14383-50-7Relevant academic research and scientific papers
Kinetics and mechanism of the decomposition of tetrathionate ion in alkaline medium
Varga, Denes,Horvath, Attila K.
, p. 7654 - 7661 (2008/10/09)
The kinetics of the alkaline decomposition of tetrathionate has been studied spectrophotometrically in the pH range of 9.2-12.2 using both phosphate/hydrogen phosphate and carbonate/hydrogen carbonate as buffer systems and by adjusting the ionic strength to I = 0.5 M with sodium perchlorate at T = 25.0 ± 0.1°C. Matrix rank analysis of the spectra recorded between 265 and 330 nm shows the presence of three independent absorbing species. Besides tetrathionate, thiosulfate and trithionate are identified as absorbing products of the decomposition, but sulfite and a trace amount of sulfate are also formed during the alkaline degradation process. With pentathionate, sulfoxylic acid (S(OH)2), S2O3OH-, and S3O3OH- as key intermediates, a 10-step kinetic model is proposed with six fitted kinetic parameters to take all the important characteristics of the experimental curves into account. On the basis of the stoichiometric measurements and the model proposed, it is also enlightened that the product distribution of the reaction continuously varies with pH; thus the kinetic traces cannot be evaluated by assuming a single stoichiometry in contrast to recent studies. Buffer dependence of the decomposition is also discussed.
The Molecular Composition of Hydrophilic Sulfur Sols Prepared by Acid Decomposition of Thiosulfate
Steudel, Ralf,Goebel, Thomas,Holdt, Gabriele
, p. 203 - 218 (2007/10/02)
Hydrophilic sulfur sols prepared from sodium thiosulfate and concentrated sulfuric acid and purified by repeated NaCl precipitation and peptization in water have been studied by chemical analysis, vibrational spectroscopy, ion-pair chromatography and reversed-phase HPLC.The composition of the sol is Na1.64S28.6O6*5.9/nSn*1.0NaCl.The elemental sulfur Sn (n = 6-14; mainly S8) accounts for 17 percent the total sulfur; 83 percent of the S are present as long-chain polythionates which form micelles in which the Sn molecules are dissolved.On aging of the sol at 20 deg C the polythionate micelles decompose to give water-soluble short-chain polythionates and elemental sulfur which precipitates from the solution.The micelle structure of hydrophilic sulfur sols may serve as a model for the so-called sulfur globules (S0) formed intra- or extracellularly by many sulfur bacteria which oxidize reduced sulfur compounds to S0. - Infrared and Raman spectra of K2SmO6 (m = 3-6) are reported.The photodecomposition of aqueous tetrathionate yields sulfite, thiosulfate, and polythionates with up to 9 sulfur atoms. - Keywords: Sulfur Sol, Polythionates, Elemental Sulfur, Thiosulfate Decomposition, Sulfur Bacteria
Photocatalytic Oxidation of Sulfur on the Doped TiO2 Catalysts
Matsumoto, Yasumichi,Yamaguchi, Yasuhide,Sato, Ei-ichi
, p. 1255 - 1258 (2007/10/02)
TiO2 (anatase) doped with various elements was used as the photocatalyst in the production of sulfuric acid from sulfur in water into which O2 was bubbled.The catalysts doped with typical elements having one and two valencies showed high catalytic activit
Catalytic Activity of Copper-containing KB-4 Ion Exchangers Towards the Oxidation of Sodium Sulphide by Molecular Oxygen in Aqueous Solution
Shi, Fung Ti,Astanina, A. N.,Bystrov, T. S.,Volkov, V. I.,Kopylov, V. D.,et al.
, p. 1109 - 1111 (2007/10/02)
The co-ordination complexes of Cu(II) with the KB-4 carboxylic acid ion exchanger have been prepared and studied by chemical, i.r., and ESR spectral methods.In the Cu(II) concentration range 0.05-1.34 mg*equiv g-1 the composition of the co-ordination complexes does not change: Cu(II)(RCCO-)2(RCOOH)2(H2O)2, i.e. four carboxyl groups in a square coplanar configuration, and two water molecules at the apices of the octahedron.The relationship between the composition of the active centre and the catalytic activity of the resin towards the oxidation of sodium sulphide by molecular oxygen has been established.
