Thioarsenate, ammonium

Ammonium Thioarsenates. — Ammonium Orthothioarsenate, (NH4)3AsS4, separates as colourless prisms when alcohol is added to a hot solution containing arsenic pentasulphide and excess of ammonium hydrosulphide.5 The crystals gradually turn yellow in air and, when heated, melt and decompose, yielding ammonium sulphide, arsenious sulphide and sulphur. 

Reacidification reprecipitates AS2S3 quantitatively. With alkali metal or ammonium polysulfides thioarsenates are formed which are virtually insoluble even in hot cone HCl ... 

Copper Thioarsenates.—Cupric Orthothioarsenate, Cu3(AsS4)2, is formed as a dark brown precipitate when sodium orthothioarsenate is added to a solution of a cupric salt.2 The reaction, however, is complex, sulphides of copper and arsenic also being formed.3 A similar precipitate is formed when ammonium hydrosulphide or hydrogen sulphide is added to a solution of arsenic acid and a copper salt,4 and the proportion of sulphide and thio-salt in the precipitate varies with the concentration of the reactants. Copper hydroxide reacts with alkali thioarsenates to form copper sulphide and alkali arsenate, but some copper orthothioarsenate is formed and remains in solution in excess of alkali thioarsenate.5... 

The double salt, Na3(NH4)3(AsS4)2, is obtained w hen alcohol is added to a mixture of the two thioarsenates in molecular proportions, or when a solution containing ammonium chloride and sodium orthothioarsenate is allowed to evaporate it crystallises as pale yellow hexagonal prisms. A corresponding sodium-potassium salt is obtained by evaporation of a solution of the mixed orthothioarsenates.1... 

Yellow ammonium sulphide (ammonium polysulphide), (NH4)2S2 dissolves the precipitate, when thioarsenate AsS ions are formed ... 

Zinc Phenolsulfonate Calcium Phenolsulfonate Potassium Borate Titanic Acid Phosphine Sulfur Chloride Sodium Thioarsenate Arsenic Oxide Ammonium Arsenate Chlordane Amyl Acid Phosphate Butylated Hydroxytoluene Soarnol E Mercurochrome Sodium Chloride Sulfate Quinine Hydrochloride Quinine Dichloroethane Calcium Phenolsulfonate Anisoyl Chloride Xylenol... 

A neutral or slightly alkaline solution, containing sodium or ammonium thioarsenate as the active ingredient, is used in the Thylox process. Hydrogen sulfide is converted to ele-... 

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