Comment: On the Decomposition of Aqueous Sodium Dithionite

1971 ◽  
Vol 49 (7) ◽  
pp. 1139-1140 ◽  
Author(s):  
L. Burlamacchi ◽  
G. Guarini ◽  
E. Tiezzi
Keyword(s):  
Aqueous Solution ◽  
Sodium Dithionite ◽  
Aqueous Sodium ◽  
Work Done ◽  
Dithionite Ion

The mechanism proposed by M. Wayman and W. J. Lem for the decomposition of dithionite ion in aqueous solution is reconsidered in the light of previous work done by the authors.

Rate of reaction of dithionite ion with oxygen in aqueous solution

1964 ◽  
Vol 19 (3) ◽  
pp. 522-525 ◽  
Author(s):  
J. A. Morello ◽  
Margot R. Craw ◽  
H. P. Constantine ◽  
R. E. Forster
Keyword(s):  
Aqueous Solution ◽  
Reaction Rate ◽  
Initial Rate ◽  
Sodium Dithionite ◽  
Zero Order ◽  
Flowing Liquid ◽  
First Order ◽  
Rate Of Reaction ◽  
Dithionite Ion ◽  
Kinetics Of

The rate of removal of oxygen from aqueous solution by sodium dithionite in 0.1 m sodium hydroxide was studied in a rapid-reaction apparatus using a membrane-covered polarographic cell to determine Po2 in the flowing liquid. The measurements were made at 37 C, so that the data would be applicable in studies of the kinetics of oxyhemoglobin in blood. The initial concentrations in the mixed reacting solution were between 8 x 10-5 m and 47.5 x 10-5 m for dithionite, and either 10 x 10-5 m or 47.8 x 10-5 m for O2. The reaction over the first 40 msec was found to be first order with respect to dithionite and zero order with respect to molecular oxygen. The initial rate constant was 42.5 ± sd 3.6 sec-1. oxygen reduction by dithionite; hemoglobin; deoxygenation rate; dithionite-oxygen reaction rate Submitted on June 17, 1963

DETERMINATION OF TRACE AMOUNTS OF SILVER IN GALENA ORES

1960 ◽  
Vol 38 (9) ◽  
pp. 1488-1494 ◽  
Author(s):  
E. J. Bounsall ◽  
W. A. E. McBryde
Keyword(s):  
Aqueous Solution ◽  
Nitric Acid ◽  
Sodium Chloride ◽  
Hydrochloric Acid ◽  
Chloride Solution ◽  
Sodium Chloride Solution ◽  
Silver Content ◽  
Aqueous Sodium Chloride Solution ◽  
Aqueous Sodium

An analytical method is described for the determination of microgram amounts of silver in galena ores, based on the "reversion" of silver dithizonate. Silver is separated from relatively large amounts of lead by extraction as dithizonate into chloroform from an aqueous 1:99 nitric acid solution. Separation from mercury, which is also extracted under these conditions and would, if present, interfere in the analysis, is achieved by reverting the dithizonate solution with a 5% aqueous sodium chloride solution which is also 0.015 molar in hydrochloric acid. Following dilution of this aqueous solution and adjustment of pH, silver is again extracted into chloroform as the dithizonate, and determined absorptiometrically. Analyses of a number of galena ore samples showed a precision of within 3% for a silver content ranging from 0.03 to 0.4%.Some other methods for isolating silver from these samples, which were tried but found unsatisfactory, are discussed.

scholarly journals Nitrogenase of Klebsiella pneumoniae. Kinetic studies on the Fe protein involving reduction by sodium dithionite, the binding of MgADP and a conformation change that alters the reactivity of the 4Fe-4S centre

1987 ◽  
Vol 246 (2) ◽  
pp. 455-465 ◽  
Author(s):  
G A Ashby ◽  
R N F Thorneley
Keyword(s):  
Klebsiella Pneumoniae ◽  
Rate Constants ◽  
Protein Conformation ◽  
Kinetic Studies ◽  
Sodium Dithionite ◽  
Conformation Change ◽  
Fe Protein ◽  
Redox Active ◽  
Dithionite Ion ◽  
Kinetics Of

The kinetics of reduction of indigocarmine-dye-oxidized Fe protein of nitrogenase from Klebsiella pneumoniae (Kp2ox) by sodium dithionite in the presence and absence of MgADP were studied by stopped-flow spectrophotometry at 23 degrees C and at pH 7.4. Highly co-operative binding of 2MgADP (composite K greater than 4 × 10(10) M-2) to Kp2ox induced a rapid conformation change which caused the redox-active 4Fe-4S centre to be reduced by SO2-.(formed by the predissociation of dithionite ion) with k = 3 × 10(6) M-1.s-1. This rate constant is at least 30 times lower than that for the reduction of free Kp2ox (k greater than 10(8) M-1.s-1). Two mechanisms have been considered and limits obtained for the rate constants for MgADP binding/dissociation and a protein conformation change. Both mechanisms give rate constants (e.g. MgADP binding 3 × 10(5) less than k less than 3 × 10(6) M-1.s-1 and protein conformation change 6 × 10(2) less than k less than 6 × 10(3) s-1) that are similar to those reported for creatine kinase (EC 2.7.3.2). The kinetics also show that in the catalytic cycle of nitrogenase with sodium dithionite as reductant replacement of 2MgADP by 2MgATP occurs on reduced and not oxidized Kp2. Although the Kp2ox was reduced stoichiometrically by SO2-. and bound two equivalents of MgADP with complete conversion into the less-reactive conformation, it was only 45% active with respect to its ability to effect MgATP-dependent electron transfer to the MoFe protein.

Der Einfluß von Sulfoxylaten auf die Photoleitfähigkeit chemisch hergestellter Bleisulfidschichten / The Influence of Sulfoxylates on the Photoconductivity of Chemically Deposited Lead Sulfide Layers

1971 ◽  
Vol 26 (1) ◽  
pp. 8-11 ◽  
Author(s):  
O. A. Kunze ◽  
O. G. Malan ◽  
P. A. Büger ◽  
W. Fink
Keyword(s):  
Aqueous Solution ◽  
Partial Oxidation ◽  
Lead Sulfide ◽  
Sodium Dithionite ◽  
Pronounced Effect ◽  
Intermediate Oxidation

In addition to the procedure of partial oxidation of lead sulfide layers in order to increase their photoconductivity it was found that reduction may have a similar effect.When used as additives to the conventional thiourea-plumbite solution, the compounds aminoiminomethanesulfinic acid (1), rongalite or sodium dithionite, which all may form sulfoxylate in aqueous solution, enhance the photoconductivity of the deposited layers.Addition of H2O2 or PbO2 has a similar, less pronounced effect, which may also be ascribed to the intermediate oxidation of thiourea to 1.

Methods of preparation of sulfanes

1968 ◽  
Vol 46 (14) ◽  
pp. 2341-2346 ◽  
Author(s):  
E. Muller ◽  
J. B. Hyne
Keyword(s):  
Aqueous Solution ◽  
Proton Transfer ◽  
Sulfur Content ◽  
Reactive Intermediates ◽  
Molar Ratio ◽  
Crude Oils ◽  
Large Excess ◽  
Aqueous Sodium ◽  
Wide Range ◽  
Sodium Polysulfide

Sulfane crude oils obtained by acidification of aqueous sodium polysulfide solutions vary little in composition with varying sulfur content of the solution. Evidence presented suggests that the distribution of the sulfanes in such crude oils reflects the equilibrated distribution of the various polysulfide anions in the aqueous solution before acidification. The sulfane distribution in mixtures obtained by reaction of liquid H2S with Br2, SCl2, and S2Cl2 respectively varies over a wide range, depending on the molar ratio of the reactants. Liquid H2S reacts with Br2 or SCl2 to yield essentially the same products. These reactions, however, differ in the nature of their intermediates. By using a large excess of liquid H2S, H2S3 was directly synthesized in over 90% purity. Liquid H2S reacts with S2Cl2 to yield H2S4 in over 90% purity. Gaseous HCl catalyzes the reaction of H2S with the chlorosulfanes and a mechanism is suggested involving HCl as a proton transfer agent in the formation of the reactive intermediates.

Na3V2O2x(PO4)2F3−2x: a stable and high-voltage cathode material for aqueous sodium-ion batteries with high energy density

2015 ◽  
Vol 3 (12) ◽  
pp. 6271-6275 ◽  
Author(s):  
P. Ramesh Kumar ◽  
Young Hwa Jung ◽  
Chek Hai Lim ◽  
Do Kyung Kim
Keyword(s):  
Aqueous Solution ◽  
Energy Density ◽  
Cathode Material ◽  
High Voltage ◽  
High Energy ◽  
Sodium Ion ◽  
High Energy Density ◽  
Sodium Ion Batteries ◽  
Aqueous Sodium ◽  
First Time

The reversible electrochemical activity of the Na3V2O2x(PO4)2F3−2x compound in an aqueous solution is reported for the first time.

L'o-nitrobenzylidènediméthylsulfuranne: synthèse, réactivité

1985 ◽  
Vol 63 (11) ◽  
pp. 2958-2960
Author(s):  
Yannick Le Stanc ◽  
Maurice Le Corre
Keyword(s):  
Aqueous Solution ◽  
Sodium Hydroxide ◽  
Aqueous Sodium Hydroxide ◽  
Two Phase ◽  
Aqueous Sodium ◽  
Nitrobenzyl Alcohol

In aqueous solution, o-nitrobenzyldimethylsulfonium bromide and the corresponding ylid give, depending upon the conditions, o-nitrobenzyl alcohol, o-nitrobenzylsulfide, or methyl o-hydroxymethylbenzyl sulfide. The o-nitrophenyloxiranes may be obtained by the reaction of nitrobenzylidenedimethylsulfurane with aldehydes in a two-phase aqueous sodium hydroxide/dichloromethane system.

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