The kinetics of elementary reactions involving the oxides of sulphur II. Chemical reactions in the sulphur dioxide afterglow

1966 ◽  
Vol 295 (1443) ◽  
pp. 363-379 ◽  
Keyword(s):  
Excited States ◽  
Sulphur Dioxide ◽  
Kinetic Studies ◽  
Absolute Intensity ◽  
Third Order ◽  
Elementary Reactions ◽  
The Third ◽  
Dominant Process ◽  
Recombination Reactions ◽  
Kinetics Of

The main recombination reactions in the sulphur dioxide afterglow are shown to be O + SO 2 + M = SO 3 + M (1) and O + SO + M = SO 2 + M , (2) with rate constants of (4·7 ± 0·8) x 10 15 and (3·2 ± 0·4) x 10 17 cm 6 mole -2 s -1 respectively at 300°K for M = Ar. Reaction (2) is the dominant process removing sulphur monoxide (SO) which is otherwise remarkably unreactive. The absolute intensity of the sulphur dioxide afterglow is found to be I = 1·5 x 10 8 [O] [SO] cm 3 mole -1 s -1 for argon carriers at pressures between 0·25 an d 3·0 mmHg. The afterglow emission comes from three excited states of SO 2 . Spectroscopic and kinetic studies show that these are populated subsequent to or by the third order combination reaction (2). Excited SO 2 is removed mainly by electronic quenching.

scholarly journals Kinetic Studies of Fibrinogen in Pregnant Rabbits

1977 ◽  
Author(s):  
R.-M. Moeller ◽  
I. Mahn ◽  
G. Müller-Berqhaus
Keyword(s):  
Kinetic Studies ◽  
Distribution Volume ◽  
Fractional Catabolic Rate ◽  
Third Trimester ◽  
The Third ◽  
Quantitative Measurements ◽  
Catabolic Rate ◽  
Average Acceleration ◽  
The Mean ◽  
Kinetics Of

During gestation increased concentrations of fibrin (ogen)derivatives are observed indicative of intravascular action of thrombin. The aim of this study was to elucidate the kinetics of fibrinogen during gestation. The elimination of homologous 1-125-fibrinogen was studied in 14 pregnant rabbits during the first as well as during the third trimesters of gestation. Control studies were performed with 10 non-pregnant rabbits.The mean distribution volume of labeled fibrinogen did not significantly differ between pregnant and non-pregnant rabbits. During the third trimester pregnant rabbits demonstrated a pronounced shortening of T 1/2 of labeled fibrinogen from a mean of 55.3 hr during the first to a mean of 29.7 hr during the third trimester. The experiments showed a significant increase in the fractional catabolic rate from 45.0 to 69.9% per day in the course of gestation. The shortening of T 1/2 of labeled fibrinogen correlated to the number of fetusses per litter.This study indicates an average acceleration of the fibrinogen turnover during gestation of about 50%. These direct quantitative measurements demonstrate that fibrinogen catabolism is pronouncedly accelerated during pregnancy.

scholarly journals The kinetics of the combination of hydrogen and oxygen

1928 ◽  
Vol 118 (779) ◽  
pp. 170-183 ◽  
Keyword(s):  
Gas Phase ◽  
Constant Temperature ◽  
Catalytic Reaction ◽  
Chemical Change ◽  
Third Order ◽  
Fundamental Interest ◽  
The Third ◽  
Series Of Experiments ◽  
Kinetics Of

Although there are few gaseous reactions of more fundamental interest than the union of hydrogen and oxygen, it can hardly be said that the kinetics of this combination are at all completely understood. Many investigations have been made of the catalytic reaction which occurs in contact with various surfaces, and of the phenomena accompanying the production of flame or explosion in the gas. Little is known about the conditions governing the rate of the actual chemical change in the gas phase, because although flames and explosions depend very much upon these they are determined by a great many other factors as well. In 1899 Bodenstein, following up some work initiated by Victor Meyer, made a long series of experiments by streaming mixtures of the two gases through porcelain vessels, heated to a constant temperature, and then analysing the products. He came to the conclusion that the reaction is of the third order, following the equation d [H 2 O]/ dt = k [H 2 ] 2 [O 2 ]. Since the rate of combination was very different in different vessels, he inferred that the reaction was taking place almost entirely on the surface of the vessel.

Rates of elementary processes in the chain reaction between hydrogen and oxygen II. Kinetics of the reaction of hydrogen atoms with molecular oxygen

1963 ◽  
Vol 275 (1363) ◽  
pp. 559-574 ◽  
Keyword(s):  
Molecular Oxygen ◽  
Kinetic Studies ◽  
Negative Temperature ◽  
Product Analysis ◽  
Hydrogen Atoms ◽  
The Third ◽  
Rate Determining Step ◽  
A Value ◽  
Explosion Limit ◽  
Kinetics Of

The addition of molecular oxygen was found to increase the rate of rem oval of hydrogen atoms in a flow system at and below room temperature. Kinetic studies of this process using argon carrier showed that the rate-determining step is the third-order reaction H + O2 + Ar = HO 2 + Ar. (2) Atomic oxygen in small concentrations is produced in the system. Product analysis and measurements of oxygen atom concentrations indicated that the principal reactions removing HO 2 under these conditions are H+HO 2 = H 2 +O 2 , (12a) H+HO 2 = OH+OH, (12b) H+HO 2 = H 2 O+O 2 , (12c) A value for k 2 of 2.2 x 10 -32 cm 6 molecule -2 s -1 was determined at 293 °K. Reaction (2) was found to have a small negative temperature coefficient. These data and values of k 2 from explosion limit studies can be represented by the expression k 2 = 1.3 x 10 -33 exp (+ 1600 + 700/ RT ) cm 6 molecule -2 s -1 in the range 250 to 800 °K. The third-body efficiencies in reaction (2) at 293 °K of He and H 2 O relative to Ar are similar to those obtained from data on the second explosion limit at higher temperatures.

KINETICS AND MECHANISMS OF THE THERMAL DECOMPOSITION OF ACETALDEHYDE: I. THE UNINHIBITED REACTION

1964 ◽  
Vol 42 (8) ◽  
pp. 1851-1860 ◽  
Author(s):  
M. Eusuf ◽  
K. J. Laidler
Keyword(s):  
Order Reaction ◽  
Second Order ◽  
Small Extent ◽  
Kinetic Behavior ◽  
Third Order ◽  
The Third ◽  
Rate Of Reaction ◽  
Ethane Formation ◽  
Kinetics Of ◽  
Initial Process

The kinetics of the uninhibited decomposition of acetaldehyde have been reexamined. The initial rates of the decomposition of pure acetaldehyde show strict three-halves-order dependence at temperatures from 480 to 525 °C, and the activation energy is 47.6 kcal per mole. Foreign gases, which decrease the rate of reaction, cause a significant increase in order. The rate of ethane formation is second order in acetaldehyde, and Trenwith has found the hydrogen formation to be second order in acetaldehyde. The results are shown to be consistent only with a mechanism involving second-order initiation and the third-order reaction 2CH3 + M → C2H6 + M as the terminating step. The rate of the initiation process is increased only to a small extent by the addition of inert foreign gases; it is suggested that the initial process may be CH3CHO + CH3CHO → CH3CHOH + CH3CO, with a subsequent breakdown of CH3CHOH into CH3CHO + H. The mechanism is shown to account for the overall kinetic behavior and for the formation of the minor products.

Kinetics on Oxidation of Odor Contaminant-Dimethyl Trisulfide by Potassium Ferrate in Drinking Water

2011 ◽  
Vol 255-260 ◽  
pp. 2987-2993 ◽  
Author(s):  
Shi Fei Hu ◽  
Xiao Yan Ma ◽  
Hong Yu Wang ◽  
Jun Li ◽  
Jing Huang ◽  
...  
Keyword(s):  
Drinking Water ◽  
Reaction Rate ◽  
Reaction Rate Constant ◽  
Potassium Ferrate ◽  
Third Order ◽  
Dimethyl Trisulfide ◽  
The Third ◽  
Batch Tests ◽  
Unpleasant Odor ◽  
Kinetics Of

Metabolites of alga that will induce disgusting odor into drinking water such as geosmin, 2-methylisoborneol and dimethyl trisulfide, etc. attracted more and more scholar’s attention recently. Dimethyl trisulfide was newly noticed to be criminal of some water supply accidents of unpleasant odor in our country and was found removed effectively by oxidation agents. Batch tests were carried out in this research to investigate reaction kinetics of dimethyl trisulfide oxidized by potassium ferrate in water. Results showed that dimethyl trisulfide can be removed by potassium ferrate and the rate of decomposition followed third-order kinetics, the third-order reaction rate constant k= 6.57×10L/ (s·mg).

Kinetics and Temperature Dependence of the Hydration of NO+ in the Gas Phase

1973 ◽  
Vol 51 (3) ◽  
pp. 456-461 ◽  
Author(s):  
Margaret A. French ◽  
L. P. Hills ◽  
P. Kebarle
Keyword(s):  
Temperature Dependence ◽  
Gas Phase ◽  
Rate Constants ◽  
Room Temperature ◽  
Transfer Reaction ◽  
Negative Temperature ◽  
Ion Source ◽  
Third Order ◽  
The Third ◽  
Kinetics Of

The kinetics of the atmospherically important hydration sequence: NO+(H2O)n−1 + H2O = NO+(H2O)n and the transfer reaction NO+(H2O)n + H2O = HNO2 + H+(H2O)n were examined in nitrogen containing small quantities of NO and H2O with a pulsed high pressure ion source mass spectrometer. The room temperature mechanism and rate constants were found to be in agreement with earlier work in other laboratories. The temperature dependence of the reaction was examined for the range 27–157 °C. The transfer reaction does not occur at higher temperatures so that the NO+ hydration equilibria for n = 1 and 2 could be measured leading to ΔH1,0 = 18.5 and ΔH2,1 = 16.1 kcal/mol. The third order forward clustering rate constants were found to have negative temperature coefficients.

scholarly journals Higher Order Perturbation Corrections of Rotating Excited States in the Standard SU(3) Skyrme Model to Baryon Mass Spectrum

1997 ◽  
Vol 12 (05) ◽  
pp. 873-890 ◽  
Author(s):  
Jin-Ping Li ◽  
Mu-Lin Yan ◽  
Rong-Hua Yu
Keyword(s):  
Experimental Data ◽  
Mass Spectrum ◽  
Excited States ◽  
Higher Order ◽  
Skyrme Model ◽  
Order Perturbation ◽  
Third Order ◽  
The Third ◽  
Baryon Mass ◽  
Higher Order Corrections

The higher order corrections of SU(3) rotating excited states to the Gell-Mann–Okubo Relations (or GOR) are presented in the standard SU(3) Skyrme model. The Improved GOR (or IGOR) are obtained. The results show the IGOR for decuplet up to the third order and for octet up to the second order are much compatible with the experimental data. But things become quite inadequate for the octet to the third order. In order to overcome the inadequacy, a heuristic discussion is presented. The properties of SU(3) rotating excited states 27-let (with spin [Formula: see text] or [Formula: see text]), 10*-let (with spin [Formula: see text]) and 35-let (with spin [Formula: see text]) are also discussed.

The kinetics of polysulphone formation IV. The isomerization of cis - and trans -2-butene accompanying polysulphone formation

1955 ◽  
Vol 229 (1179) ◽  
pp. 525-536 ◽  
Keyword(s):  
Sulphur Dioxide ◽  
Kinetic Studies ◽  
Ideal Liquid ◽  
Isomerization Reaction ◽  
Kcal Mole ◽  
Geometrical Isomerization ◽  
Ceiling Temperature ◽  
Liquid Sulphur ◽  
Cis And Trans ◽  
Kinetics Of

It has been shown by infra-red spectroscopic measurements that, at temperatures near the ‘ceiling temperature’, the copolymerization of sulphur dioxide with either cis - or trans -2- butene is accompanied by the geometrical isomerization of the 2-butene. The results of some kinetic studies of this latter reaction, using a vapour-pressure technique, are reported. Over the range investigated (25 to 60°C inclusive) the rate of this isomerization reaction increases with temperature according to the normal Arrhenius law, the overall energies of activation using benzoyl peroxide as the initiator being 16·5 ± 0·6 kcal mole –1 for the cis to trans isomerization and 18∙3 ± 0∙4 kcal mole –1 for the trans to cis isomerization. Prolonged reaction leads to the attainment of cis-trans equilibrium, and the value of the relevant thermodynamic functions are cis -2-butene→ trans -2-butene; in liquid sulphur dioxide, x B = 0∙09; ∆ H = – 1∙43 ± 0∙25 kcal mole –1 , ∆ S = – 2∙8 ± 0∙8 cal deg –1 mole –1 . These values differ from the values for an ideal liquid mixture of the cis - and trans -2-butenes. At 100°C and at high catalyst concentrations an additional isomerization reaction is detect­able; namely, that of formation of 1-butene by double-bond migration. The geometrical isomerization data are entirely consistent with the conclusion that the polymers formed from cis - and trans -2-butene are stereoisomeric (see also part III) and that one form of addition in the propagation step has a slightly lower energy of activation than the other.

The kinetics of elementary reactions involving the oxides of sulphur I. The nature of the sulphur dioxide afterglow

1966 ◽  
Vol 295 (1443) ◽  
pp. 355-362 ◽  
Keyword(s):  
Nitrogen Dioxide ◽  
Sulphur Dioxide ◽  
Active Species ◽  
Kcal Mole ◽  
Elementary Reactions ◽  
Kinetics Of

Studies of the sulphur dioxide afterglow in the products of a weak discharge through sulphur dioxide and argon show that the main active species are O and SO. The chemiluminescent combination of these species produces the sulphur dioxide after glow, the intensity of which is proportional to [O] [SO]. Sulphur monoxide reacts rapidly with nitrogen dioxide SO + NO 2 = SO 2 + NO + 59 kcal/mole. (3) Titration of the sulphur dioxide afterglow with nitrogen dioxide yields the sum of the O and SO concentrations, since reaction (2) is also fast, O + NO 2 = NO + O 2 + 46 kcal/mole. (2) The ratio k 2 / k 3 was found to be 0·67 ± 0·07 at 298°K. Klein & Herron’s (1964) value of k 2 yields k 3 = 5 x 10 12 cm 3 mole -1 s -1 at 298°K.

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