Title:  Vanadium Pentoxide 
CAS Registry Number:  1314-62-1 
CAS Name:  Vanadium oxide (V2O5) 
Additional Names:  vanadic anhydride 
Molecular Formula:  O5V2 
Molecular Weight:  181.88 
Percent Composition:  O 43.98%, V 56.02% 
Line Formula:  V2O5 
Literature References:  Prepd by heating ammonium metavanadate, NH4VO3. 
Properties:  Yellow to rust-brown orthorhombic crystals; d 3.35; mp 690°.  Loses oxygen reversibly in the region 700-1125°.  One gram dissolves in ~125 ml water; sol in concd acids, forming red to yellow solns; sol in alkalies, forming vanadates; insol in alcohol.  Its acid solutions are reduced by SO2, Zn + HCl, and by evaporation with HCl. 
Melting point:  mp 690° 
Density:  d 3.35 
CAUTION:  Reported to be a respiratory irritant and to cause skin pallor, greenish-black tongue, chest pain, cough, dyspnea, palpitation, lung changes.  When ingested, causes G.I. disturbances.  May also cause a papular skin rash:  Zenz et al., Arch. Environ. Health 5, 542 (1962); E. Browning, Toxicity of Industrial Metals (Appleton-Century-Crofts, New York, 2nd ed., 1969) pp 340-347. 
Use:  As catalyst in the oxidation of SO2 to SO3, alcohol to acetaldehyde, etc.; for the manuf of yellow glass; inhibiting ultraviolet light transmission in glass; depolarizer; as developer in photography; in form of ammonium vanadate as mordant in dyeing and printing fabrics and in manuf of aniline black.   |