8698. Sodium Tungstate(VI)

Nomenclature

CAS number: 13472-45-2
Sodium (T-4)-tungstate (WO42) (2:1).
Na2O4W; mol wt 293.82.
Na 15.65%, O 21.78%, W 62.57%.
Na2WO4.

Description and references

Crystals have a spinel structure isomorphous with sodium molybdate(VI), q.v. Mfr: N. T. Gordon, A. F. Spring, Ind. Eng. Chem. 16, 555 (1924). Properties of sodium tungstate derivatives: E. F. Smith, J. Am. Chem. Soc. 44, 2027 (1922). Crystal structure: I. Lindqvist, Acta Chem. Scand. 4, 1066 (1950). Polymerization study: M. L. Freedman, J. Am. Chem. Soc. 80, 2072 (1958). Thermochemistry study: R. L. Graham, L. G. Hepler, ibid. 3538. HPLC and CZE analysis: K. Hettiarachchi et al., J. Pharm. Biomed. Anal. 13, 515 (1995). Pharmacokinetics in rats: S. Le Lamer-Déchamps et al., Int. J. Pharm. 248, 131 (2002). Antidiabetic effects in rats: A. Barberà et al., Diabetologia 44, 507 (2001). Review of toxicity: B. Venugopal, T. D. Luckey, Environ. Qual. Safety, Suppl. 1, 4-73 (1975); of toxicology and human exposure: Toxicological Profile for Tungsten (PB2006-100007, 2005) 203 pp.

Derivative

Dihydrate.

Nomenclature

CAS number: 10213-10-2
Na2O4W.2H2O; mol wt 329.85.
Na 13.94%, O 29.10%, W 55.73%, H 1.22%.

Properties

Colorless crystals or white, cryst powder, mp 665°. Effloresces in dry air. Loses its water at 100°. Sol in about 1.1 parts water. Insol in alcohol. The aq soln is slightly alkaline, pH 8-9. LD50 (mg tungstate/kg) in rabbits: 105 i.m.; in rats: 240 s.c. (Venugopal, Luckey).

Use

Fireproofing and waterproofing fabrics; preparing complex compds such as phosphotungstate and silicotungstate; as a protective colloid in biological development methods; precipitant for alkaloids and proteins; catalyst in oxidation reactions; corrosion inhibitor for steel.