scholarly journals THE REACTION OF OXYGEN ATOMS WITH CARBON TETRACHLORIDE

1962 ◽  
Vol 40 (3) ◽  
pp. 486-494 ◽  
Author(s):  
A. Y-M. Ung ◽  
H. I. Schiff
Keyword(s):  
Carbon Dioxide ◽  
Carbon Tetrachloride ◽  
Carbon Atom ◽  
Flow System ◽  
Primary Process ◽  
Chain Mechanism ◽  
Homogeneous Reaction ◽  
Secondary Reactions ◽  
Primary Reactions ◽  
A Chain

The homogeneous reaction between O atoms and CCl4 was studied in a flow system under conditions of complete consumption of atoms, in the presence and in the absence of molecular oxygen. The only products of the reaction are Cl2, CO, CO2, and COCl2. No compounds containing more than one carbon atom were detected. The dependence of the products on CCl4 concentration suggests that the primary reactions are[Formula: see text]which are too slow to consume all the atoms. Carbon dioxide is produced by secondary reactions which are fast enough to consume all the atoms, the most important of which is[Formula: see text]However, the dependence of the ratio (CO2 + COCl2/CO on CCl4 concentration in the presence of O2 indicates other reactions also produce CO2. The rapid disappearance of O atoms in the systems containing O2 suggests a chain mechanism in which Cl2 is mainly converted to the atomic form. Carbon dioxide can then be produced by the sequence[Formula: see text]The rate constant for the primary process was found to be independent of O, O2, and CCl4 concentration and could be represented by the equation[Formula: see text]

THE KINETICS OF THE OXIDATION OF GASEOUS ACETALDEHYDE

1932 ◽  
Vol 7 (2) ◽  
pp. 149-161 ◽  
Author(s):  
W. H. Hatcher ◽  
E. W. R. Steacie ◽  
Frances Howland
Keyword(s):  
Carbon Dioxide ◽  
Formic Acid ◽  
Induction Period ◽  
Reaction Vessel ◽  
Oxidation Products ◽  
Main Reaction ◽  
Chain Mechanism ◽  
Subsequent Reaction ◽  
A Chain ◽  
Kinetics Of

The kinetics of the oxidation of gaseous acetaldehyde have been investigated from 60° to 120 °C. by observing the rate of pressure decrease in a system at constant volume. A considerable induction period exists, during which the main products of the reaction are carbon dioxide, water, and formic acid. The main reaction in the subsequent stages involves the formation of peroxides and their oxidation products. The heat of activation of the reaction is 8700 calories per gram molecule. The indications are that the reactions occurring during the induction period are heterogeneous. The subsequent reaction occurs by a chain mechanism. The chains are initiated at the walls of the reaction vessel, and are also largely broken at the walls.

THE PHOTOINITIATED HALOGENATION REACTIONS OF N-BROMOACETANILIDE AND N-BROMO-2,4,6-TRICHLOROACETANILIDE

1966 ◽  
Vol 44 (13) ◽  
pp. 1555-1562
Author(s):  
Dennis D. Tanner ◽  
Eugene Protz
Keyword(s):  
Carbon Tetrachloride ◽  
Bromine Atom ◽  
Benzyl Bromide ◽  
Chain Process ◽  
Chain Mechanism ◽  
Chain Component ◽  
Rearrangement Reaction ◽  
A Chain ◽  
Photoinduced Rearrangement ◽  
Long Chain

The photoinduced rearrangement reaction of N-bromoacetanilide to p-bromoacetanilide in carbon tetrachloride was found to have a quantum efficiency approaching unity, and evidence is presented to indicate a chain component to the reaction process whose product-determining species is either the mesomeric acetanilide radical or the bromine atom. It was demonstrated that small variations in the solvent composition affected the product ratio of p- to o-bromoacetanilide. The reaction of N-bromoacetanilide in carbon tetrachloride with added toluene was found to be a long-chain process producing p-bromoacetanilide as well as acetanilide and benzyl bromide. The bromination of toluene by N-bromo-2,4,6-trichloroacetanilide was shown to proceed by a chain mechanism involving the bromine radical as the chain-propagating species, and this mechanism is used as a model to explain the reaction of N-bromoacetanilide in dilute carbon tetrachloride solutions of toluene.

scholarly journals The combination of hydrogen and oxygen photosensitised by nitrogen peroxide

1933 ◽  
Vol 139 (837) ◽  
pp. 147-162 ◽  
Keyword(s):  
Hydrogen Peroxide ◽  
Spectroscopic Study ◽  
Gas Phase ◽  
Alternative Form ◽  
Chain Mechanism ◽  
Homogeneous Reaction ◽  
Chain Reaction ◽  
Chain Reactions ◽  
Temperature And Pressure ◽  
A Chain

The homogeneous reaction between hydrogen and oxygen has been proved by the work of Hinshelwood, of Haber, and of Semenoff to be a chain reaction, which under certain conditions of temperature and pressure may pass over into an explosive combination. The reaction is subject to the kinetics characteristic of certain types of chain reactions, in that, for any particular temperature, there are upper and lower pressure limits for explosion, the former controlled by deactivation of the chains in the gas phase, and the latter by their termination at the surface. The conditions further point to a branching chain mechanism; below 300°C. there is no observable propagation of reaction chains. These facts seem to be well represented by the scheme of Bonhoeffer and Haber, which was put forward on the basis of a spectroscopic study of the dissociation of steam at high temperatures. H + H 2 + O 2 = HO + H 2 O + 102,000 cals. (1) HO + H 2 = H 2 O + H + 10,000 cals. (2) reaction (1) sometimes taking the alternative form H + H 2 + O 2 = OH + OH + H - 2000 cals. (1a) which accounts for the branching of the chains. Reaction (2) does not occur appreciably at temperatures below 300°C., but the OH radicles yield hydrogen peroxide which may be detected.

The Photolysis of Benzoic Acid in the Vapor Phase

1972 ◽  
Vol 50 (13) ◽  
pp. 2017-2021 ◽  
Author(s):  
Francis Chau ◽  
Cyril Gibbons ◽  
Donald Barton
Keyword(s):  
Carbon Dioxide ◽  
Benzoic Acid ◽  
Vapor Phase ◽  
Ground State ◽  
Flow System ◽  
Incident Light ◽  
Chain Mechanism ◽  
Vibrationally Excited ◽  
Radical Chain ◽  
A Minor

The photolysis of benzoic acid in the vapor phase has been investigated in a flow system at temperatures ranging from 110–305 °C, pressures from 0.06–1.73 Torr, and at various incident light intensities. Carbon dioxide and benzene are the main products and carbon monoxide is a minor product. The rate of formation of carbon dioxide is proportional to the first power of the light intensity and is independent of benzoic acid concentration at pressures from 0.29–1.73 Torr. The activation energy for carbon dioxide formation is approximately 3 kcal per mol. A radical chain mechanism has been suggested, in which initiation results from decomposition of vibrationally excited ground state benzoic acid molecules, and termination occurs at the wall. A molecular mechanism is a possibility if the rate of formation of vibrationally excited ground state is a function of temperature.

Réactions ion–molécule dans les méthylbutènes: radiolyse du méthane

1976 ◽  
Vol 54 (4) ◽  
pp. 555-559
Author(s):  
Guy J. Collin
Keyword(s):  
Tertiary Structure ◽  
Ionic Mechanism ◽  
Chain Mechanism ◽  
A Chain

The radiolysis of gaseous methane has been studied in the presence of one of the three methylbutenes. We have observed an important isomerization of the added olefin. An ionic mechanism initiated by the CH5+ and C2H5+ ions seems to be compatible with the observations reported. Isomerization proceeds through a chain mechanism where the chain carrier may be the tert-C5H11+ ion. In the presence of 3-methyl-1-butene, the initially formed (CH3)2CHCHCH3+ ion isomerizes to the tertiary structure before producing the observed isomerization.

The quadrupole moment of the carbon dioxide molecule

1963 ◽  
Vol 273 (1353) ◽  
pp. 275-289 ◽  
Keyword(s):  
Carbon Dioxide ◽  
Carbon Atom ◽  
Quadrupole Moment ◽  
Polarizability Tensor ◽  
Sulphur Hexafluoride ◽  
Inhomogeneous Electric Field ◽  
Carbon Dioxide Molecule ◽  
Method Of Measurement ◽  
The Difference

A direct measurement of the magnitude and sign of the quadrupole moment of the carbon dioxide molecule has been made by determining the birefringence induced in gaseous C0 2 by an inhomogeneous electric field. The method of measurement and the experimental details are described. The observable is the product of the molecular quadrupole moment 0 and the difference between parallel and perpendicular components of the optical polarizability tensor. F o r CO 2 , this quantity was found to have the value — (9.1±0.5)x 10 -50 e.s.u. can be determined by other methods, but unfortunately the present uncertainty in this quantity is greater than that of the product. The most satisfactory value of a a 8 -a 1 is taken to be 2.2 x 10 -24 cm 3 , giving for the molecular quadrupole moment of CO 2 — 4.1 x 10 -26 e.s.u., the sign indicating that the oxygen atoms are negative with respect to the carbon atom. The role of the ‘ quadrupole polarizability ’ of the molecule in complicating the interpretation of the experimental results is discussed, and experiments on argon and sulphur hexafluoride used to provide an estimate of its effect in the case of CO 2 .

Kinetics of reactive absorption of carbon dioxide with solutions of aniline in carbon tetrachloride and chloroform

2008 ◽  
Vol 136 (2-3) ◽  
pp. 349-357 ◽  
Author(s):  
Srikanta Dinda ◽  
Anand V. Patwardhan ◽  
Swapna Rekha Panda ◽  
Narayan C. Pradhan
Keyword(s):  
Carbon Dioxide ◽  
Carbon Tetrachloride ◽  
Reactive Absorption ◽  
Kinetics Of

γ-Radiosensitized isomerization of gaseous butenes and methylbutenes

1980 ◽  
Vol 58 (18) ◽  
pp. 1973-1978 ◽  
Author(s):  
Guy J. Collin ◽  
Jan A. Herman
Keyword(s):  
Noble Gas ◽  
Chain Mechanism ◽  
Reverse Effect ◽  
A Chain

We have studied the isomerization of butenes and methylbutenes by noble gas-sensitized radiolysis. The isomerization of isobutene to but-2-ene is more efficient in the presence of xenon than in the presence of krypton or argon. The isomerization of but-1-ene into isobutene has a low radiolytic yield and occurs only in the presence of small quantities of dimethylamine. These observations are in agreement with the isomerization of the excited parent ion.In the methylbutene systems, whatever the sensitizing agent, isomerization occurs with a high radiolytic yield. Thus, a chain mechanism is needed to explain the results. The addition of dimethylamine has a reverse effect relative to that observed in but-1-ene. It is concluded that the mechanism invoked for the butene systems is not adequate for explaining the isomerization observed in the methylbutene systems.

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