Sodium thiosulfate solution

The hberated iodine is measured spectrometricaHy or titrated with Standard sodium thiosulfate solution (I2 +28203 — 2 1 VS Og following acidification with sulfuric acid buffers are sometimes employed. The method requires measurement of the total gas volume used in the procedure. The presence of other oxidants, such as H2O2 and NO, can interfere with the analysis. The analysis is also technique-sensitive, since it can be affected by a number of variables, including temperature, time, pH, iodide concentration, sampling techniques, etc (140). A detailed procedure is given in Reference 141. 

The hberated iodine is titrated with standard sodium thiosulfate solution. In the thiosulfate method, selenous acid is treated with an excess of standard sodium thiosulfate solution ... 

Sodium thiosulfate, either the anhydrous salt, Na2S202, or the crystalline pentahydrate, is commonly referred to as hypo or crystal hypo. When a concentrated sodium thiosulfate solution (50—60 wt %) is cooled to <48° C, the pentahydrate, containing 63.7% Na2S202, crystallines in monoclinic transparent prisms as shown in the equiUbrium phase diagram (Fig. 1). The monohydrate [55755-19-6] and the heptahydrate [36989-91-0] are also known. 

Aqueous sodium thiosulfate solutions ate neutral. Under neutral or slightly acidic conditions, decomposition produces sulfite and sulfur. In the presence of air, alkaline solutions decompose to sulfate and sulfide. Dilute solutions can be stabilized by small amounts of sodium sulfite, sodium carbonate, or caustic, and by storage at low temperatures away from air and light. Oxidation is inhibited by Hgl2 (10 Ppm) amyl alcohol (1%), chloroform (0.1%), borax (0.05%), or sodium benzoate (0.1%). 

Sodium thiosulfate is a by-product of the manufacture of Sulfur Black and other sulfur dyes (qv), where organic nitro compounds are treated with a solution of sodium polysulfide to give thiosulfate. The dyes ate insoluble and ate recovered by fUtration. The fUtrate is treated with activated carbon and filteted to obtain a sodium thiosulfate solution. After concentration and crystallization, the final product assays ca 96% Na2S202 5H20 (34) (see Dyes AND... 

Analytical and Test Methods. An aqueous solution of sodium thiosulfate forms a white precipitate with hydrochloric acid and evolves sulfur dioxide gas which is detected by its characteristic odor. The white precipitate turns yellow, iadicatiug the presence of sulfur. The addition of ferric chloride to sodium thiosulfate solutions produces a dark violet color which quickly disappears. 

The principal use of photochemical-grade ammonium thiosulfate continues to be in photography, where is dissolves undeveloped silver haUdes from negatives and prints. It reacts considerably faster than sodium thiosulfate, and the fixing solutions can be used about twice as long as sodium thiosulfate solutions the washing period to remove residual thiosulfate is shorter. 

Gold thiosulfate complexes of the form Na2[Au(S202)2] 2H20 [19153-98-1] are prepared by addition of gold trichloride to concentrated sodium thiosulfate solution (89). The gold is completely reduced and some thiosulfate is oxidized to tetrathionate. This complex has been used in the treatment of rheumatoid arthritis. 

The mixture is cooled to room temperature, then filtered. The solvent is removed under reduced pressure, leaving the tribromide (47) as a foam. The foam is mixed with sodium iodide (9.55 g, 0.064 mole) and acetone (74 ml) and heated under reflux in a nitrogen atmosphere for 3.5 hr. The acetone is removed under reduced pressure and the residue is treated with chloroform and aqueous sodium thiosulfate solution. The chloroform layer is separated and washed with sodium thiosulfate solution until it is free from iodine, then dried over magnesium sulfate, filtered and evaporated to dryness under reduced pressure. The crude product (48) is obtained as a brown sohd (4.85 g) which is chromatographed over alumina (122 g, Merck acid-washed). The column is developed with hexane, benzene and ethyl acetate mixtures. The product (3.43 g) is eluted by benzene and benzene-ethyl acetate (10 1). Recrystallization from acetone yields purified 3jS-acetoxy-pregna-5,14,16-trien-20-one (48), 3.25 g, mp 158-159° 309 m/ (e 10,700). 

Photographers hypo (sodium thiosulfate solution) and ordinary hypo (sodium hypochlorite solution)... 

A mixture of 17 g of the methiodide and 32 ml of a 40 % aqueous potassium hydroxide solution is heated with stirring in a flask fitted with a condenser. The heating bath should be kept at 125-130°, and the heating should be continued for 5 hours. The cooled reaction mixture is then diluted with 30 ml of water and washed twice with 25-ml portions of ether. The aqueous layer is cautiously acidified in the cold with concentrated hydrochloric acid to a pH of about 2 and then extracted five times with 25-ml portions of ether. The combined extracts are washed twice with 10% sodium thiosulfate solution and are dried (magnesium sulfate). Removal of the solvent followed by distillation affords about 3 g of 4-cyclooctene-l-carboxylic acid, bp 125-12671-1 mm. The product may solidify and may be recrystallized by dissolution in a minimum amount of pentane followed by cooling in a Dry-Ice bath. After rapid filtration, the collected solid has mp 34-35°. 

The residue is dissolved in ether and the solution is washed with sodium chloride solution and then with a little sodium thiosulfate solution. The ethereal solution is dried over sodium sulfate and ether removed by distillation. A yield of 108 parts of 3,5,5-trimethyl-oxazolidine-2,4-dione is obtained having a melting point of 45° to 46°C with slight softening at 43°C. This represents a 75% theory yield on the ethyl o-hydroxy-iso-butyrate taken. The product may be further purified by dissolving the minimum quantity of dry ether and cooling to -10°C. The product so obtained melts sharply at 45.5° to 46.5°C, according to U.S. Patent 2,559,011. 

The benzoylperoxide used was analyzed by dissolving r g. in 25 cc. of dry ether and adding 2 cc. of 5 per cent sodium ethylate solution, keeping the temperature below — 50. The ether solution was extracted with exactly 100 cc. of cold water and an aliquot part of the aqueous extract taken. To this was added 2 cc. of 5 per cent potassium iodide and 2 cc. of dilute hydrochloric acid and the liberated iodine was titrated with 0.1 N sodium thiosulfate solution. The peroxide analyzed 90 per cent pure. 

Upon addition of sodium thiosulfate solution, the AgBr precipitate dissolves, because S2 03 forms a very strong complex with Ag. This ligand is capable of dissolving AgBr ... 

Recendy, ID quantum dots of gallium selenide with average diameter 8-10 nm, connected in the form of chains of average length 50-60 nm, were synthesized on rro substrates by cathodic electrodeposition from acidic aqueous solutions of gallium(III) nitrate and selenious acid [186], The structural analysis from XRD patterns revealed the formation of Ga2Se3/GaSe composition. The films were found to be photoactive in aqueous sodium thiosulfate solution and showed p-type conductivity. 

Absorb in an impinger containing a standardized solution of iodine and potassium iodide titrate with standard sodium thiosulfate solution. Iodometric titration No data NR EPA 1978... 

A mercury manometer used with ammonia became blocked by deposition of a grey-brown solid, which exploded dining attempts to remove it mechanically or on heating. The solid appeared to be a dehydration product of Millon s base and was freely soluble in sodium thiosulfate solution. This method of cleaning is probably safer than others, but the use of mercury manometers with ammonia should be avoided as intrinsically unsafe [1,2]. Although pure dry ammonia and mercury do not react even under pressure at 340 kbar and 200° C, the presence of traces of water leads to the formation of an explosive compound, which may explode during depressurisation of the system [3], Explosions in mercury-ammonia systems had been reported previously [4,5],... 

Soliman and Belal investigated argentimetric (67,68) and mercurimetric (69) methods. Hydralazine precipitates silver from ammoniacal silver nitrate solution. The silver is dissolved with hot nitric acid and titrated with ammonium thiocyanate solution. Alternatively, mercury is precipitated from alkaline potassium mercuric iodide solution. The precipitated mercury is dissolved by adding excess standard iodine solution. The excess iodine is back-titrated with sodium thiosulfate solution after acidifying with acetic acid. 

A sample of iodine-128 was produced in a Szilard-Chalmers reaction by irradiating a sample of ethyl iodide in a neutron source. The radio-iodine was extracted with sodium thiosulfate solution and then counted in a Geiger counter at various time Intervals. Use the tabulated data of t in minutes against C counts/min to find the rate equation and the half time. 

Ingestion Give victim 1 percent of sodium thiosulfate solution (or plain water) immediately by mouth and induce vomiting repeat as needed until all vomit fluid is clear. Never give anything by mouth to an unconscious victim give oxygen, and seek medical help immediately. 

N Sodium thiosulfate solution is prepared daily by dilution of stock solution of known concentration. 

Perhaps this may be considered in relation to the suggestion of Kellermeyer et al. (K5) that the drugs involved are transformed in vivo to redox intermediates. Furthermore, the reducing capacity of RBC was shown to be a function of GSH content. Reduction of this capacity by intravenous infusion of sodium thiosulfate solution reflects changes in the intracellular oxidation-reduction system of glutathione, the oxidized form being favored (Cl, S9). 

If 20. mL of the sodium hypochlorite solution was at 25.0°C and 30. mL of the sodium thiosulfate solution was initially at 35.0°C before they were mixed, and after they were mixed together the final temperature was 34.0 °C, what would be the actual final temperature of the mixture ... 

Available from K K Laboratories or may be prepared in 89% yield by the following procedure. To a solution of 393 g. (2.63 moles) of sodium iodide in 1 1. of reagent grade acetone is added 394 g. (2.50 moles) of l-bromo-3 chloropropane (Aldrich Chemical Co.). After stirring 2 hours at room temperature, the mixture is filtered, the sodium bromide is washed with acetone, and the acetone is evaporated at reduced pressure. A dark iodine color is present along with some solid sodium salts. The oil is dissolved in ether, and the solution is washed with a 10% aqueous sodium thiosulfate solution. The ethereal layer is separated, dried over anhydrous sodium sulfate, and evaporated at reduced pressure to yield 454 g. of an oil that can be used without further purification. 

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