Rate constant ratios in the consecutive chlorination of liquid‐phase p ‐xylene with Cl 2 and an iron(III) chloride catalyst

2021 ◽  
Author(s):  
Fotis P. Rigas
Keyword(s):  
Liquid Phase ◽  
Rate Constant ◽  
Chloride Catalyst

A thermodynamic study of the dimerization of cyclopentadiene

1968 ◽  
Vol 21 (7) ◽  
pp. 1789 ◽  
Author(s):  
AG Turnbull ◽  
HS Hull
Keyword(s):  
Liquid Phase ◽  
Rate Constant ◽  
Vapour Pressure ◽  
Boiling Point ◽  
Strain Energy ◽  
Order Rate Constant ◽  
Adiabatic Calorimeter ◽  
Thermodynamic Study ◽  
Heats Of Formation ◽  
Kcal Mole

The heat of dimerization of cyclopentadiene to endo-dicyciopentadiene in the liquid phase at 25� was measured in an adiabatic calorimeter to be -9.22 � 0.3 kcal/mole monomer. The rate of dimerization in the liquid phase at 25� was followed with a dilatometer and the initial second-order rate constant found to be 4.99 x 10-5. mole-l min-l. The vapour pressure of endo-dicyclopentadiene, measured by a boiling point method in the range 77.5-149.6�, gave the relation (p in torr): RInp ? 11342/T -2.6505In T + 54.7855 The standard heats of formation of solid, 31.1 � 0.5 kcal/mole, and gaseous, 42.2 � 0. 6 kcal/mole, endo-dicyclopentadiene were derived, and the strain energy and dimerization equilibria discussed.

Isoméirsation cis–trans de l'azobenzène catalysée par l'iode. III

1974 ◽  
Vol 52 (10) ◽  
pp. 1868-1871 ◽  
Author(s):  
René Arnaud ◽  
Jacques Lemaire
Keyword(s):  
Liquid Phase ◽  
Rate Constant ◽  
Surface Effects ◽  
High Reactivity ◽  
Trans Isomerization ◽  
Low Concentrations ◽  
Very High

The cis–trans isomerization of azobenzene can be catalyzed by iodine. The rate constant for the reaction of cis-azobenzene with iodine atoms was determined as 2 ± 1 × 106 mol−1 1 s−1, i.e. a much larger value than that pertaining to other isomerizable systems. This very high reactivity of cis-azobenzene allowed the demonstration of surface effects which were unexpected in the liquid phase. A method for estimating low concentrations of iodine atoms can be based on this catalyzed isomerization. [Journal translation]

scholarly journals The Rate Constant Measurements of Liquid Phase Rapid Reactions

1965 ◽  
Vol 68 (1) ◽  
pp. 63-67 ◽  
Author(s):  
Sakae YAGI ◽  
Hiroyoshi INOUE ◽  
Eiji OSHIMA ◽  
Toshio KOBAYASHI
Keyword(s):  
Liquid Phase ◽  
Rate Constant

Liquid phase oxidation of mesitylene to 3,5-dimethylbenzaldehyde

1986 ◽  
Vol 51 (11) ◽  
pp. 2574-2581 ◽  
Author(s):  
Gabriela Valehrachová ◽  
Milan Hronec ◽  
Václav Veselý
Keyword(s):  
Liquid Phase ◽  
Rate Constant ◽  
Liquid Phase Oxidation ◽  
Reaction Selectivity ◽  
Subsequent Oxidation ◽  
Phase Oxidation

Liquid phase oxidation of mesitylene to 3,5-dimethylbenzaldehyde has been studied in the presence of cobalt bromide catalysts activated with triethanolamine or pyridine. The selectivity for the aldehyde is affected by the presence of the amine, by solvent, and only little by concentration of the catalyst and its components. The lower value of rate constant of the subsequent oxidation of the aldehyde, k2 = (7.66 ± 0.39) . 10-5 s-1, as compared with that of the oxidation of mesitylene, k1 = (1.66 ± 0.13) . 10-4 s-1 at 60 °C, indicates an important role of the cooxidation reactions in the process of oxidation of mesitylene, which affects the reaction selectivity.

Oxidation of nitrobenzene by ozone in the presence of faujasite zeolite in a continuous flow gas–liquid–solid reactor

2010 ◽  
Vol 62 (5) ◽  
pp. 1076-1083 ◽  
Author(s):  
J. Reungoat ◽  
J. S. Pic ◽  
M. H. Manéro ◽  
H. Debellefontaine
Keyword(s):  
Liquid Phase ◽  
Chemical Oxygen Demand ◽  
Transfer Coefficient ◽  
Rate Constant ◽  
Decomposition Rate ◽  
Oxidation Rate ◽  
Continuous Flow ◽  
Oxygen Demand ◽  
Decomposition Rate Constant ◽  
Faujasite Zeolite

This work investigates the oxidation of nitrobenzene (NB) by ozone in the presence of faujasite zeolite. Experiments were carried out in a gas–liquid–solid reactor were ozone transfer and NB oxidation took place at the same time. Three configurations of the reactor were compared: empty, filled with inert glass beads and filled with faujasite pellets. First, ozone transfer coefficient (kLa) and decomposition rate constant (kC) were determined for each configuration. In presence of solid, kLa was 2.0 to 2.6 times higher and kC was 5.0 to 6.4 times higher compared to the empty reactor. Then, the various configurations were evaluated in terms of NB removal and chemical oxygen demand (COD) decrease. The faujasite reactor showed higher removal of NB and decrease of COD compared to other configurations under the same conditions suggesting that the faujasite increases the oxidation rate of NB. Oxidation of NB in presence of faujasite also proved to be limited by the transfer of ozone from the gas to the liquid phase.

The absolute value of the rate constant of the liquid-phase reaction SO 5 −. + Fe(II)

2006 ◽  
Vol 47 (3) ◽  
pp. 341-346 ◽  
Author(s):  
O. A. Travina ◽  
A. N. Ermakov ◽  
Yu. N. Kozlov ◽  
A. P. Purmal
Keyword(s):  
Liquid Phase ◽  
Rate Constant ◽  
Phase Reaction ◽  
Absolute Value ◽  
The Absolute ◽  
Liquid Phase Reaction

Kinetics in Heterogeneous Systems

2007 ◽  
Author(s):  
Robert B. Jordan
Keyword(s):  
Liquid Phase ◽  
Mass Transport ◽  
Rate Constant ◽  
Heterogeneous Systems ◽  
Two Phase ◽  
First Order ◽  
Liquid Phases ◽  
Liquid Systems ◽  
The Difference ◽  
Two Phases

In this Chapter, a heterogeneous system is one in which the reactants are present in at least two phases. The discussion will concentrate on two such conditions, two-phase gas/liquid systems and three-phase gas/liquid/solid systems. Chemists tend to favor homogeneous conditions, with the reactants all in one phase, because they provide more controlled and reproducible conditions. However, heterogeneous conditions are often preferred in industrial processes because of the ease of separating the catalyst from the products. In many mechanistic studies, heterogeneity adds a complicating feature to be avoided, but there are times when this cannot be done, or when it happens unexpectedly. In gas/liquid systems, the gas often has limited solubility in the liquid which contains the other reagents. As a consequence, there can be problems of mass transport of the gaseous reactant from the gas to the liquid phase. Mass transport can limit the concentration of the gas in the liquid and/or become a rate-limiting feature of the system. These features can confuse interpretations of product distributions and rate laws. The gas/liquid/solid systems generally involve reactants in the gas and liquid phases and a catalyst as the solid phase. In some cases, the solid may be produced from initially homogeneous conditions, and a question arises as to whether the real catalyst is the original species added or the solid product formed under the reaction conditions. There are further questions about the factors that may control the rate of the catalytic process. In the chemistry laboratory, these systems are most often encountered with the gases H2 or CO reacting with substrate and possibly a catalyst in the liquid phase. For the mechanistic interpretation of kinetic observations, an important factor is the rate of mass transfer of the gas to the liquid phase. The rate of gas absorption into the liquid is typically represented as a first order process, driven by the difference between the saturated gas concentration [G(I)]f and the concentration at any time [G(I)], as given by where kLA is an effective first-order rate constant. This constant is taken as a product of an inherent absorption rate constant, kL, and something related to the surface area of the liquid phase, A.

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