Kinetics and Thermodynamic Data for the Hydrogen Fluoride Addition to Vinyl Fluoride

1971 ◽  
Vol 49 (15) ◽  
pp. 2471-2475
Author(s):  
Leonard O. Moore
Keyword(s):  
Hydrogen Fluoride ◽  
Equilibrium Constants ◽  
Frequency Factor ◽  
Vinyl Fluoride ◽  
A Value ◽  
Reaction Data ◽  
Factor Log ◽  
Kinetics Of ◽  
Fluoride Addition ◽  
Kinetics And Thermodynamic

The kinetics of the addition of hydrogen fluoride to vinyl fluoride have been measured in the vapor phase at temperatures of 100 and 150 °C and under pressures of 170, 308, and 446 N/m2. The rate equation was found to be a typical second order expression, −dx/dt = k [CHF=CH2] [HF]. The energy of activation was calculated to be 17 ± 2 kcal/mol, and the frequency factor, log A (l/mol s) was 6 ± 1. Based on reaction data from the literature, equilibrium constants and a value for ΔH298 were calculated. For this reaction, ΔH298 is about −12 kcal/mol.

Pyrolytic Characteristics and Kinetic Parameters Evaluation of Cassava Stalks Using Thermogravimetric Analyzer

2020 ◽  
Vol 851 ◽  
pp. 137-141
Author(s):  
Sukarni Sukarni ◽  
M. Rifqi Ramadhan
Keyword(s):  
Reaction Order ◽  
Frequency Factor ◽  
Differential Method ◽  
Nitrogen Flow ◽  
Nitrogen Flow Rate ◽  
Kinetic Evaluation ◽  
Thermogravimetric Analyzer ◽  
Second Stage ◽  
Factor Log ◽  
Kinetics Of

Pyrolytic characteristics and kinetics of cassava stalks as a renewable energy source were delved via a thermogravimetric (TG) analyzer. About 10 mg powder of the sample was heated up in the TG cavity under inert conditions with 50 ml.min-1 nitrogen flow rate and operated at 20 °C min-1 of heating program. The pyrolysis process of cassava stalks was taken place into three main stages, in which the peak reaction occurred at the second stage with 70% of the mass was degraded. The differential method of Arrhenius kinetic evaluation resulted in the values of reaction order (n) that was 0.99, activation energy that was 89.46 kJ/mol and logarithmic frequency factor (log A) was 7.7 min-1.

Kinetics of the recombination of methyl radicals with benzyl radicals

1967 ◽  
Vol 45 (6) ◽  
pp. 575-578 ◽  
Author(s):  
R. J. Kominar ◽  
M. G. Jacko ◽  
S. J. Price
Keyword(s):  
Frequency Factor ◽  
Ethyl Benzene ◽  
Recombination Reaction ◽  
Methyl Radicals ◽  
Kcal Mole ◽  
Arrhenius Parameters ◽  
Temperature Range ◽  
A Value ◽  
Benzyl Radicals ◽  
Kinetics Of

The recombination of methyl and benzyl radicals has been studied over the temperature range 529 to 799 °K. The Arrhenius parameters for the recombination reaction are log A (cc mole−1 s−1) = 11.20, E = 0.20 kcal mole−1. The frequency factor at 1 000 °K for the reverse reaction, the dissociation of ethyl benzene, is calculated to be log A (s−1) = 14.9. A value of 70.5 kcal mole−1 has been estimated for D(C6H5CH2—CH3).

Electroreduction of Cr(VI) from solutions of bifunctional alcohols

1989 ◽  
Vol 54 (10) ◽  
pp. 2638-2643
Author(s):  
David I. Balanchivadze ◽  
Tamara R. Chelidze ◽  
Jondo J. Japaridze
Keyword(s):  
Activation Energy ◽  
Ethylene Glycol ◽  
Electrode Surface ◽  
Frequency Factor ◽  
Limiting Current ◽  
Factor Log ◽  
Standard Rate ◽  
Standard Rate Constant ◽  
Chromate Ion ◽  
Activation Energy Of Diffusion

The effect of bifunctional alcohols ethylene glycol (EG) and 1,2-propylene glycol (1,2 PG) on the kinetic parameters for the irreversible chromate ion reduction were investigated by polarographic and coulometric methods of analysis. The electroreduction of chromate ion in neutral bifunctional alcohol solutions proceeds according to the scheme: Cr(VI)–Cr(III)–Cr(II) and the values of the standard rate constant k*0 decrease in the order H2O > EG > 1,2 PG. The values of real activation energy, Q, activation energy of diffusion, QD, and frequency factor log A° have been calculated. The obtained values of QD as well as Q proved the diffusion nature of limiting current. The values of the frequency factor log A° decrease in the order H2O > EG > 1,2 PG, which points to a less favourable orientation of the electroactive ions at the electrode surface in glycols.

scholarly journals Recognition of hydrogen isotopomers by an open-cage fullerene

2013 ◽  
Vol 371 (1998) ◽  
pp. 20110629 ◽  
Author(s):  
Yasujiro Murata ◽  
Shih-Ching Chuang ◽  
Fumiyuki Tanabe ◽  
Michihisa Murata ◽  
Koichi Komatsu
Keyword(s):  
Equilibrium Constants ◽  
Equilibrium Mixture ◽  
Size Difference ◽  
Binding Affinities ◽  
Kinetic Isotope ◽  
Molecular Sizes ◽  
Lower Temperature ◽  
Kinetics Of ◽  
Pressure Hydrogen

We present our study on the recognition of hydrogen isotopes by an open-cage fullerene through determination of binding affinity of isotopes H 2 /HD/D 2 with the open-cage fullerene and comparison of their relative molecular sizes through kinetic-isotope-release experiments. We took advantage of isotope H 2 /D 2 exchange that generated an equilibrium mixture of H 2 /HD/D 2 in a stainless steel autoclave to conduct high-pressure hydrogen insertion into an open-cage fullerene. The equilibrium constants of three isotopes with the open-cage fullerene were determined at various pressures and temperatures. Our results show a higher equilibrium constant for HD into open-cage fullerene than the other two isotopomers, which is consistent with its dipolar nature. D 2 molecule generally binds stronger than H 2 because of its heavier mass; however, the affinity for H 2 becomes larger than D 2 at lower temperature, when size effect becomes dominant. We further investigated the kinetics of H 2 /HD/D 2 release from open-cage fullerene, proving their relative escaping rates. D 2 was found to be the smallest and H 2 the largest molecule. This notion has not only supported the observed inversion of relative binding affinities between H 2 and D 2 , but also demonstrated that comparison of size difference of single molecules through non-convalent kinetic-isotope effect was applicable.

scholarly journals Evaluation of equilibrium constants for the interaction of lactate dehydrogenase isoenzymes with reduced nicotinamide-adenine dinucleotide by affinity chromatography

1975 ◽  
Vol 151 (3) ◽  
pp. 631-636 ◽  
Author(s):  
R I Brinkworth ◽  
C J Masters ◽  
D J Winzor
Keyword(s):  
Lactate Dehydrogenase ◽  
Affinity Chromatography ◽  
Equilibrium Constants ◽  
Mouse Tissue ◽  
Rabbit Muscle ◽  
Muscle Lactate ◽  
Sodium Phosphate Buffer ◽  
A Value ◽  
Series Of Experiments ◽  
Reduced Nicotinamide Adenine Dinucleotide

Rabbit muscle lactate dehydrogenase was subjected to frontal affinity chromatography on Sepharose-oxamate in the presence of various concentrations of NADH and sodium phosphate buffer (0.05 M, pH 6.8) containing 0.5 M-NaCl. Quantitative interpretation of the results yields an intrinsic association constant of 9.0 × 104M−1 for the interaction of enzyme with NADH at 5°C, a value that is confirmed by equilibrium-binding measurements. In a second series of experiments, zonal affinity chromatography of a mouse tissue extract under the same conditions was used to evaluate assoication constants of the order 2 × 105M−1, 3 × 105M−1, 4 × 105M−1, 7 × 105M−1 and 2 × 106M−1 for the interaction of NADH with the M4, M3H, M2H2, MH3 and H4 isoenzymes respectively of lactate dehydrogenase.

scholarly journals The kinetics of the oxidation of copper. Part II. -The limiting pressure. Evidence for the lateral diffusion of adsorbed gas

1930 ◽  
Vol 128 (808) ◽  
pp. 407-417 ◽  
Keyword(s):  
Lateral Diffusion ◽  
Adsorbed Gas ◽  
A Value ◽  
Kinetics Of ◽  
Limiting Pressure

The influence of the pressure of oxygen on the rate of oxidation of copper has been studied by earlier workers. Pilling and Bedworth working at 800°C. found that the rate of oxidation continued constant as the pressure was decreased until the pressure reached 0·3 mm. Berger found a limiting pressure of 100 mm. Hinshelwood’s work makes it clear that for activated copper at 305°C. the limiting pressure is greater than 5 mm. Palmer obtained a value of about 300 mm. The object of this work was to investigate more closely the significance of the limiting pressure.

The kinetics of action of acetylcholine antagonists in smooth muscle

1966 ◽  
Vol 164 (996) ◽  
pp. 488-510 ◽  
Keyword(s):  
Smooth Muscle ◽  
Binding Capacity ◽  
Equilibrium Constants ◽  
Dose Effect ◽  
Analogue Computer ◽  
Kinetic Properties ◽  
Receptor Complexes ◽  
Rate Limiting Step ◽  
Drug Receptor ◽  
Kinetics Of

The rate-limiting step in recovery of acetylcholine sensitivity in smooth muscle after exposure to atropine or hyoscine could be the dissociation of drug-receptor complexes (dissociationlim ited model) or diffusion of drug away from the neighbourhood of the receptors (biophase model). These two models differ in the details of the predicted kinetics of development and decline of antagonism. Their theoretical kinetic properties have been worked out mathematically with the aid of an analogue computer, and com pared with experimental measurements made in guinea-pigileum longitudinal muscle preparations. The kinetic properties of antagonists applied singly could be explained either by the dissociation-limited model, or by the biophase model, provided that the size of the biophase bore a certain relation to the binding capacity of the receptors. In studies of the interaction of fastand slow-acting antagonists, it was found that the dissociation-limited model could alone account for the observed effects. It was concluded that the kinetics of action of hyoscine and atropine reflected their rate of reaction with receptors, an d that measurements of antagonist kinetics were a valid guide to drug-receptor rate constants. A consequence of the dissociation-limited model, that persistent antagonists should fail to show the classical parallel shift of log-dose effect curves when tested against agonists of low efficacy, was borne out experimentally, and this effect was used to estimate indirectly the equilibrium constants of alkyltrimethylammonium salts.

Kinetic and Equilibrium Studies of the Reactions of Cyanide Ion with 1,3,5-Trinitrobenzene, 2,4,6-Trinitroanisole, and 2,4,6-Trinitrotoluene in Isopropanol

1974 ◽  
Vol 52 (1) ◽  
pp. 8-17 ◽  
Author(s):  
Leong Huat Gan ◽  
Albert Richard Norris
Keyword(s):  
Standard Enthalpy ◽  
Equilibrium Constants ◽  
Activation Parameters ◽  
Stopped Flow ◽  
Cyanide Ion ◽  
Equilibrium Studies ◽  
Kinetics Of Formation ◽  
Kinetics Of

Equilibrium constants for the formation of 1:1 cyanide ion σ-complexes with 1,3,5-trinitrobenzene, 2,4,6-trinitroanisole, and 2,4,6-trinitrotoluene have been determined spectrophotometrically over a range of temperatures. Standard enthalpy (ΔH0) and entropy (ΔS0) changes associated with each reaction have been evaluated. The kinetics of formation of the σ-complexes have been investigated by means of a stopped-flow technique and the activation parameters characterizing the formation of each complex have been determined. Evidence is presented which indicates the cyanide ion – 2,4,6-trinitroanisole σ-complex formed in isopropanol contains the cyanide ion bonded exclusively at the C-3 position.

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