Kinetics of the oxidation of dimethyl sulfoxide with aqueous hydrogen peroxide catalyzed by sodium tungstate

1981 ◽  
Vol 59 (4) ◽  
pp. 718-722 ◽  
Author(s):  
Yoshiro Ogata ◽  
Kazushige Tanaka
Keyword(s):  
Hydrogen Peroxide ◽  
Dimethyl Sulfoxide ◽  
Sodium Tungstate ◽  
Catalytic Amount ◽  
Active Oxygen ◽  
Probable Mechanism ◽  
Polarographic Study ◽  
Aqueous Hydrogen Peroxide ◽  
First Order ◽  
Kinetics Of

The oxidation of dimethyl sulfoxide (DMSO) by hydrogen peroxide in the presence of a catalytic amount of sodium tungstate (Na2WO4) has been studied kinetically by means of iodometry of hydrogen peroxide. The reaction is first-order with respect to the substrate and the catalyst, but independent of the concentration of hydrogen peroxide which is present in excess of the catalyst. The polarographic study implies that in solutions two main kinds of peroxytungstic acids (H2WO5 and H2WO8) are formed which contain active oxygen in ratios (active oxygen):(Na2WO4) of 1:1 and 4:1, respectively. The effect of acidity on the oxidation rate and a probable mechanism involving a rate-determining attack of peroxytungstic acids are discussed.

Kinetics of the oxidation of diphenyl sulfide with hydrogen peroxide catalyzed by sodium metavanadate

1982 ◽  
Vol 60 (7) ◽  
pp. 848-852 ◽  
Author(s):  
Yoshiro Ogata ◽  
Kazushige Tanaka
Keyword(s):  
Hydrogen Peroxide ◽  
Rate Constant ◽  
Reaction Rate ◽  
Catalytic Amount ◽  
Probable Mechanism ◽  
Initial Concentration ◽  
Sodium Metavanadate ◽  
Low Concentration ◽  
Diphenyl Sulfide ◽  
Kinetics Of

The oxidation of diphenyl sulfide (Ph2S) by hydrogen peroxide in the presence of a catalytic amount of sodium metavanadate (NaVO3) has been studied kinetically by means of iodometry of hydrogen peroxide. The reaction rate is expressed as: v = k[NaVO3]st[Ph2S]2, when the concentration of catalyst is very low and [Ph2S]0/[H2O2]0 > 2, where []st and []0 mean stoichiometric and initial concentration, respectively. The effective oxidant may consist of polymeric as well as monomeric peroxyvanadate in view of the effect of concentration of catalyst on the rate. The main oxidizing species at low concentration of catalyst seems to be diperoxyvanadate VO5−. The rate constant k2 in v = k2[Ph2S]2 tends to decrease with initial concentration of H2O2, which is present in excess of the catalyst. A probable mechanism for the oxidation is discussed.

scholarly journals Kinetics of the decomposition and the estimation of the stability of 10% aqueous and non-aqueous hydrogen peroxide solutions

2014 ◽  
Vol 27 (4) ◽  
pp. 213-216 ◽  
Author(s):  
Maria Zun ◽  
Dorota Dwornicka ◽  
Katarzyna Wojciechowska ◽  
Katarzyna Swiader ◽  
Regina Kasperek ◽  
...  
Keyword(s):  
Activation Energy ◽  
Hydrogen Peroxide ◽  
Decomposition Rate ◽  
Aqueous Hydrogen Peroxide ◽  
Decomposition Rate Constant ◽  
First Order ◽  
First Order Kinetics ◽  
C 30 ◽  
The Stability ◽  
Kinetics Of

Abstract In this study, the stability of 10% hydrogen peroxide aqueous and non-aqueous solutions with the addition of 6% (w/w) of urea was evaluated. The solutions were stored at 20°C, 30°C and 40°C, and the decomposition of hydrogen peroxide proceeded according to first-order kinetics. With the addition of the urea in the solutions, the decomposition rate constant increased and the activation energy decreased. The temperature of storage also affected the decomposition of substance, however, 10% hydrogen peroxide solutions prepared in PEG-300, and stabilized with the addition of 6% (w/w) of urea had the best constancy.

Preparation of 4-Hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl A Reinvestigation of Methods Using Hydrogen Peroxide in the Presence of Catalysts

1976 ◽  
Vol 31 (10) ◽  
pp. 1376-1378 ◽  
Author(s):  
G. Sosnovsky ◽  
M. Konieczny
Keyword(s):  
Hydrogen Peroxide ◽  
Phosphotungstic Acid ◽  
Sodium Tungstate ◽  
Spin Labeling ◽  
Quantitative Yield ◽  
Hydrogen Peroxide Solution ◽  
Aqueous Hydrogen Peroxide ◽  
Molar Excess

The preparation of the key intermediate for spin labeling, 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (2), was reinvestigated using sodium tungstate or phosphotungstic acid with or without either Trilon or Triton B. A two-fold and a 3.5-fold molar excess of a 30% aqueous hydrogen peroxide solution was used. The oxidation of 4-hydroxy-2,2,6,6-tetramethylpiperidine (1) with a two-fold molar excess of a 30% aqueous hydrogen peroxide solution in the presence of sodium tungstate alone, under vigorous stirring for two hours, is the superior method (A) for the preparation of 2 in virtually quantitative yield.

THE THERMAL DECOMPOSITION OF HYDROGEN PEROXIDE VAPOUR

1945 ◽  
Vol 23b (5) ◽  
pp. 167-182 ◽  
Author(s):  
Bruce E. Baker ◽  
C. Ouellet
Keyword(s):  
Hydrogen Peroxide ◽  
Temperature Coefficient ◽  
Pure Hydrogen ◽  
First Order ◽  
Soda Glass ◽  
Manometric Method ◽  
Apparent Activation Energies ◽  
Reaction Vessels ◽  
First Time ◽  
Kinetics Of

The kinetics of the decomposition of hydrogen peroxide in the vapour state have been studied by a manometric method, with pure hydrogen peroxide at a concentration of about 99.5%. The temperature coefficient of the reaction has been measured for the first time. The pressures ranged from 1 to 2 cm. of mercury and the temperatures from 70° to 200 °C. Pyrex reaction vessels of various sizes and shapes, and also a fused Pyrex and a soda-glass vessel, were used. The reaction was purely heterogeneous, of the first order up to 140 °C. but more complicated at higher temperatures. Identical vessels yielded consistent results. The rates were not affected by air, carbon dioxide, or water vapour, but they varied greatly with the size and shape of the vessel. The reaction was very slow on fused Pyrex and very rapid on soda-glass. In one vessel, the temperature coefficient became negligible above 120 °C. No explosion was detected up to 335 °C. at a pressure of 18 cm. of mercury. The apparent activation energies in various vessels ranged from 13.5 to 18.5 kcal. per mole. A tentative reaction mechanism is suggested.

Kinetics of the Epoxidation of Crotonic Acid by Aqueous Hydrogen Peroxide Catalysed by Sodium Orthovanadatae

2012 ◽  
Vol 28 (3) ◽  
pp. 1475-1478
Author(s):  
J.V. SINGH ◽  
ANUPAM AWASTHI ◽  
DIPTI DIPTI ◽  
ASHISH TOMAR ◽  
DAVENDRA SINGH ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Crotonic Acid ◽  
Aqueous Hydrogen Peroxide ◽  
Kinetics Of

Inactivation Kinetics of Avirulent Bacillus anthracis Spores in Milk with a Combination of Heat and Hydrogen Peroxide

2008 ◽  
Vol 71 (2) ◽  
pp. 333-338 ◽  
Author(s):  
SA XU ◽  
THEODORE P. LABUZA ◽  
FRANCISCO DIEZ-GONZALEZ
Keyword(s):  
Hydrogen Peroxide ◽  
Bacillus Anthracis ◽  
Capillary Tube ◽  
Inactivation Kinetics ◽  
First Order ◽  
Freeze Dried ◽  
Bacillus Anthracis Spores ◽  
The Mean ◽  
D Values ◽  
Kinetics Of

The combined effect of heat and hydrogen peroxide (HP) on the inactivation of avirulent Bacillus anthracis spores (Sterne strain 7702; strain ANR-1, an avirulent Ames derivative lacking the pXO2 plasmid; and strain 9131, a plasmid-less Sterne strain) was evaluated in milk. The study temperature ranged from 90 to 95°C, and the concentration of added HP varied from 0.05 to 0.5%. Decimal reduction times (D-values) were determined using a sealed capillary tube technique. The mean D- and z-values of hydrated freeze-dried spores of all three strains in milk ranged from 550 s at 90C to180s at 94°C and from 8.6 to 9.0°C, respectively. When 0.05% HP was added to the milk, the D-values were decreased at least threefold, and at 0.5% HP the D-values ranged from 1 to 10 s. At 90°C, all three strains had similar D-values when 0.05% HP was added. Increasing the concentration of HP to 0.5% had a greater reducing effect on the D-value for strain 7702 than on the values for strains ANR-1 and 9131. The rate of inactivation of each strain followed first-order reaction kinetics at each temperature-peroxide combination. Equations in the form of D = Constant × (HP concentration)n had R2 values greater than 0.97 for strains ANR-1 and 7702 and of at least 0.7 for strain 9131. This study suggests that a combination of high temperature (from 90 to 95°C) and HP could be used for inactivation of B. anthracis spores in the event of deliberate contamination of milk such that the contaminated milk could be disposed of safely.

scholarly journals Kinetics of Oxidation of Cobalt(III) Complexes ofaAcids by Hydrogen Peroxide in the Presence of Surfactants

2008 ◽  
Vol 5 (1) ◽  
pp. 43-51 ◽  
Author(s):  
Mansur Ahmed ◽  
K. Subramani
Keyword(s):  
Hydrogen Peroxide ◽  
Electron Transfer ◽  
Bond Cleavage ◽  
Micellar Medium ◽  
Hydroxy Acids ◽  
Peroxide Oxidation ◽  
Kinetics Of Oxidation ◽  
First Order ◽  
First Order Kinetics ◽  
Kinetics Of

Hydrogen peroxide oxidation of pentaamminecobalt(III) complexes ofα-hydroxy acids at 35°C in micellar medium has been attempted. In this reaction the rate of oxidation shows first order kinetics each in [cobalt(III)] and [H2O2]. Hydrogen peroxide induced electron transfer in [(NH3)5CoIII-L]2+complexes ofα-hydroxy acids readily yields 100% of cobalt(II) with nearly 100% of C-C bond cleavage products suggesting that it behaves mainly as one equivalent oxidant in micellar medium. With unbound ligand also it behaves only as C-C cleavage agent rather than C-H cleavage agent. With increasing micellar concentration an increase in the rate is observed.

scholarly journals Removal of cyanide in aqueous solution by oxidation with hydrogen peroxide catalyzed by copper oxide

2019 ◽  
Vol 80 (1) ◽  
pp. 126-133
Author(s):  
Hamza Amaouche ◽  
Salima Chergui ◽  
Farid Halet ◽  
Ahmed Réda Yeddou ◽  
Abdelmalek Chergui ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Hydrogen Peroxide ◽  
Copper Oxide ◽  
Copper Oxide Nanoparticles ◽  
Catalyst Stability ◽  
Molar Ratio ◽  
First Order ◽  
Cyanide Removal ◽  
Stability Kinetics ◽  
Kinetics Of

Abstract This work is dedicated to the removal of free cyanide from aqueous solution through oxidation with hydrogen peroxide H2O2 catalyzed by copper oxide nanoparticles. Effects of initial molar ratio [H2O2]0/[CN−]0, catalyst dose, temperature, pH and the catalyst stability on cyanide removal have been investigated. The use of copper oxide has improved the reaction rate showing catalytic activity. The cyanide removal efficiency was increased from 60% to 94% by increasing in the dose of catalyst from 0.5 g/L to 5.0 g/L. Increasing the temperature from 20 °C to 35 °C promotes cyanide removal and the four successive times re-use of catalyst shows good stability. Kinetics of cyanide removal was found to be of pseudo-first-order with respect to cyanide. The rate constants have been determined.

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