Wednesday, April 10, 2013

Vanadium (23)

Pure vanadium is a greyish silvery metal, and is soft and ductile. It has good corrosion resistance to alkalis, sulphuric acid, hydrochloric acid, and salt waters. The metal oxidizes readily above 660°C to form V2O5. Industrially, most vanadium produced is used as an additive to improve steels.

•Name: Vanadium
•Symbol: V
•Atomic number: 23
•Atomic weight: 50.9415
•Standard state: solid at 298 K
•CAS Registry ID: 7440-62-2
•Group in periodic table: 5
•Period in periodic table: 4
•Block in periodic table: d-block
•Color: silvery grey metallic
•Classification: Metallic

Historical information

Vanadium was discovered by Andres Manuel del Rio and Nils Sefström at 1801 in Mexico and Sweden. The element was named after "Vanadis", (a by-name of Freya referring to beauty and fertility) in Norse mythology. In 1831, Nils Gabriel Sefström (a Swedish chemist) was working with some iron ores and was able to isolate a new oxide. This lead to the element being named in honor of the Northern-Germanic tribes' goddess Vanadis  because of its beautiful multicolored compounds. In the same year, Friedrich Wöhler came in to possession of del Rio's "brown lead" and confirmed del Rio's discovery of vanadium, although the name vanadium still stands rather than del Rio's suggestion of erythronium.
The discovery of vanadium happened "twice". The discovery of vanadium was claimed first by Andres Manuel del Rio (a Spanish mineralogist) at Mexico City in 1803. He prepared a number of salts from a material contained in "brown lead" (now called vanadite, from a mine near Hidalgo in Northern Mexico). He found the colors reminiscent of those shown by chromium, so he called the element panchromium ("something which can take or have any color"). He later renamed the element erythronium ("red") [similar to erythrocytes, or red blood cells!] after noting that most of these salts turned red upon heating. It seems he withdrew his claim after a Frenchman, Collett-Desotils, disputed his claim, and it was only 30 years later that it was shown that del Rio's work was, in fact, correct.

Metallic vanadium was not made until 1867 when Henry Enfield Roscoe reduced vandium chloride (VCl3) with hydrogen gas to give vanadium metal and HCl.

Physical properties

•Melting point: 2183 [or 1910 °C (3470 °F)] K
•Boiling point: 3680 [or 3407 °C (6165 °F)] K
•Density of solid: 6110 kg m-3

Orbital properties

•Ground state electron configuration: [Ar].3d3.4s2
•Shell structure: 2.8.11.2
•Term symbol: 4F3/2

Isolation

Vanadium is available commercially and production of a sample in the laboratory is not normally required. Commercially, routes leading to metallic vanadium as main product are not usually required as enough is produced as byproduct in other processes.

In industry, heating of vanadium ore or residues from other processes with salt, NaCl, or sodium carbonate, Na2CO3, at about 850°C gives sodium vanadate, NaVO3. This is dissolved in water and acidified to give a red solid which in turn is melted to form a crude form of vanadium pentoxide, "V2O5". Reduction of vanadium pentoxide with calcium, Ca, gives pure vanadium. An alternative suitable for small scales is the reduction of vanadium pentachloride, VCl5, with hydrogen, H2, or magnesium, Mg. Many other methods are also in use.

Industrially, most vanadium is used as an additive to improve steels. Rather than proceed via pure vanadium metal it is often sufficient to react the crude of vanadium pentoxide, "V2O5", with crude iron. This produces ferrovanadium suitable for further work.

Interesting Facts:

Vanadium (English) Vanadium (German) Vanadium (French) Vanadio (Italian) Vanadio (Spanish) Vanadin (Swedish)

• Vanadium is a transition element.

• Vanadium lies in the middle of the periodic table, in group 5.

• The number of electrons and protons in the vanadium atom is 23 while the number of neutrons is 28.

• The crystal structure of vanadium atom is cubic.

• Vanadium has a bright lustrous white color.

• Its compounds form different colors.

•It is highly ductile but not really malleable.

•Since it is not very reactive, vanadium does not react with oxygen or acids. However, it does react with hot sulfuric and nitric acid.

•Its specific heat capacity is 0.49 J g-1K-1.

•One of the peculiar characteristics of this element is that at times, it acts as a metal and sometimes as a non-metal.

•Vanadium is obtained from the minerals vanadinite, carnotite, roscoelite and patronite.

•For commercially producing vanadium, it is extracted from slag (mixture of materials which get separated from iron on purifying and float on top) and fly ash (powdered material for purifying iron)

•Vanadium is used to make strong steel alloys to be used in space vehicles, aircraft carriers, etc.

•Vanadium alloys are highly rust resistant. This makes them an excellent choice for tools and heavy equipment.

•Vanadium is also used to some extent in ceramics.

•Vanadium pentoxide can be used as a catalyst in the manufacture of dyes and printing fabrics.

•Superconducting magnets can be made from vanadium gallium tape.

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