DiThionate, barium

The dithionate, [Ir(NH3)5Cl]S206, is formed by treating a cold saturated aqueous solution of the chloride with barium dithionate. It crystallises in long six-sided prisms. 

Barium dithionate (2H2O) [13845-17-5] M 333.5. Crystd from water. 

Salts of Thionic Acids.—A third class of thio salts are those derived from the various thionic acids of which sodium thiosulfate and barium dithionate may be... 

By the addition of barium hydroxide to the solution, a solution of barium dithionate can be obtained which, on treatment with the necessary quantity of sulphuric acid, yields a dilute solution of dithionic acid this can be concentrated to some extent by evaporation at the ordinary temperature, but if the concentration is carried too far, decomposition ensues, with formation of sulphur dioxide and sulphuric acid. If so desired, the barium dithionate itself may be isolated by removing the excess of barium hydroxide with a current of carbon dioxide and then allowing the solution to evaporate until crystallisation occurs. 

The Dithionates or Hyposulphates.—These salts, like the nitrates, are all soluble in water only normal salts are known.4 They may be obtained by neutralising dithionic acid solution with the hydroxide of the base, and also by double decomposition between barium dithionate solution and the sulphate of the base, or between manganese dithionate solution and the hydroxide of the base 5 also by methods on pp. 206-8. 

Hydrazine Ditfaionate, N2H4.H2S2Oa, a polymer of amidosul-phonic acid, may be prepared by the interaction of hydrazine sulphate and barium dithionate. It is obtained as large crystals. On evaporation over sulphuric acid it decomposes with separation of sulphuric anhydride and is converted into a mixture of hydrazine sulphate and secondary hydrazine dithionate, (N3H4)2.H3S306.a... 

Vanadyl Dithionate, VOS2Oe, is prepared by treating a solution of vanadyl sulphate with barium dithionate. It decomposes on standing, with evolution of sulphur dioxide.2... 

S20 K2 Potassium pyrosulfite, 2 165, 166 %-hydrate, 2 165 S20sK2-4S03KH, 2 167 S203Na2 (and + 7H20) Sodium pyrosulfite, 2 162, 164, 165 S20 Ba-2H20 Barium dithionate, 2 170... 

Nickel Oithionate, NiS206.6H20, may be prepared by double decomposition of barium dithionate and nickel sulphate solutions.6 On concentration of the filtered solution, green triclinic prisms separate out. From its solution ammonia precipitates the hexammoniate, NiS206.6NH3. 

Sodium dithionate, Na2S206.1—The dithionate is obtained by the action of sodium carbonate on barium dithionate.2 It is the principal product formed by boiling sodium silver sulphite with water 3... 

Potassium dithionate, K2S206.—The dithionate is prepared by the interaction of barium dithionate and potassium carbonate. It forms hexagonal crystals, of density 4 2-278 at 20° C. The heat of formation from the elements is 415-72 Cal.5 At 16° C. the solubility is 6-06 grams per 100 grams of water.6... 

Rubidium dithiouate, Rb2S206.—The dithionate is formed by the action of rubidium sulphate on barium dithionate.3... 

Caesium dithionate, Cs2S206.—The dithionate is produced by the action of the sulphate on barium dithionate.1 It crystallizes in colourless, hexagonal plates, very soluble in water. 

Ammonium dithionate, (NH4)2S206.—Aqueous solutions of barium dithionate and ammonium sulphate yield on concentration the semi-hydrate in hair-shaped crystals.12 At 16° C. the solubility is 127 grams in 100 grams of water, the solution being accompanied by the absorption of much heat. Heat decomposes the dithionate into ammonium sulphate, water, and sulphur dioxide.13 It combines with an equimolecular proportion of ammonium chloride, yielding rhombic crystals of the formula (NH4)2S206,NH4C1.14... 

Dithionic acid, H2S2O6, can be obtained in quite concentrated aqueons solutions (equation 31) from barium dithionate. The metal dithionates are usually obtained by oxidizing the corresponding sulfite or metathesis. 

Barium dithionate, synthesis SOB Europium amalgam, synthesis 18... 

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