obtained. Vanadium slags are roasted with table salt. The burned material is leached with water and then with dilute sulfuric acid. V 2 O 5 is isolated from solutions. The latter is used for smelting ferrovanadium (iron alloys with 35-70% vanadium) and obtaining metallic vanadium and its compounds. Malleable metal Vanadium is obtained by the calcium-thermal reduction of pure V 2 O 5 or V 2 O 3; reduction of V 2 O 5 with aluminum; vacuum carbon-thermal reduction of V 2 O 3; magnesium-thermal reduction of VCl 3 ; thermal dissociation of vanadium iodide. Vanadium is melted in vacuum arc furnaces with a consumable electrode and in electron beam furnaces.

Application of Vanadium. Ferrous metallurgy is the main consumer of Vanadium (up to 95% of all metal produced). Vanadium is part of high-speed steel, its substitutes, low-alloy tool steels and some structural steels. With the introduction of 0.15-0.25% Vanadium, the strength, toughness, fatigue resistance and wear resistance of steel sharply increase. Vanadium introduced into steel is both a deoxidizing and carbide-forming element. Vanadium carbides, distributed in the form of dispersed inclusions, prevent grain growth when steel is heated. Vanadium is introduced into steel in the form of a master alloy - ferrovanadium. Vanadium is also used for alloying cast iron. Vanadium's consumer is the titanium alloy industry; some titanium alloys contain up to 13% vanadium. Alloys based on niobium, chromium and tantalum containing vanadium additives have found use in aviation, rocket and other fields of technology. Various compositions of heat-resistant and corrosion-resistant alloys based on Vanadium with the addition of Ti, Nb, W, Zr and Al are being developed for use in aviation, rocket and nuclear technology. Superconducting alloys and compounds of Vanadium with Ga, Si and Ti are of interest.

Pure metallic Vanadium is used in nuclear energy (shells for fuel elements, pipes) and in the production of electronic devices. Vanadium compounds are used in the chemical industry as catalysts, in agriculture and medicine, in the textile, paint and varnish, rubber, ceramic, glass, photo and film industries.

Vanadium compounds are poisonous. Poisoning is possible by inhaling dust containing Vanadiz compounds. They cause irritation of the respiratory tract, pulmonary hemorrhages, dizziness, disturbances in the functioning of the heart, kidneys, etc.

Vanadium in the body. Vanadium is a constant component of plant and animal organisms. The source of Vanadium is igneous rocks and shales (containing about 0.013% Vanadium), as well as sandstones and limestones (about 0.002% Vanadium). In soils, Vanadium is about 0.01% (mainly in humus); in fresh and sea waters 1·10 -7 -2·10 -7%. In terrestrial and aquatic plants, the vanadium content is much higher (0.16-0.2%) than in terrestrial and marine animals (1.5·10 -5 - 2·10 -4%). Concentrators of vanadium are: the bryozoan Plumatella, the mollusk Pleurobranchus plumula, the sea cucumber Stichopus mobii, some ascidians, from molds - black aspergillus, from mushrooms - toadstool (Amanita muscaria).

Vanadium(vanadium), v, chemical element of group V of the periodic system of Mendeleev; atomic number 23, atomic mass 50.942; metal gray-steel color. Natural V. consists of two isotopes: 51 v (99.75%) and 50 v (0.25%); the latter is weakly radioactive (half-life T 1/2 = 10 14 years). V. was discovered in 1801 by the Mexican mineralogist A. M. del Rio in Mexican brown lead ore and was named after the beautiful red color of the heated salts erythronium (from the Greek erythr o s - red). In 1830, the Swedish chemist N. G. Sefström discovered a new element in iron ore from Taberg (Sweden) and named it V. in honor of the Old Norse goddess of beauty Vanadis. In 1869, the English chemist G. Roscoe obtained powdered metal V. by reducing vcl 2 with hydrogen. V. has been mined on an industrial scale since the beginning of the 20th century.

The V content in the earth's crust is 1.5-10 -2% by weight; it is a fairly common element, but dispersed in rocks and minerals. Of the large number of V. minerals, patronite, roscoelite, decloysite, carnotite, vanadinite, and some others are of industrial importance. Important sources of V. are titanomagnetite and sedimentary (phosphorous) iron ores, as well as oxidized copper-lead-zinc ores. V. is extracted as a by-product during the processing of uranium raw materials, phosphorites, bauxites, and various organic deposits (asphaltites, oil shale).

Physical and chemical properties. V. has a body-centered cubic lattice with a period a = 3.0282 å. In its pure state, V. is forged and can be easily processed by pressure. Density 6.11 G/ cm 3 , t pl 1900 ± 25°С, t bale 3400°C; specific heat capacity (at 20-100°C) 0.120 feces/ ggrad; thermal coefficient of linear expansion (at 20-1000°C) 10.6·10 -6 hail-1, electrical resistivity at 20 °C 24.8·10 -8 ohm· m(24.8·10 -6 ohm· cm), below 4.5 K V. it goes into a state of superconductivity. Mechanical properties of high purity V. after annealing: elastic modulus 135.25 n/ m 2 (13520 kgf/ mm 2), tensile strength 120 nm/ m 2 (12 kgf/ mm 2), elongation 17%, Brinell hardness 700 pl/ m 2 (70 kgf/ mm 2). Gas impurities sharply reduce the plasticity of fiber and increase its hardness and fragility.

At ordinary temperatures, V. is not exposed to air, sea water, and alkali solutions; resistant to non-oxidizing acids, with the exception of hydrofluoric acid. In terms of corrosion resistance in hydrochloric and sulfuric acids, V. is significantly superior to titanium and stainless steel. When heated in air above 300°C, it absorbs oxygen and becomes brittle. At 600-700°C, V. is intensively oxidized with the formation of pentoxide v 2 o 5, as well as lower oxides. When V is heated above 700°C in a nitrogen stream, nitride vn ( t mp 2050°C), stable in water and acids. V. interacts with carbon at high temperatures, giving refractory carbide vc ( t pl 2800°C), which has high hardness.

V. gives compounds corresponding to valences 2, 3, 4 and 5; Accordingly, the following oxides are known: vo and v 2 o 3 (having a basic character), vo 2 (amphoteric) and v 2 o 5 (acidic). Compounds of 2- and 3-valent vitreous are unstable and are strong reducing agents. Compounds of higher valences are of practical importance. V.'s tendency to form compounds of different valencies is used in analytical chemistry and also determines the catalytic properties of v 2 o 5. V. pentoxide dissolves in alkalis to form vanadates.

Receipt and application. To extract minerals, the following are used: direct leaching of ore or ore concentrate with solutions of acids and alkalis; firing of the raw material (often with nacl additives) followed by leaching of the fired product with water or dilute acids. Hydrated V pentoxide is isolated from solutions by hydrolysis (at pH = 1-3). When vanadium-containing iron ores are smelted in a blast furnace, V is converted into cast iron, during the processing of which slag containing 10-16% v 2 o 5 is obtained into steel. Vanadium slags are roasted with table salt. The burned material is leached with water and then with dilute sulfuric acid. V 2 o 5 is isolated from solutions. The latter is used for smelting ferrovanadium(iron alloys with 35-70% V.) and obtaining metal V. and its compounds. Malleable metal V. is obtained by calcium-thermal reduction of pure v 2 o 5 or v 2 o 3; reduction of v 2 o 5 with aluminum; vacuum carbon-thermal reduction v 2 o 3; magnesium-thermal reduction vc1 3; thermal dissociation of iodide. V. is melted in vacuum arc furnaces with a consumable electrode and in electron beam furnaces.

Ferrous metallurgy is the main consumer of metal (up to 95% of all metal produced). V. is a component of high-speed steel, its substitutes, low-alloy tool steels, and some structural steels. With the introduction of 0.15-0.25% V., the strength, toughness, fatigue resistance and wear resistance of steel sharply increase. V., introduced into steel, is both a deoxidizing and carbide-forming element. V. carbides, distributed in the form of dispersed inclusions, prevent grain growth when the steel is heated. V. is introduced into steel in the form of a master alloy - ferrovanadium. V. is also used for alloying cast iron. A new consumer of titanium is the rapidly developing industry of titanium alloys; some titanium alloys contain up to 13% V. In aviation, rocket and other fields of technology, alloys based on niobium, chromium and tantalum containing V additives have been used. Heat-resistant and corrosion-resistant alloys based on V with the addition of ti, nb have been developed. , w, zr and al, the use of which is expected in aviation, rocket and nuclear technology. Of interest are superconducting alloys and V compounds with ga, si and ti.

Pure metallic V. is used in nuclear energy (shells for fuel elements, pipes) and in the production of electronic devices.

V. compounds are used in the chemical industry as catalysts, in agriculture and medicine, in the textile, paint and varnish, rubber, ceramic, glass, photo and film industries.

V. compounds are poisonous. Poisoning is possible by inhaling dust containing compounds B. They cause irritation of the respiratory tract, pulmonary hemorrhages, dizziness, disturbances in the functioning of the heart, kidneys, etc.

V. in the body. V. is a constant component of plant and animal organisms. The source of water is igneous rocks and shales (containing about 0.013% water), as well as sandstones and limestones (about 0.002% water). In soils, V. is about 0.01% (mainly in humus); in fresh and sea waters 1·10 7 -2·10 7%. In terrestrial and aquatic plants, the content of V. is significantly higher (0.16-0.2%) than in terrestrial and marine animals (1.5·10 -5 -2·10 -4%). V. concentrators are: the bryozoan plumatella, the mollusk pleurobranchus plumula, the sea cucumber stichopus mobii, some ascidians, from molds - black aspergillus, from mushrooms - toadstool (amanita muscaria). The biological role of V. has been studied in ascidians, in whose blood cells V. is in a 3- and 4-valent state, that is, there is a dynamic equilibrium.

The physiological role of V. in ascidians is associated not with the respiratory transfer of oxygen and carbon dioxide, but with redox processes—the transfer of electrons using the so-called vanadium system, which probably has physiological significance in other organisms.

Lit.: Meerson G. A., Zelikman A. N., Metallurgy of rare metals, M., 1955; Polyakov A. Yu., Fundamentals of vanadium metallurgy, M., 1959; Rostoker U., Vanadium Metallurgy, trans. from English, M., 1959; Kieffer p., Brown H., Vanadium, niobium, tantalum, trans. from German, M., 1968; Handbook of Rare Metals, [trans. from English], M., 1965, p. 98-121; Refractory materials in mechanical engineering. Directory, M., 1967, p. 47-55, 130-32; Kovalsky V.V., Rezaeva L.T., The biological role of vanadium in ascidians, “Advances modern biology", 1965, t. 60, v. 1(4); Bowen N. j. M., trace elements in biochemistry, l. - n. y., 1966.

I. Romankov. V. V. Kovalsky.

Vanadium

VANADIUM-I; m.[lat. Vanadium from Old Scand.] Chemical element (V), a hard metal of light gray color, used to make valuable grades of steel. ● Named after the Old Norse goddess of beauty Vanadis because of the beautiful color of its salts.

◁ Vanadium, -aya, -oh. Second ores. Second steel.

(lat. Vanadium), chemical element of group V of the periodic table. The name comes from the Old Norse goddess of beauty Vanadis. Steel gray hard metal. Density 6.11 g/cm 3 t pl 1920°C. Resistant to water and many acids. It is dispersed in the earth's crust and often accompanies iron (iron ores are an important industrial source of vanadium). Alloying component of structural steels and alloys used in aviation and space technology, marine shipbuilding, component of superconducting alloys. Vanadium compounds are used in the textile, paint and varnish, and glass industries.

VANADIUM (lat. Vanadium), V (read “vanadium”), chemical element with atomic number 23, atomic weight 50.9415. Natural vanadium is a mixture of two nuclides (cm. NUCLIDE): stable 51 V (99.76% by mass) and weakly radioactive 52 V (half-life more than 3.9 10 17 years). Configuration of two outer electronic layers 3 s 2 p 6 d 3 4s 2 . In Mendeleev's periodic table it is located in the fourth period in group VB. Vanadium forms compounds in oxidation states from +2 to +5 (valency from II to V).
The radius of a neutral vanadium atom is 0.134 nm, the radius of V 2+ ions is 0.093 nm, V 3+ is 0.078 nm, V 4+ is 0.067-0.086 nm, V 5+ is 0.050-0.068 nm. The sequential ionization energies of the vanadium atom are 6.74, 14.65, 29.31, 48.6 and 65.2 eV. According to the Pauling scale, the electronegativity of vanadium is 1.63.
In its free form it is a shiny silver-gray metal.
History of discovery
Vanadium was discovered in 1801 by the Mexican mineralogist A. M. del Rio as an impurity in lead ore from a mine in Zimapan. Del Rio named the new element erythronium (from the Greek erythros - red) because of the red color of its compounds. However, he subsequently decided that he had not discovered a new element, but a variety of chromium, discovered four years earlier and still almost unstudied. In 1830, the German chemist F. Wöhler studied the Mexican mineral. (cm. WELER Friedrich) However, after being poisoned by hydrogen fluoride, he stopped research for several months. In the same year, the Swedish chemist N. Sefström (cm. SEFStröm Nils Gabriel) drew attention to the presence of an impurity in iron ore, which, along with the known elements, contained some new substance. As a result of analysis in the laboratory of J. Berzelius (cm. BERZELIUS Jens Jacob) it was proven that a new element had been discovered. This element forms compounds with beautiful colors, hence the name of the element, associated with the name of the Scandinavian goddess of beauty Vanadis. In 1831, Wöhler proved the identity of erythronium and vanadium, but the element retained the name given to it by Sefström and Berzelius.
Being in nature
Vanadium does not occur in nature in its free form; it is classified as a trace element. (cm. TRACE ELEMENTS). The content of vanadium in the earth's crust is 1.6 10 -2% by mass, in ocean water 3.10 -7%. The most important minerals: patronite V(S 2) 2, vanadinite Pb 5 (VO 4) 3 Cl and some others. The main source of vanadium is iron ores containing vanadium as an impurity.
Receipt
In industry, when obtaining vanadium from iron ores with its admixture, a concentrate is first prepared, in which the vanadium content reaches 8-16%. Next, by oxidative treatment, vanadium is converted into highest degree oxidation +5 and the sodium vanadate NaVO 3, which is easily soluble in water, is separated. When the solution is acidified with sulfuric acid, a precipitate forms, which after drying contains more than 90% vanadium.
The primary concentrate is reduced in blast furnaces and vanadium concentrate is obtained, which is then used in the smelting of an alloy of vanadium and iron - the so-called ferrovanadium (contains from 35 to 70% vanadium). Metallic vanadium can be prepared by reduction of vanadium chloride with hydrogen, calcium-thermal reduction of vanadium oxides (V 2 O 5 or V 2 O 3), thermal dissociation of VI 2 and other methods.
Physical and chemical properties
Vanadium by appearance similar to steel, it is quite hard, but at the same time ductile metal. Melting point 1920 °C, boiling point about 3400 °C, density 6.11 g/cm3. The crystal lattice is cubic, body-centered, parameter a = 0.3024 nm.
Chemically, vanadium is quite inert. It is resistant to sea water, diluted solutions of hydrochloric, nitric and sulfuric acids, and alkalis. With oxygen, vanadium forms several oxides: VO, V 2 O 3, V 3 O 5, VO 2, V 2 O 5. Orange V 2 O 5 is an acidic oxide, dark blue VO 2 is amphoteric, the remaining vanadium oxides are basic. With halogens, vanadium forms halides of the compositions VX 2 (X = F, Cl, Br, I), VX 3, VX 4 (X = F, Cl, Br), VF 5 and several oxohalides (VOCl, VOCl 2, VOF 3, etc. .).
Vanadium compounds in oxidation states +2 and +3 are strong reducing agents; in oxidation state +5 they exhibit the properties of oxidizing agents. Refractory vanadium carbide VC (t pl =2800 °C), vanadium nitride VN, vanadium sulfide V 2 S 5, vanadium silicide V 3 Si and other vanadium compounds are known.
When V 2 O 5 interacts with basic oxides, vanadates are formed (cm. VANADATES)- vanadic acid salts of probable composition H 2 .
Application
Vanadium is mainly used as an alloying additive in the production of wear-resistant, heat-resistant and corrosion-resistant alloys (primarily special steels), and as a component in the production of magnets. Vanadium oxide V 2 O 5 serves as an effective catalyst, for example, in the oxidation of sulfur dioxide SO 2 into sulfur gas SO 3 in the production of sulfuric acid. Vanadium compounds find a variety of applications in various industries (textile, glass, paint and varnish, etc.).
Biological role
Vanadium is constantly present in the tissues of all organisms in minute quantities. In plants its content (0.1-0.2%) is significantly higher than in animals (1·10 –5 -1·10 –4%). Some marine organisms - bryozoans, mollusks and, especially, ascidians - are capable of concentrating vanadium in significant quantities (in ascidians, vanadium is found in the blood plasma or special cells - vanadocytes). Apparently, vanadium is involved in some oxidative processes in tissues. Human muscle tissue contains 2·10 - 6% vanadium, bone tissue - 0.35·10 - 6%, in blood - less than 2·10 - 4% mg/l. In total, the average person (body weight 70 kg) contains 0.11 mg of vanadium. Vanadium and its compounds are toxic. The toxic dose for humans is 0.25 mg, the lethal dose is 2-4 mg. For V 2 O 5 the maximum permissible concentration in air is 0.1-0.5 mg/m 3 .

encyclopedic Dictionary. 2009 .

See what “vanadium” is in other dictionaries:

- (lat. vanadium). A fragile metal, white in color, discovered in 1830 and named after the Scandinavian deity Vanadium. Dictionary of foreign words included in the Russian language. Chudinov A.N., 1910. VANADIUM lat. vanadium, named Vanadia,... ... Dictionary of foreign words of the Russian language

- (chemical value V, atomic weight 51) a chemical element similar to compounds with phosphorus and nitrogen. V. compounds are often found, although in negligible quantities, in iron ores and some clays; pre-processing of vanadic iron ores, V. part... ... Encyclopedia of Brockhaus and Efron

Vanad Dictionary of Russian synonyms. vanadium noun, number of synonyms: 2 vanadium (1) element... Synonym dictionary

VANADIUM- VANADIUM, chemical. sign V, at. V. 51.0, hard, elastic steel-colored metal, melting point 1715°, sp. weight 5.688. V. compounds are widespread in nature. These compounds are poisons, not inferior in strength to arsenic; they have... ... Great Medical Encyclopedia

- (Vanadium), V, chemical element of group V of the periodic system, atomic number 23, atomic mass 50.9415; metal, melting point 1920°C. Used for alloying steel and cast iron, as a component of heat-resistant, hard and corrosion-resistant alloys, as... Modern encyclopedia

- (lat. Vanadium) V, chemical element of group V of the periodic system, atomic number 23, atomic mass 50.9415. The name comes from the Old Norse goddess of beauty Vanadis. Steel gray hard metal. Density 6.11 g/cm³, melting point 1920 .C.… … Big Encyclopedic Dictionary

- (symbol V), TRANSITION ELEMENT, discovered in 1801. Silvery-white, malleable, tough metal. Found in IRON, LEAD AND URANIUM ores, as well as in coal and oil. Used in steel alloys to increase strength and heat resistance.… … Scientific and technical encyclopedic dictionary Physical encyclopedia

vanadium- V Element of group V Periodic. systems; at. n. 23, at. m. 50.942; steel gray metal. Natural V consists of two isotopes: 51V (99.75%) and 50V (0.25%). V was opened in 1801 Mexico. mineralogist A. M. del Rio. In prom. V scale... ... Technical Translator's Guide