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Vanadium | |||
Common oxidation states of vanadium include +2, +3, +4 and +5. A popular experiment with ammonium vanadate (NH4VO3), reducing the compound with zinc metal, can demonstrate colorimetrically all four of these vanadium oxidation states. A +1 oxidation state is also rarely seen.
In 1831, Sefström of Sweden rediscovered vanadium in a new oxide he found while working with some iron ores and later that same year Friedrich Wöhler[?] confirmed del Rio's earlier work.
Metallic vanadium was isolated by Henry Enfield Roscoe[?] in 1867, who reduced the vanadium chloride[?] (VCl3) with hydrogen. The name vanadium comes from Vanadis[?], the goddess of beauty in Scandinavian mythology because the element has beautiful multicolored chemical compounds.
Administration of oxovanadium compounds has been shown to alleviate diabetes mellitus symptoms in certain animal models and humans. Much like the chromium effect on sugar metabolism, the mechanism of this effect is unknown.
Much of the vanadium metal being produced is now made by calcium reduction of V2O5 in a pressure vessel. Vanadium is usually recovered as a by-product or co-product, and so world resources of the element are not really indicative of available supply.
The isotopes of vanadium range in atomic weight from 43.981 amu (V-43) to 59.959 amu (V-59). The primary decay mode before the most abundant stable isotope, V-51, is electron capture and the primary mode after is beta decay. The primary decay products before V-51 are element 22 (titanium) isotopes and the primary products after are element 24 (chromium) isotopes.
The Occupational Safety and Health Administration (OSHA) has set an exposure limit of 0.05 mg/m3 for vanadium pentoxide dust and 0.1 mg/m3 for vanadium pentoxide fumes in workplace air for an 8-hour workday, 40-hour work week.
The National Institute for Occupational Safety and Health[?] (NIOSH) has recommended that 35 mg/m3 of vanadium be considered immediately dangerous to life and health. This is the exposure level of a chemical that is likely to cause permanent health problems or death.
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