Sodium tungstate Property

Melting point:

3410 °C(lit.)

Boiling point:

5660 °C(lit.)

Density 

2.3 g/mL at 25 °C(lit.)

vapor pressure 

0Pa at 25℃

solubility 

H₂O: soluble

form 

wire

pka

3.5[at 20 ℃]

color 

white rhombohedral crystals, crystalline

Water Solubility 

g/100g H2O: 71.5 (0°C), 73.0 (20°C), 97.2 (100°C) [LAN05]

Merck 

13,8772

LogP

0

CAS DataBase Reference

13472-45-2(CAS DataBase Reference)

EPA Substance Registry System

Sodium tungsten oxide (Na2WO4) (13472-45-2)

Safety

Hazard Codes 

Xi

Risk Statements 

36/38

Safety Statements 

6-26-36

RIDADR 

UN 3089 4.1/PG 2

WGK Germany 

3

RTECS 

YO7175000

HazardClass 

6.1(b)

PackingGroup 

III

Hazardous Substances Data

13472-45-2(Hazardous Substances Data)

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Warning

Hazard statements

H315Causes skin irritation

H319Causes serious eye irritation

Precautionary statements

P280Wear protective gloves/protective clothing/eye protection/face protection.

P305+P351+P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.

P337+P313IF eye irritation persists: Get medical advice/attention.

Sodium tungstate Chemical Properties,Usage,Production

Chemical Properties

Sodium tungstate is a sodium salt of orthotungstate. It is a colorless crystals or white crystalline powder. Soluble in water; insoluble in alcohol and acids. noncombustible. Sodium tungstate has three crystalline forms, δ, γ and β. The transition temperature from δ to γ is about 570℃, and from γ to β is about 585℃. In hydrogen is heated to 700 ℃ also does not change, to 1100 ℃ will become metal tungsten.

Uses

Intermediate in preparation of tungsten compounds, (e.g., phosphotungstate), reagent, fire-proofing fabrics and cellulose, alkaloid precipitant.

Definition

ChEBI: Sodium tungstate is an inorganic sodium salt having tungstate as the counterion. Combines with hydrogen peroxide for the oxidation of secondary amines to nitrones. It has a role as a reagent. It contains a tungstate.

Preparation

Sodium tungstate is obtained by digestion of tungsten ores, the economically important representatives of which are tungstates, in base. Illustrative is the extraction of sodium tungstate from wolframite:
Fe/MnWO4 + 2 NaOH + 2 H2O → Na2WO4?2H2O + Fe/Mn(OH)2
Sodium tungstate can also be produced by treating tungsten carbide with a mixture of sodium nitrate and sodium hydroxide in a fusion process which overcomes the high exothermicity of the reaction involved.

Flammability and Explosibility

Not classified

Safety Profile

Poison by ingestion, intravenous, intramuscular, and subcutaneous routes. Experimental reproductive effects. Mutation data reported. When heated to decomposition it emits toxic fumes of Na2O. See also TUNGSTEN COMPOUNDS.