KINETICS OF THE REACTION H + D2 = HD + D

1964 ◽  
Vol 42 (11) ◽  
pp. 2480-2487 ◽  
Author(s):  
W. R. Schulz ◽  
D. J. Le Roy
Keyword(s):  
Rate Constant ◽  
Theoretical Work ◽  
Temperature Range ◽  
Kinetics Of

The authors have measured the rate constant for the reaction H + D2 = HD + D in the temperature range 368–68° K. This was found to be given by the relation:[Formula: see text]A comparison is made with previous experimental and theoretical work on the reaction.

Kinetics of the reaction H + C2H6 → H2 + C2H5 in the temperature region of 1000 K

1984 ◽  
Vol 62 (1) ◽  
pp. 86-91 ◽  
Author(s):  
J.-R. Cao ◽  
M. H. Back
Keyword(s):  
Equilibrium Constant ◽  
Rate Constant ◽  
Temperature Region ◽  
Recent Measurement ◽  
Hydrogen Atoms ◽  
Elementary Reactions ◽  
Temperature Range ◽  
Hydrogen Molecules ◽  
Kinetics Of ◽  
Rate Controlling Step

A system for the measurement of rate constants for elementary reactions of hydrogen atoms in the temperature region of 1000 K is described. The concentration of hydrogen atoms is controlled by the equilibrium constant for dissociation of hydrogen molecules. The kinetics of the rate of conversion of ethane to ethylene in this system has been studied over the temperature range 876–1016 K. The results show that the rate-controlling step is[Formula: see text]and the value obtained for the rate constant is[Formula: see text](R = 1.987 cal mol−1 deg−1). This value is compared with values obtained from other methods over the temperature range 300–1400 K. Combination with a recent measurement of the rate constant for the reverse reaction yields an experimental value for the equilibrium constant for the reaction.

KINETICS OF THE REACTION H + CH4 = CH3 + H2

1954 ◽  
Vol 32 (7) ◽  
pp. 650-659 ◽  
Author(s):  
M. R. Berlie ◽  
D. J. Le Roy
Keyword(s):  
Rate Constant ◽  
Methyl Radical ◽  
Temperature Range ◽  
Kinetics Of

The reaction H + CH4 = CH3 + H2 has been studied in the temperature range 99° to 163 °C. The rate constant is given by the expression k = 1.7 × 10−14 exp (−4500/RT). The data are in agreement with the results, but not the interpretations, of previous work. The entropy of the methyl radical has been calculated for several temperatures.

Kinetics of the Reaction of Nickel(II) and 2,2′-Bipyridine in Ethanol

1973 ◽  
Vol 51 (23) ◽  
pp. 3975-3977 ◽  
Author(s):  
M. L. Sanduja ◽  
W. MacF. Smith
Keyword(s):  
Kinetic Parameters ◽  
Rate Constant ◽  
Order Rate Constant ◽  
Second Order ◽  
Stopped Flow ◽  
Ligand Specificity ◽  
Temperature Range ◽  
Kinetics Of Formation ◽  
The Difference ◽  
Kinetics Of

The kinetics of formation of the monobipyridine complex of nickel(II) in ethanol has been studied with stopped-flow methods over the temperature range 7 to 35 °C. The value of the second order rate constant kf at 25 °C of 6.6 × 10−3M−1 s1 and the values of ΔH≠ (10.1 ± 1.0 kcal mol−1) and of ΔS≠ (−7.3 ± 3.4 cal deg−1 mol−1) are close to the corresponding values for ethanol exchange on nickel(II) and suggest that the mechanism is dissociative interchange. However the difference in the values of the kinetic parameters of this reaction and those previously reported for the reactions involving the chemically similar phenanthroline imply a degree of ligand specificity for the reactions in ethanol which is considerably larger than is the case for reactions in water and methanol and that a common Id mechanism with monodentate formation being rate controlling is not applicable to both reactions.

Kinetics of the reaction C2H5 + H2 → C2H6 + H from 1111-1200 K

1982 ◽  
Vol 60 (24) ◽  
pp. 3039-3048 ◽  
Author(s):  
J.-R. Cao ◽  
M. H. Back
Keyword(s):  
Rate Constant ◽  
Equilibrium Concentration ◽  
Reverse Reaction ◽  
Elementary Reaction ◽  
Hydrogen Atoms ◽  
Temperature Range ◽  
Lower Temperature ◽  
Kinetics Of ◽  
Rate Controlling Step ◽  
Hydrogenation Of Ethylene

A system for the measurement of the rate constant for the elementary reaction[Formula: see text]in the temperature range 1111–1200 K is described and is based on the thermal production of an equilibrium concentration of hydrogen atoms. In a mixture of hydrogen with about 10 ppm ethylene this reaction is the rate-controlling step in the hydrogenation of ethylene. The product ethane undergoes rapid secondary dissociation and the final product is methane. The values obtained in the present work, which are represented by the following expression,[Formula: see text](R = 1.987 cal mol−1 deg−1) are compared to those obtained at lower temperature (820–350 K) and to those calculated from measurements of the reverse reaction.

The kinetics of the reaction between O 2 ( 1 ∆ g ) and ozone

1970 ◽  
Vol 317 (1530) ◽  
pp. 407-416 ◽  
Keyword(s):  
Activation Energy ◽  
Rate Constant ◽  
Room Temperature ◽  
Published Data ◽  
Temperature Range ◽  
A Value ◽  
Kinetics Of

The kinetics of the reaction O 2 ( 1 ∆ g ) + O 3 k 2 → 2O 2 + O have been investigated in the temperature range 195 to 439 K by using the kinetic photo­ionization technique to follow [O 2 ( 1 ∆ g )]. In Arrhenius form, the rate constant, k 2 ,'is given by k 2 = 4.0 ± 1.5 x 10 8 exp (13000 /RT) 1 mol -1 s -1 (joule units) ( = 4.0 ± 1.5 x 10 8 exp (3100/RT) 1 mol -1 s -1 (calorie units)). At room temperature (292 K) k 2 = 2.1 ± 0.3 x 10 6 1 mol -1 s -1 . The activation energy of 13 ± 1.6 kJ mol -1 suggests that there is virtually no barrier to the reaction other than that provided by its endothermicity (12.1 kJ mol -1 ). The results are used to derive, from pre­viously published data, a value of the rate constant for the reaction O + O 3 k 3 → 2O 2 of 4 ± 2 x 10 6 1 mol -1 s -1 at room temperature.

scholarly journals Kinetics of the gas-phase reaction of hydroxyl radicals with trimethyl phosphate over the 273–837 K temperature range

RSC Advances ◽  
2021 ◽  
Vol 11 (23) ◽  
pp. 14121-14131
Author(s):  
P. V. Koshlyakov ◽  
D. A. Barkova ◽  
I. E. Gerasimov ◽  
E. N. Chesnokov ◽  
Xiaokai Zhang ◽  
...  
Keyword(s):  
Gas Phase ◽  
Hydroxyl Radicals ◽  
Rate Constant ◽  
Phase Reaction ◽  
Trimethyl Phosphate ◽  
Gas Phase Reaction ◽  
Temperature Range ◽  
P Rate ◽  
Kinetics Of

Rate constant of reaction 1 at 1 bar, over the temperature range 273–837 K.

Kinetics of Substitution of 4-Methoxyphenylazo Groups of 2,6-Dioxo-5(3)-(4-methoxyphenylazo)-3(5)-(4-methoxyphenylhydrazono)-1,2,3,6-tetrahydropyridine-4-carboxylic Acid by Reaction with 4-Nitrobenzenediazonium Cation

1994 ◽  
Vol 59 (7) ◽  
pp. 1665-1672 ◽  
Author(s):  
Jaroslava Horáčková ◽  
Vojeslav Štěrba
Keyword(s):  
Carboxylic Acid ◽  
Rate Constant ◽  
Kinetics Of

Kinetics have been studied of gradual replacement of 4-methoxyphenylazo groups in 2,6-dioxo-5(3)-(4-methoxyphenylazo)-3(5)-(4-methoxyphenylhydrazono)-1,2,3,6-tetrahydropyridine-4-carboxylic acid (IIIa) by 4-nitrophenylazo groups using the reaction with 4-nitrobenzenediazonium cation (IIc) in acetate and phosphate buffers. The rate constant of replacement of the second methoxyphenylazo group is lower by a factor of ca 60. From the experimentally found pKa values of the corresponding azohydrazone compounds with methoxy, chloro, or nitro substituent at 4-position (IIIa - IIIf) it has been concluded that the 5(3)-(4-methoxyphenylazo)-3(5)-(4-nitrophenylhydrazono) derivative is formed in the first step.

scholarly journals Simultaneous Kinetics of Selenite Oxidation and Sorption on δ-MnO2 in Stirred-Flow Reactors

2021 ◽  
Vol 18 (6) ◽  
pp. 2902
Author(s):  
Zheyong Li ◽  
Yajun Yuan ◽  
Lin Ma ◽  
Yihui Zhang ◽  
Hongwei Jiang ◽  
...  
Keyword(s):  
Rate Constant ◽  
Photoelectron Spectroscopy ◽  
Oxide Surfaces ◽  
Kinetic Rate Constant ◽  
Flow Reactors ◽  
Mn Oxide ◽  
Remediation Strategies ◽  
Process Of Se ◽  
Kinetics Of

Selenium (Se) is an essential and crucial micronutrient for humans and animals, but excessive Se brings negativity and toxicity. The adsorption and oxidation of Se(IV) on Mn-oxide surfaces are important processes for understanding the geochemical fate of Se and developing engineered remediation strategies. In this study, the characterization of simultaneous adsorption, oxidation, and desorption of Se(IV) on δ-MnO2 mineral was carried out using stirred-flow reactors. About 9.5% to 25.3% of Se(IV) was oxidized to Se(VI) in the stirred-flow system in a continuous and slow process, with the kinetic rate constant k of 0.032 h−1, which was significantly higher than the apparent rate constant of 0.0014 h−1 obtained by the quasi-level kinetic fit of the batch method. The oxidation reaction was driven by proton concentration, and its rate also depended on the Se(IV) influent concentration, flow rate, and δ-MnO2 dosage. During the reaction of Se(IV) and δ-MnO2, Mn(II) was produced and adsorbed strongly on Mn oxide surfaces, which was evidenced by the total reflectance Fourier transform infrared (ATR-FTIR) results. The X-ray photoelectron spectroscopy (XPS) data indicated that the reaction of Se(VI) on δ-MnO2 produced Mn(III) as the main product. These results contribute to a deeper understanding of the interface chemical process of Se(IV) with δ-MnO2 in the environment.

scholarly journals Physical properties and water absorption kinetics of three varieties of Mucuna beans

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ajibola B. Oyedeji ◽  
Olajide P. Sobukola ◽  
Ezekiel Green ◽  
Oluwafemi A. Adebo
Keyword(s):  
Physical Properties ◽  
Water Absorption ◽  
Rate Constant ◽  
Geometric Mean ◽  
Seed Mass ◽  
Activation Energies ◽  
Mucuna Pruriens ◽  
Absorption Kinetics ◽  
Kinetics Of ◽  
Soaking Temperature

AbstractThe physical properties and water absorption kinetics of three varieties of Mucuna beans (Mucuna pruriens, Mucuna rajada and Mucuna veracruz) were determined in this study. Physical properties including length, width, thickness, geometric mean diameter, sphericity, porosity, bulk density, area, volume and one thousand seed mass were calculated while hydration kinetics was studied by soaking Mucuna beans in water at 30 °C, 40 °C and 50 °C and measuring water uptake at 9 h interval. Peleg’s equation was used to model the hydration characteristics and Arrhenius equation was used to describe the effect of temperature on Peleg’s rate constant k1 and to obtain the activation energies for soaking. Significant variations were observed in almost all the physical properties of the different varieties, however, there were no significant differences (p < 0.05) in their thicknesses and bulk densities. The effectiveness of fit of Peleg’s model (R2) increased with increase in soaking temperature. Peleg’s rate constant k1 decreased with increase in soaking temperature while k2 increased with temperature increase. Activation energies of Mucuna pruriens, Mucuna rajada and Mucuna veracruz were 1613.24 kJ/mol, 747.95 kJ/mol and 2743.64 kJ/mol, respectively. This study provides useful information about the properties of three varieties of Mucuna beans that could be of importance to processors and engineers for process design and optimization.

Sign in / Sign up

Export Citation Format

Share Document