Tungsten Compounds Sodium tungstate

A considerable difference in the toxicity of soluble and insoluble compounds of tungsten has been reported (58). For soluble sodium tungstate,... 

Orally in rats, the toxicity of sodium tungstate was highest, tungsten trioxide was intermediate, and ammonium tungstate [15855-70-6] lowest (59,60). In view of the degree of systemic toxicity of soluble compounds of tungsten, a threshold limit of 1 mg of tungsten per m of air is recommended. 

Thiosalts and Sulphides of Molybdenum and Tungsten. Pour 2-3 ml of an ammonium molybdate solution into one test tube and 2-3 ml of a sodium tungstate solution into another one. Add 2-3 drops of a 25 % ammonia solution to each solution and pass a stream of hydrogen sulphide through them from a Kipp gas generator. What compounds form Acidify the solutions with a 10% hydrochloric... 

Reduction of MoIybdenum(VI) and Tungsten VI) Compounds. Pour 3 ml of an ammonium molybdate solution into each of four test tubes, acidify with a 2 N hydrochloric acid solution, and heat up to boiling. Add solutions of sulphuric acid, hydrogen sulphide, and tin(Il) chloride to three of the tubes, respectively, and throw one or two small pieces of zinc into the last tube. Perform similar experiments using sodium tungstate as the initial reactant. Write the equations of the reactions. 

Molybdenum and Tungsten Peroxide Compounds. Pour ammonium molybdate and sodium tungstate solutions into separate test tubes, acidify them with sulphuric acid, and add several drops of a 1 % hydrogen peroxide solution to each tube. How does the colour of the solutions change Write the equations of the reactions. 

Trichloroisopropoxytitanium, 300 Trichloromethyltitanium, 216 Triisopropoxymethyltitanium, 213 Triisopropoxy[ l-(trimethylsilyl)-l, 2-bu-tadienyljtitanium, 218 Tungsten Compounds /rans-Bromotetracarbonyl(methyl-methylidyne)tungsten, 49 Hydrogen peroxide-Sodium tungstate, 145... 

Sodium tungstate, 145 Tungsten carbonyl, 49 Vanadium Compounds Alkynylvanadium(III) chloride,... 

A hydrosol of tungsten hydroxide is readily produced by the electrolysis of a 2 per cent, solution of sodium tungstate between a mercuiy cathode and a silver anode in a Hildebrand cell. The solution must not be allow ed to become acid, or blue compounds are produced. The hydrosols obtained in this way are clear and transj arent but brown in colour. The addition of potassium chloride causes coagulation, a black powder, resembling the lower oxides of tungsten, being formed. ... 

Bersch (1901) describes Tessie du Motay s blue as prepared from 10 parts sodium tungstate, 8 parts tin crystals , 5 parts yellow prussiate and 1 part of iron(lll) chloride these are dissolved separately and mixed. The precipitate is washed and exposed to light in thin layers, with the blue colour developing over a period of a few days. According to the discoverer, the pigment consists of a compound of tungsten oxide with a double cyanide of iron and tin . 

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