Sodium molybdate 2845369 221109664 2008-06-23T02:28:57Z Steviedpeele 1322814 replaced image of the structure with one that was more clearer and of higher quality {{Chembox new | Name = Sodium molybdate | ImageFile = Sodium molybdate.jpg | ImageFile1 = Sodiummolybdate.png | ImageName = Sodium molybdate | IUPACName = Sodium molybdate(VI) | OtherNames = Disodium molybdate. | Section1 = {{Chembox Identifiers | CASNo = 7631-95-0 }} | Section2 = {{Chembox Properties | Formula = Na<sub>2</sub>MoO<sub>4</sub> | MolarMass = Anhydrous 206 g/mol Dihydrate 241.95 g/mol | Appearance = White powder. | Density = 3.78 g/cm<sup>3</sup>, solid | Solubility = 65.5 g/100 g Water | MeltingPt = 687°C | BoilingPt = }} | Section7 = {{Chembox Hazards | ExternalMSDS = [http://ptcl.chem.ox.ac.uk/MSDS/SO/sodium_molybdate.html External MSDS] | EUClass = Irritant ('''I''') | RPhrases = {{R36}}, {{R37}}, {{R38}}. | SPhrases = None listed. | FlashPt = Non-flammable. }} | Section8 = {{Chembox Other | OtherAnions = None listed. | OtherCations = None listed. | Function = [[base (chemistry)|base]]s }} }} '''Sodium molybdate''', Na<sub>2</sub>MoO<sub>4</sub>, is useful as a source of [[molybdenum]].{{Fact|date=March 2008}} It is often found as the dihydrate, Na<sub>2</sub>MoO<sub>4</sub>·2H<sub>2</sub>O. The molybdate(VI) anion is tetrahedral. Two sodium cations coordinate with every one anion.<ref name = Braithwaite>Braithwaite, E.R.; Haber, J. ''Molybdenum: An outline of its Chemistry and Uses.'' 1994. Elsevier Science B.V. Amsterdam, The Netherlands.</ref> ==History== Sodium molybdate was first synthesized by the method of hydration.<ref>Spitsyn, Vikt. I.; Kuleshov, I. M. ''Zhurnal Obshchei Khimii'' 1951. 21. 1701-15. </ref>; A more convenient synthesis is done by dissolving [[Molybdenum(VI) oxide|MoO<sub>3</sub>]] in [[sodium hydroxide]] at 50-70 °C and crystallizing the filtered product.<ref name = Braithwaite/> The anhydrous salt is prepared by heating to 100 °C. :MoO<sub>3</sub> + 2NaOH → Na<sub>2</sub>MoO<sub>4</sub>&middot;2H<sub>2</sub>O ==Uses== Sodium molybdate is used in biochemistry and medicinal chemistry to track various organic chemicals that are colorless after a chromatographical procedure, which it always stains blue. The blue color is also called [[molybdenum blue]]. The agriculture industry uses 1 million pounds per year as a fertilizer. However, care must be taken because at a level of 0.3 ppm sodium molybdate can cause copper deficiencies in animals, particularly cattle.<ref name = Braithwaite/> It is used for water treatment.{{Fact|date=March 2008}} It is used in industry for corrosion inhibition, as it is a non-oxidizing anodic inhibitor.<ref name = Braithwaite/> The addition of sodium molybdate significantly reduces the nitrite requirement of fluids inhibited with nitrite-amine, and improves the corrosion protection of carboxylate salt fluids.<ref>Vukasovich, Mark S. ''Lubrication Engineering'' 1980. 36(12). 708-12. </ref> According to an article from 1950 that was published in Nature, sodium molybdate is useful for curing a broccoli disease known as ‘whiptail’.{{Fact|date=March 2008}} ==Reactions== When reacted with [[sodium borohydride]], molybdenum is reduced to a lower valent oxide:<ref>Chi Fo Tsang and Arumugam Manthiram. ''Journal of Materials Chemistry'' 1997. 7(6). 1003–1006.</ref> :Na<sub>2</sub>MoO<sub>4</sub> + NaBH<sub>4</sub> + 2H<sub>2</sub>O→ NaBO<sub>2</sub> + MoO<sub>2</sub>+2NaOH+ 3 H<sub>2</sub> Sodium molybdate reacts with the acids of dithiophosphates:<ref name = Braithwaite/> :Na<sub>2</sub>MoO<sub>4</sub> + (RO)<sub>2</sub>PS<sub>2</sub>H (R = Me, Et) → [MoO<sub>2</sub>(S<sub>2</sub>P(OR)<sub>2</sub>)<sub>2</sub>] which further reacts to form [MoO<sub>3</sub>(S<sub>2</sub>P(OR)<sub>2</sub>)<sub>4</sub>]. ==Precautions== Sodium molybdate is incompatible with alkali metals, most common metals and oxidizing agents. It will explode on contact with molten magnesium. It will violently react with interhalogens (e.g., bromine pentafluoride; chlorine trifluoride). Its reaction with hot sodium, potassium or lithium is incandescent.{{Fact|date=March 2008}} ==References== {{reflist}} ==See also== * [[xanthine oxidase]] ==External links== * [http://lpi.oregonstate.edu/infocenter/minerals/molybdenum/ Linus Pauling Institute page on molybdenum]. [[Category:Molybdates]] [[Category:Sodium compounds]] [[Category:Dietary minerals]] [[Category:Inorganic compounds]] [[ar:موليبدات صوديوم]]