Sodium thiosulfate, reaction with hydrogen

Lactones in acid-washed samples of modified cotton are not hydrolyzed in methylene blue solution. They may, however, be determined along with free carboxyl groups by steeping the material in a solution containing potassium iodide and iodate, sodium chloride, and an excess of sodium thiosulfate [427,428]. Hydrogen ions from the material liberate iodine according to the reaction... 

Sodium thiosulfate reacts with alkyl halides to form salts of the type RSSOjNa (Bunte salts). Alkyl disulfides may be obtained from these salts by pyrolysis or reaction with iodine or hydrogen peroxide. The yields range from 47% to 6S>%. Cyano and carboxyl groups do not interfere. Benzoylation of sodium thiosulfate produces benzoyl disulfide in 58% yield. ... 

The liquid is circulated at such a rate that a two- to threefold excess of ferric hydroxide over the stoichiometric quantity necessary for the complete reaction with hydrogen sulfide is present. Gollmar (1945) states that the process can be operated with less than the stoichiometric concentration of iron oxide and interprets the function of the iron as a catalytic oxygen carrier. Available historical data from several plants indicate that operation with an excess of iron oxide over the stoichiometric amount was commonly practiced. This excess seems to be required for complete removal of hydrogen sulfide and, also, to minimize thiosulfate formation in the thionizer. For a coal gas plant with a 10 MMsef/day capacity and a hydrogen sulfide removal rate of 400 grains/lOO scf, the chemical requirements are approximately 3,500 Ib/day of sodium carbonate and 2,800 Ib/day of iron. 

A 250-mL, two-necked, round-bottomed flask equipped with a magnetic stirbar, thermometer, and a reflux condenser fitted with a rubber septum and balloon of argon is charged with a solution of methyltrioxorhenium (MTO) (0.013 g, 0.05 mmol, 0.1% mol equiv) in 100 mL of methanol (Note 1). Urea hydrogen peroxide (UHP) (14.3 g, 152 mmol) is added (Notes 1, 2, 3, 4), the flask is cooled in an ice bath, and dibenzylamine (9.7 mL, 50.7 mmol) is then added dropwise via syringe over 10 min (Notes 1, 5). After completion of the addition, the ice bath is removed and the mixture is stirred at room temperature (Note 6). A white precipitate forms after approximately 5 min (Note 7) and the yellow color disappears within 20 min (Note 8). Another four portions of MTO (0.1% mol equiv, 0.013 g each) are added at 30-min intervals (2.5 hr total reaction time). After each addition, the reaction mixture develops a yellow color, which then disappears only after the last addition does the mixture remain pale yellow (Note 9). The reaction flask is cooled in an ice bath and solid sodium thiosulfate pentahydrate (12.6 g, 50.7 mmol) is added in portions over 20 min in order to destroy excess hydrogen peroxide (Note 10). The cooled solution is stirred for 1 hr further, at which point a KI paper assay indicates that the excess oxidant has been completely consumed. The solution is decanted into a 500-mL flask to remove small amounts of undissolved thiosulfate. The solid is washed with 50 mL of MeOH and the methanol extract is added to the reaction solution which is then concentrated under reduced pressure by rotary evaporation. Dichloromethane (250 mL) is added to the residue and the urea is removed by filtration through cotton and celite. Concentration of the filtrate affords 10.3 g (97%) of the nitrone as a yellow solid (Note 11). 

The utihty stream gets started at operating temperature and flow rate. In the following experiments, the utihty stream is heated so as to initiate the reaction. The main and secondary process tines are fed with water at room temperature and with the same flow rate as one of the experiments. Once steady state is reached, operating parameters are recorded. Process tines are then fed with the reactants, hydrogen peroxide and sodium thiosulfate. At steady state, operating parameters are recorded, and a sample of a known mass of reactor products is introduced in the Dewar vessel. Temperature in the Dewar vessel is recorded until equilibrium is reached, that is, until the reaction ends. This calorimetric method is aimed at calculating the conversion rate at the product outlet and thus the conversion rate in the reactor. The latter is also determined by thermal balances between process inlet and outlet of the reactor. Finally, the reactor is rinsed with water. This procedure is repeated for each experiment... 

Selective reduction (e.g., partial reduction of one of two nitro groups) is carried out with an alkali sulfide, such as sodium hydrogen sulfide NaHS ( sodium sulfhy-drate ) or sodium sulfide Na2S, in an aqueous or alcoholic solution. Azo groups are not affected by this method. The reaction converts sodium hydrogen sulfide or sodium sulfide mainly to sodium thiosulfate. 

Dinitrochlorobenzene (95) reacts with pyridine to form 2,4-dinitrophenylpyridinium chloride (103), a reactive intermediate which readily reacts with a variety of nucleophiles. The reaction of (103) with hydrogen sulfide yields 2,2, 4,4 -tetranitrodiphenylsulfide (104), which on nitration-oxidation with fuming nitric acid, yields 2,2, 4,4, 6,6 -hexanitrodiphenylsulfoxide (105). The sulfide (104) is also formed from the reaction of two equivalents of 2,4-dinitrochlorobenzene (95) with sodium thiosulfate or sodium disulfide in aqueous ethanol. ... 

Fig. 5.1.2 Monodispersed BaS04 ellipsoids of 0.14 pm mean size, prepared by homogene-oas precipitation with the slow release of S042- ions through decomposition of thiosulfate ions by hydrogen peroxide in the presence of Ba2+ ions at 20°C. To reduce the mean size, the reaction was carried out with sodium citrate (0.1 mol dm-3). (From Ref. 1.)...

When hydrogen sulfide reacts, with mercuric chloride in neutral or acid solution, or when mercury and sulfur are ground together, black mercuric sulfide is formed. Under certain conditions, this material can be converted into the red modification by the continued action of soluble alkali sulfides. The reaction of mercuric chloride and sodium thiosulfate gives the red form if the ratio of the concentrations is higher than 1 4d The red sulfide is also produced when the substance Hg(SH)NCS is boiled with concentrated ammonium thiocyanate solution or when hydrogen sulfide is conducted into a warm mercuric salt solution in the presence of acetic acid and an excess of ammonium thiocyanate, or thiourea.2,3... 

Reaction of the bis Bunte salt (280), prepared from ethylene dibromide and sodium thiosulfate, with formaldehyde in the presence of hydrogen chloride produces the 1,3-dithiolane (4) (30JCS12). 

Benzoyl disulfide has been obtained by the reaction of benzoyl chloride with hydrogen sulfide, hydrogen disulfide, hydrogen trisulfide, potassium sulfide, sodium disulfide, lead sulfide, sodium hydrosulfite, sodium thiosulfate, sulfhydrylmagnesium bromide, and thiobenzamide. It is also formed by reaction of benzoic anhydride with hydrogen sulfide. The better preparative methods involve the oxidation of thiobenzoic add by means of air,hydrogen peroxide or sulfur monochloride, or of the sodium or potassium salt by means of air, - chlorine, iodine, copper sulfate, - potassium ferricyanide, - or ferric chloride. - ... 

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