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223336

Sigma-Aldrich

Sodium tungstate dihydrate

ACS reagent, ≥99%

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Synonym(s):
Tungstic acid sodium salt dihydrate
Linear Formula:
Na2WO4 · 2H2O
CAS Number:
Molecular Weight:
329.85
EC Number:
MDL number:
PubChem Substance ID:
NACRES:
NA.21

grade

ACS reagent

Quality Level

assay

≥99%

form

crystalline powder

reaction suitability

reagent type: catalyst
core: tungsten

impurities

≤0.01% insolubles
≤0.02 meq/g Titr. free base

pH

9-11.5 (20 °C, 100 g/L)

mp

698 °C (lit.)

anion traces

chloride (Cl-): ≤0.005%
sulfate (SO42-): ≤0.01%

cation traces

Mo: ≤0.001%
heavy metals and iron (as Pb): ≤0.001%

SMILES string

O.O.[Na+].[Na+].[O-][W]([O-])(=O)=O

InChI

1S/2Na.2H2O.4O.W/h;;2*1H2;;;;;/q2*+1;;;;;2*-1;

InChI key

WPZFLQRLSGVIAA-UHFFFAOYSA-N

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1 of 4

This Item
720693797511.06672
vibrant-m

223336

Sodium tungstate dihydrate

-
vibrant-m

72069

Sodium tungstate dihydrate

Premium Grade
vibrant-m

379751

Sodium tungstate dihydrate

-
vibrant-m

1.06672

Sodium tungstate dihydrate

-
assay

≥99%

assay

≥99.0% (T)

assay

99.995% trace metals basis

assay

≥98% (thermogravimetric)

form

crystalline powder

form

crystals

form

chunks

form

crystals

grade

ACS reagent

grade

-

grade

-

grade

-

impurities

≤0.01% insolubles, ≤0.02 meq/g Titr. free base

impurities

insoluble matter, passes filter test, ≤0.001% total nitrogen (N), ≤0.1% free alkali (as NaOH)

impurities

-

impurities

-

anion traces

chloride (Cl-): ≤0.005%, sulfate (SO42-): ≤0.01%

anion traces

chloride (Cl-): ≤50 mg/kg, sulfate (SO42-): ≤100 mg/kg

anion traces

-

anion traces

chloride (Cl-): ≤0.01%, sulfate (SO42-): ≤0.02%

General description

Sodium tungstate dihydrate is a hydrated sodium salt of tungstic acid. It participates as a catalyst in the preparation of various epoxides. Various crystallographic properties of sodium tungstate dihydrate have been analyzed.

Application

Combines with hydrogen peroxide for the oxidation of secondary amines to nitrones.
Sodium tungstate dihydrate (Na2WO4.2H2O) may be employed in the following studies:
  • As a derivatization reagent for the determination of hydrogen peroxide by a fluorimetric method.
  • Synthesis of N-hydroxy-desferrioxamine B, a metabolite of the microbial product desferrioxamine B.
  • Preparation of highly crystalline CaMoO4, SrMoO4, CaWO4 and SrWO4 nanoparticles.
Sodium tungstate dihydrate may be used in the preparation of aqueous sols of tungsten oxide dihydrate.

pictograms

Exclamation mark

signalword

Warning

hcodes

Hazard Classifications

Acute Tox. 4 Oral

Storage Class

13 - Non Combustible Solids

wgk_germany

WGK 2

flash_point_f

Not applicable

flash_point_c

Not applicable


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Journal of the Chemical Society. Chemical Communications, 874-874 (1984)
Reactions of hydrogen peroxide. IV. Sodium tungstate catalyzed epoxidation of α, β-unsaturated acids.
Payne GB and Williams PH.
The Journal of Organic Chemistry, 24(1), 54-55 (1959)
Maki Onoda et al.
Analytical sciences : the international journal of the Japan Society for Analytical Chemistry, 22(6), 815-817 (2006-06-15)
A simple batch method for the fluorometric determination of hydrogen peroxide using phosphine-based fluorescent reagents has been developed. A rapid, mild and selective derivatization reaction was achieved by adding sodium tungstate dihydrate to the reaction mixture of hydrogen peroxide and
Luminescence and absorbance of highly crystalline CaMoO4, SrMoO4, CaWO4 and SrWO4 nanoparticles synthesized by co-precipitation method at room temperature.
Thongtem T, et al.
J. Alloy Compounds, 506(1), 475-481 (2010)
B E Roggo et al.
The Journal of antibiotics, 46(2), 294-299 (1993-02-01)
N-Hydroxy-desferrioxamine B (5), a postulated metabolite of the microbial product desferrioxamine B (1), has been prepared by reduction of the intermediate oxime 6 with sodium cyanoborohydride. The oxime was obtained by selective oxidation of desferrioxamine B with hydrogen peroxide and

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