Sodium thioarsenates

Chloroprene Delrin 500F Texin 480AR Lead Chloride Sodium Thioarsenate Sodium Thioarsenate Sodium Thioarsenate Dowfax 2A1 Silicate Aroclor 5442 Lead Bromide Potassium Perborate Aroclor 1248 Potassium Borate Sodium Chromate Potassium Acetate Sodium Acetate Pyruvic Acid Perchloroethylene Perclene Tetrach loroethylene Dimethylacetamide Dimethyl Acetamide (N.N-) Methyl Abietate Aktivin... 

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 small quantity of arsenic is precipitated in each case. Sodium dihydrogen arsenite yields a considerable precipitate of arsenic and also of the red disulphide. The polythionates react similarly to thiosulphates, yielding sulphite, thioarsenate and arsenate.5 The per- 1 ites also cause oxidation to arsenate. Sodium hydrosulphite... 

If finely powdered realgar is heated with aqueous sodium sulphide in a sealed tube at 100° C., a thioarsenate is formed and arsenic, which may be contaminated with sulphur, is precipitated.12 Heated with arsenious oxide, metallic arsenic sublimes and sulphur dioxide is evolved.13... 

Antimony Thioarsenate.—When sodium orthothioarsenate is added to a solution of an antimonious salt, a brownish-yellow precipitate is produced.3... 

Cerium Thioarsenates.—The addition of sodium orthothio-arsenate to an aqueous solution of a cerous salt produces a pale yellow precipitate of cerous orthothioarsenate.1 With sodium hydrogen ortho-thioarsenate the precipitate approximates in composition to cerous pyro-thioarsenate. Ceric salts also give pale yellow precipitates, probably ceric orthothioarsenate. Thioarsenates of other rare earth metals have not been described. 

Chromium Thioarsenate.—Sodium orthothioarsenate gives a yellow precipitate when added to an aqueous solution of a chromic salt.1... 

Cobalt Thioarsenate.—With solutions of cobalt salts, sodium orthothioarsenate gives a dark brown precipitate of cobalt pyrothio-arsenate, Co2As2S7, soluble in excess of the reagent.1... 

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... 

Gold Thioarsenates.—Auric Orthothioarsenate, AuAsS4, and auric pyrothioarsenate, Au4(As2S7)3, are obtained as brown precipitates when solutions of gold salts are precipitated respectively with sodium ortho-and pyro-thioarsenates.6 Both salts are soluble in water. 

Iron Thioarsenates.—Both ferrous and ferric salts, when treated with a solution of sodium orthothioarsenate, yield brown precipitates which are soluble in excess of the reagent. The ferric salt is stable in air and may be heated to fusion without decomposition at a higher temperature sulphur is expelled. The ferrous salt decomposes on drying in the air, ferric hydroxide and thioarsenate being formed.6 Ferrous sulphide dissolves in an aqueous solution of an alkah thioarsenate.7... 

Lead Thioarsenates.—The ortho- and pyro-salts are obtained as red and deep brown precipitates when solutions of lead salts are treated respectively with sodium ortho- and pyro-thioarsenates.6 The mineral reniformite (p. 13), occurring in Japan, is probably a thioarsenate of composition Pb3(AsS4)2.2PbS.8... 

Mercuric Orthothioarsenate, Hg3(AsS4)2, is formed as an orange-coloured precipitate by treating mercuric chloride solution with sodium orthothioarsenate.5 It may be dried at 100° C. and sublimed without decomposition. Mercuric pyrothioarsenate is obtained as a dark yellow precipitate when mercuric chloride solution is treated with sodium meta- or pyro-thioarsenate.8 The salt decomposes on heating with loss of arsenic and sulphur. 

Nickel Thioarsenates.—Nickel Orthothioarsenate, Nis(AsS4)2, and nickel pyrothioarsenate, NigAsgS, are formed as dark brown precipitates when aqueous solutions of a nickel salt are precipitated with sodium ortho- and pyro-thioarsenates, respectively.2... 

Platinic Thioarsenate is obtained as a deep yellow precipitate when a solution of hydrochloroplatinic acid is treated with sodium ortho- or meta-thioarsenate.2... 

Silver Thioarsenates.—Silver Ortkothioarsenate, Ag3AsS4, is formed as a dark brown precipitate when an aqueous solution of silver nitrate is treated with sodium orthothioarsenate.1 If, however, silver nitrate is added to a solution of sodium orthothioarsenate, silver orthothioarsenate is not formed but silver sulphide is precipitated and arsenious acid, nitric acid and sodium nitrate are formed in solution.8 The reactions involved probably take the following course 3... 

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... 

Tin Thioarsenates.—By double decomposition with sodium orthothioarsenate, stannous and stannic salts yield, respectively, chestnut-brown and pale yellow precipitates.5... 

Thiosulfuric acid is representative of a general class of acids, called thio acids or sulfo acids, in vhich one or more oxygen atoms of an oxygen add are replaced by sulfur atoms. For example, arsenic penta-sulfide dissolves in a sodium sulfide solution to form the thioarsenate ion, AsS -----, completely analogous to the arsenate ion, AsO ------- ... 

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-... 

As in all liquid-redox processes, part of the sulfur is converted to thiosulfate, although the rate of formation is appreciably lower in the essentially neutral Thylox solution than in more alkaline solutions used in other processes. Hydrogen cyanide, which is absorbed in the absorber, reacts readily with the sulfur formed in the thionizer to yield sodium thiocyanate. Because of these side reactions, the active thioarsenate has to be replenished continuously by addition of arsenic oxide and sodium carbonate. 

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