O vanadium, symbol V, is a transition metal of atomic number 23 located in group 5 of the Periodic Table. It presents several possible oxidation states, generating solutions with different and striking colors. Metal vanadium has good corrosion resistance and a grayish color.
The element is mostly used in the production of ferrovanadium alloy, which gives steel advantageous properties, such as greater mechanical and corrosion resistance. It is also an important catalyst for the industry chemical, acting in several industrial processes. The main source of vanadium is vanadinite, however, it is difficult to find a mineral in which vanadium is the main metal.
See too: Tantalum — another group 5 metal of the Periodic Table
Summary about vanadium
Vanadium is a metal transition group 5 of the Periodic table.
Its main mineral sources are vanadinite and carnotite, but it can be found in several natural sources, such as phosphate rocks and Petroleum crude.
Displays many states of oxidation possible.
It is mainly used in the manufacture of ferrovanadium alloy.
Its discovery dates from the beginning of the 19th century and its name refers to the Scandinavian goddess of beauty Vanadis.
Vanadium properties
Symbol: v.
Atomic number: 23.
Atomic mass: 50,942 c.u.s.
Electronegativity: 1,63.
Fusion point: 1910°C.
Boiling point: 3407°C.
Density: 6.0 g.cm-3 (at 18.7°C).
Electronic configuration: [Air] 4s2 3d3.
Chemical Series: group 5; transition metals.
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Vanadium Characteristics
Vanadium is a soft metal, with good corrosion resistance, gray in color. Visually, it resembles the steel. Its metallic form is insoluble in acids non-oxidizing, with the exception of hydrofluoric acid (HF), and in bases. However, it can be chemically attacked by nitric acid (HNO3) and aqua regia (a mixture of hydrochloric acid and nitric acid in high concentration).
Like many transition metals, vanadium has manyoxidation numbers possible, usually between +2 and +5. However, it is known that there are compounds in which it adopts -1 or even -3 charge. This wide variety of possible charges is perceptible through their reactions.
Upon heating, vanadium can react with either oxygen how much with halogens, as shown by the following reactions:
4V + 5O2 → 2 V2O5
2V + 5F2 → 2 VF5
V + 2 Cl2 → VCl4
2V + 3X2 → 2 VX3, with X = Br or I
Vanadium salts in which it has an oxidation number equal to +3 are quite reducing, since the +4 oxidation state is the most stable for the element.
Natural vanadium is a mixture of two isotopes, 50 (with an abundance of 0.25%) and 51 (with an abundance of 99.75%). O 50V is slightly radioactive, with a time of half life long, in the range of 3.9 x 1017 years old.
Read too: Nickel — another metal with good corrosion resistance
Where can vanadium be found?
the vanadium is the 22nd most abundant element in Earth's crust, with an estimated concentration of 97 mg/kg of soil, being considered a relatively profuse metal. There are about 65 vanadium minerals, but the metal is mostly found:
in vanadinite, Pb5(GRANDMOTHER4)3Cl;
in carnotite, K2(OU2)2(GRANDMOTHER4)·3H2O;
in roscoelite, a mica containing vanadium;
in patronite, a polysulfide of formula VS4.
Also noteworthy is the vanadium from rocks phosphates, titaniferous magnetite, bauxite and organic materials such as:
coal;
crude oil;
oil shale;
bituminous sands.
Vanadium, by the way, is the most abundant metal in petroleum, with a content of about 1600 mg/kg. In bitumen, the vanadium content can reach 4,760 mg/kg.
At world reserves of vanadium exceed 63 million tons, however, this is considered a metal that occurs spread throughout the planet. Most of the minerals that contain vanadium have it as a secondary element, and there are almost no minerals in which vanadium is the main metal.
Obtaining vanadium
Much of the metallic vanadium is obtained through of your reduction using vanadium oxide V or vanadium chloride IV. The reducers used are commonly metals. magnesium, calcium and aluminum. It is also possible to use non-metallic gearboxes, such as carbon and silicon.
Among the elements mentioned, aluminum is the most common in this context. After reduction, the vanadium needs to be refined, in order to remove traces of impurities. For this, one of the following options is generally used:
electrolysis;
purification by electronic exchange;
thermal decomposition of vanadium II iodide.
In the case of aluminum reduction, for example, high purity aluminum is used, in a method known as the Goldschmidt Process, developed in 1893. It was harnessed and used by Carlson to obtain metallic vanadium.
3 V2O5 + 10 Al ⇌ 6 V + 5 Al2O3
This experiment takes place in atmosphere in argon, and initially an alloy of vanadium and aluminum is formed with about 11% vanadium by mass. Then, at a temperature between 1700–1800 °C and in a vacuum, the aluminum comes out.
In 1927, John Marden and Malcolm Rich produced vanadium with an average purity of 99% by reducing it with calcium and chloride of calcium. In this case, the reagents were placed in a container, and the system was then heated to 900–950 °C. After the system cooled, vanadium was obtained.
V2O5 + 5 Ca + 5 CaCl2 ⇌ 2 V + 5 CaO·CaCl2
Vanadium applications
At least 80% of the vanadium obtained is used for the production of ferrovanadium alloy, used in the manufacture of steel and other alloys. Adding 0.1 to 5% vanadium to steel causes it to interact with carbon and form carbides.
As a result, steel becomes stronger, harder and has greater resistance to shock and corrosion. In tools, it is common to use steel with vanadium, but also with chromium. Vanadium steel is then used in:
cutting and construction materials;
transport and energy sectors.
Outside of metallurgy, vanadium, in the composition V2O5, it is commonly used as a catalyst in reactions organic and inorganic. They are of great economic importance, for example,
in the production of sulfuric acid, one of the most used acids throughout the chemical industry;
in the conversion of naphthalene to phthalic acid;
in the production of polyamides, such as nylon;
in the oxidation of ethyl alcohol to acetaldehyde, sugar to oxalic acid and anthracene to anthraquinone.
In addition, there is the development of vanadium batteries, which have been used for the storage of electrical energy. The advantage of vanadium is that it can coexist in four different oxidation states in an aqueous medium, producing a battery with a single electroactive element. These batteries also promise to be more durable, stable, less flammable and generate easily recycled compounds.
Biologically, vanadium seems to be essential to the human being, but its function is not yet known specifically.. The vanadate anion, (VO4)3-, and its derivatives are phosphate analogues, meaning that vanadium compounds are potential inhibitors of phosphatases, ribonucleases and ATPases.
Know more: Rhenium — another chemical element used in the manufacture of catalysts
Precautions with Vanadium
Workers exposed to V-shaped vanadium2O5 in industries reported several symptoms, such as:
respiratory irritation;
tongue with a greenish coloration;
metallic taste in the mouth;
throat irritation;
cough.
history of vanadium
The discovery of vanadium dates back to 1801., in Mexico City, by the Spanish chemist and mineralogist Don Andrés Manuel del Río. He discovered the metal from the mineral vanadinite, extracted from the city of Zimapán, Mexico.
Because of the colors of the vanadium compounds, del Río named it panchromium to the new element, but then called it a erythronium, alluding to the red color of its salts. However, the Spaniard believed that the new element was nothing more than an impure form of chromium.
Friedrich Wöhler, a German chemist, came to evaluate the vanadinite studied by Andrés del Río and found that, in fact, the Spaniard had discovered a new element. However, it is speculated that, at the time, the German was suffering from intoxications resulting from exposure to hydrofluoric acid, HF, and did not allow the publication of the studies.
As a result, vanadium was rediscovered in 1830 by the Swedish chemist Nils Gabriel Sefström. The scientist decided to name the new element vanadis, honoring the Scandinavian goddess of beauty and youth, since, in solution, vanadium compounds always presented beautiful colors.
Only In 1867, vanadium was isolated for the first time., through the work of the English chemist Henry Enfield Roscoe, from the VCl2.
Solved exercises on vanadium
question 1
(PUC Campinas-SP) Vanadium (Z = 23), a transition element, constitutes an important component of steel for produce a type of alloy that considerably improves the toughness, mechanical strength and corrosion of the iron. How many electrons are in the 3d sublevel of the vanadium electron configuration?
TO 1
B) 2
C) 3
D) 4
E) 5
Resolution:
Alternative C
when doing the eletronic distribution of chemical element vanadium, Z = 23, we have:
1s2 2s2 2p6 3s2 3p6 4s2 3d3
So, the number of electrons in the 3d sublevel is equal to 3.
question 2
Vanadium is a metal that has great importance for the chemical industry, since its compound vanadium oxide V is widely used as a catalyst. Among the alternatives, indicate the one that contains the molecular formula of vanadium oxide V.
GRANDMOTHER5
B) V2O4
C) VO3
D) V2O5
E) VO2
Resolution:
Alternative D
The name "oxide of vanadium V” indicates that the element has an oxidation number equal to +5 in that compound. As in oxides oxygen has an oxidation number of -2, the proper formula for vanadium oxide V is V2O5, as it is the only way in which the entire positive charge of vanadium is neutralized by the entire negative charge of oxygen.
By Stefano Araújo Novais
Chemistry teacher
