Barium thiosulfate

X-ray crystallographic analysis of the sodium thiosulfate pentahydrate [10102-17-7] crystal indicates a tetrahedral stmcture for the thiosulfate ion. The S—S bond distance is 197 pm the S—O bond distance is 148 pm (5). Neutron diffraction of a barium thiosulfate monohydrate [7787-40-8] crystal confirms the tetrahedral stmcture and bond distances for the thiosulfate ion (6). 

Many other metal thiosulfates, eg, magnesium thiosulfate [10124-53-5] and its hexahydrate [13446-30-5] have been prepared on a laboratory scale, but with the exception of the calcium, barium [35112-53-9] and lead compounds, these are of Httle commercial or technical interest. Although thaHous [13453-46-8] silver, lead, and barium thiosulfates are only slightly soluble, other metal thiosulfates are usually soluble in water. The lead and silver salts are anhydrous the others usually form more than one hydrate. Aqueous solutions are stable at low temperatures and in the absence of air. The chemical properties are those of thiosulfates and the respective cation. 

Thiosulfates are generally prepared by treating aqueous solutions of either calcium or barium thiosulfate with the corresponding carbonate or sulfate of the desired metal. The insoluble calcium or barium sulfates or carbonates are filtered and the thiosulfate recovered from the filtrate by vacuum evaporation. 

Barium thiosulfate (BaS O ) is mainly used in explosives, matches, varnishes, and photography. 

To a solution of 35. Og of barium chloride 2-hydrate in 100ml of distilled water are added 35.5g of solid sodium thiosulfate 5-hydrate. The mixture is stirred until the latter dissolves. The barium thiosulfate 1-hydrate is filtered by suction, washed with three 20-ml portions of ice-cold water, and. then with a similar quantity of 95% alcohol. It is dried in air. 

To a solution of 70.0g of cobalt (II) sulfate 7-hydrate in 200 ml of water warmed to 50°C are added 0 .Og of barium thiosulfate 1-hydrate. The mixture is stirred at 50°C until the barium sulfate settles out completely and it is then... 

This compound may be prepared in solution by dissolving 4.5g of nickel sulfate 7-hydrate in 25ml of water and adding 5g of barium thiosulfate monohydrate. 

A suspension of 4 g of barium thiosulfate monohydrate (No. 37) in 100ml of water is mixed with 5g of carbonato-diethylenediaminecobalt (III) bromide (No. 127 b) and the mixture is stirred mechanically for one hour on the steam bath. The barium carbonate is filtered off and the red filtrate evaporated to dryness in an oven at 45-60° C over a period of two to three days. 

Decolorized a colorless solution of tetrathionate ions is formed White precipitate of barium thiosulfate White precipitate of silver thiosulfate... 

AI4C3 aluminum carbide 1299-86-1 25.00 2.3600 1 471 BaH204S2 barium thiosulfate monohydrate 7787-40-8 25.00 3.5000 1... 

Iodine solutions can be standardized against anhydrous sodium thiosulfate or barium thiosulfate monohydrate, both of which are available commercially. The reaction between iodine and sodium thiosulfate is discussed in detail in Section 20B-2. Often, solutions of iodine are standardized against solutions of sodium thiosulfate that have in turn been standardized against potassium iodate or potassium dichromate (.see Section 20B-2). Table 20-6 summarizes methods that use iodine as an oxidizing agent. 

Barium thiosulfate monohydrate BaSj03- HjO 7787-40-8 267.471 wh cry powder dec 3.6 0.2 lEtOH... 

Precautions An allergen. Combustible when heated. Synonyms balsam peru oil Peruvian balsam Barium Thiosulfate... 

Aqueous forms, with 8263, white barium thiosulfate, Ba8203, slightly soluble in H2O. The corresponding strontium salt is formed only from a fairly concentrated solution, and the calcium salt is readily soluble in H2O (distinction from 803 ). The Mn " and Zn " ions give no precipitate with 8203 " (distinction from 8 ). 

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