Thermal decomposition of barium perchlorate

1969 ◽  
Vol 47 (16) ◽  
pp. 3031-3039 ◽  
Author(s):  
R. J. Acheson ◽  
P. W. M. Jacobs
Keyword(s):  
Thermal Decomposition ◽  
Ambient Pressure ◽  
Barium Chloride ◽  
Reaction Sequence ◽  
Chain Reaction ◽  
Gaseous Products ◽  
A Chain ◽  
Two Stages ◽  
Linear Period ◽  
Barium Perchlorate

The thermal decomposition of anhydrous barium perchlorate to barium chloride and oxygen has been studied by pressure measurements, or by weight loss, in vacuo, under the accumulated gaseous products (0–3 Torr oxygen), under dry air or nitrogen, and mixed with added barium chloride. The plots of fractional decomposition (α) against time (t) are complex, as would be expected for a reaction proceeding via unstable intermediates. The most pronounced features of the α(t) curves are an initial acceleratory period, which is succeeded by an approximately linear period and then, after a sharp break (reduction in rate), by a deceleratory period which conforms to the contracting-volume kinetic law. The latter stage is associated with the decomposition of barium chlorate and has an activation energy of 59 kcal/mole. The first two stages comprise the decomposition of perchlorate to chlorate with the approximate stoichiometry 3ClO4− = 2ClO3− + Cl− + 3O2. A chain reaction sequence, which involves O atoms as chain carriers, is proposed for these stages. The effect of the removal of products, of increasing the ambient pressure of inert gas, and of the addition of barium chloride, can all be explained on this model.

The thermal decomposition of aliphatic aldehydes

1963 ◽  
Vol 276 (1365) ◽  
pp. 278-292 ◽  
Keyword(s):  
Nitric Oxide ◽  
Thermal Decomposition ◽  
Chain Reaction ◽  
Chance Coincidence ◽  
Limited Success ◽  
Molecular Reaction ◽  
A Chain ◽  
The Stability ◽  
Oxide Inhibition ◽  
Chain Propagation And Termination

The thermal decomposition of acetaldehyde, propionaldehyde, n -butyraldehyde and iso-butyraldehyde, as investigated by the static method, is essentially homogeneous, inhibitable by propylene, isobutene and small amounts of nitric oxide, and generally catalyzed at high inhibitor concentrations. The kinetic order of the uninhibited decomposition exhibits little obvious regularity, but that of the maximally inhibited reaction is approximately 1.5 for all three inhibitors. Kates of the uninhibited decomposition do not follow the sequence in the homologous series, and there is no systematic variation in the extent of inhibition from one aldehyde to another. For each aldehyde, the minimum rates for the three inhibitors in general are not identical, nevertheless exhibit a correspondence probably close enough to eliminate chance coincidence. The kinetic and analytical results of the uninhibited decomposition can be approximately described by a Kice-Herzfeld-type mechanism, with the kinetics in each case largely determined by the stability of radicals and their reactions in chain propagation and termination. The question whether the maximally inhibited reaction is a molecular reaction or a chain reaction is surveyed. Although the results cannot be completely accounted for by a molecular reaction alone, a chain mechanism for propylene inhibition involving allyl radicals likewise has only limited success. For nitric-oxide inhibition, it is not certain how far the results are affected by the occurrence of the subsequent catalyzed reaction. No definite conclusion can thus be reached about the nature of the maximally inhibited reaction.

scholarly journals The thermal decomposition of acetaldehyde

1935 ◽  
Vol 149 (867) ◽  
pp. 355-359 ◽  
Keyword(s):  
Thermal Decomposition ◽  
Carbon Monoxide ◽  
Condensation Reaction ◽  
Pressure Increase ◽  
Chain Mechanism ◽  
Vessel Size ◽  
Previous Evidence ◽  
Gaseous Products ◽  
A Chain ◽  
Effect Of Surface

This paper contains a more detailed study than has hitherto been made of the effect of surface and vessel size on the thermal decomposition of acetaldehyde. This was desirable in view of the suggestion recently made that the reaction might take place by a chain mechanism, and also because the validity of the previous evidence that the reaction is homogeneous has been called in question. In an unpacked silica between 500° and 600° the reaction is attended by a pressure increase which is about 98% of that corresponding to the equation CH 3 CHO = CH 4 + CO, and the gaseous products consists of equal parts of carbon monoxide and methane. When a packed vessel with very large surface is used the pressure increase is rather less than the theoretical, indicating that some condensation reaction occurs which is probably heterogeneous in contrast with the principal decomposition.

Cracking of squalene into isoprene as chemical utilization of algae oil

2020 ◽  
Vol 22 (10) ◽  
pp. 3083-3087
Author(s):  
Kazuya Kimura ◽  
Kazuma Shiraishi ◽  
Takahiro Kondo ◽  
Junji Nakamura ◽  
Tadahiro Fujitani
Keyword(s):  
Thermal Decomposition ◽  
Chain Reaction ◽  
Algae Oil ◽  
A Chain ◽  
Chemical Utilization

Thermal decomposition of squalene proceeds as a chain reaction to produce isoprene (C5H8) and C10 hydrocarbons.

THE KINETICS OF THE THERMAL DECOMPOSITION OF DISULPHUR DECAFLUORIDE

1951 ◽  
Vol 29 (6) ◽  
pp. 508-525 ◽  
Author(s):  
W. R. Trost ◽  
R. L. McIntosh
Keyword(s):  
Nitric Oxide ◽  
Thermal Decomposition ◽  
Heterogeneous Reaction ◽  
Homogeneous Reaction ◽  
Chain Reaction ◽  
First Order ◽  
Reaction Proceeds ◽  
Total Process ◽  
A Chain ◽  
Kinetics Of

The thermal decomposition of the gas disulphur decafluoride has been studied in a metal reactor. Analytical evidence showed that the reaction proceeds according to the equation S2F10 = SF6 + SF4.The reaction was found to be largely homogeneous, as the heterogeneous reaction accounted for less than 5% of the total process. The homogeneous reaction was shown to be first order, and in the temperature range investigated the rate is given by ln k = 47.09 − 49,200/RT. A chain reaction is postulated to explain the observed rate of the reaction. The effect of nitric oxide and acetylene dichloride on the rate and products of the reaction was investigated.

Kinetic Studies in the Chemistry of Rubber and Related Materials. II. The Kinetics of Oxidation of Unconjugated Olefins

1947 ◽  
Vol 20 (3) ◽  
pp. 609-617 ◽  
Author(s):  
J. L. Holland ◽  
Geoffrey Gee
Keyword(s):  
Thermal Decomposition ◽  
Kinetic Studies ◽  
Chain Termination ◽  
Low Oxygen ◽  
Chain Reaction ◽  
Kinetics Of Oxidation ◽  
Chain Initiation ◽  
A Chain ◽  
Kinetics Of ◽  
Direct Attack

Abstract A brief review is given of kinetic work on the oxidation of representative mono, 1,4 and 1,5 olefins. The essential process in each case is identified as a chain reaction in which hydrocarbon radicals are formed, absorb oxygen, and then react with another molecule of olefin to give a hydroperoxide and a new free radical. Three methods of chain initiation are considered: (1) direct attack of oxygen on the olefin, (2) thermal decomposition of the hydroperoxide, (3) thermal decomposition of added benzoyl peroxide. Chain termination results from interaction of two free radicals; except at low oxygen pressures, these are both peroxidic.

scholarly journals A study of the chain reaction in the thermal decomposition of diethyl ether.

1938 ◽  
Vol 167 (931) ◽  
pp. 456-463 ◽  
Author(s):  
J. E. Hobbs ◽  
Cyril Norman Hinshelwood
Keyword(s):  
Thermal Decomposition ◽  
Diethyl Ether ◽  
Reaction Rate ◽  
Initial Rate ◽  
Intramolecular Rearrangement ◽  
Chain Mechanism ◽  
Chain Reaction ◽  
Experimental Conditions ◽  
Rearrangement Process ◽  
A Chain

In a recent paper (Hobbs and Hinshelwood 1938), information about the chain mechanisms involved in the thermal decomposition of ethane was obtained by studying the variation with the ethane concentration of the shape of the curve which represents in the reaction rate as a function of minute quantities of added nitric oxide. This paper describes the results of a similar investigation carried out with diethyl ether, the behaviour of which shows an interesting contrast with that of ethane. The thermal decomposition of diethyl ether in the neighbourhood of 500° C. occurs partly by a chain mechanism in which free radicals are formed, and partly by intramolecular rearrangement (Staveley and Hinshelwood 1936, 1937). The end- products of the decomposition are methane, ethane, and carbon monoxide, with small amounts of hydrogen and unsaturated substances. Acetaldehyde is an intermediate product formed either in the rearrangement process, or, as in the mechanism put formed below, during the chain reaction (Fletcher and Rollefson 1936). The acetaldehyde, however, decomposes rapidly under the experimental conditions and the initial rate is sensibly that of the decomposition of the ether into final products.

MTBE degradation by hydrodynamic induced cavitation

2010 ◽  
Vol 61 (10) ◽  
pp. 2591-2594 ◽  
Author(s):  
A. Schmid
Keyword(s):  
Energy Demand ◽  
Ambient Pressure ◽  
Ultrasound Irradiation ◽  
Hydrodynamic Cavitation ◽  
Chain Reaction ◽  
Cavitation Bubbles ◽  
Water Constituents ◽  
A Chain ◽  
Mtbe Degradation ◽  
Pilot Tests

Hydrodynamic induced cavitation generates imploding cavitation bubbles which can lead to degradation or even mineralisation of water constituents without addition of any chemicals. This technology overcomes the problems of ultrasound irradiation by the local production of a cavitation cloud close to the sonotrodes. Hydrodynamic cavitation can be stabilised downstream of the nozzle depending on the ambient pressure conditions. If the pressure is kept low, the imploding cavitation bubbles generate new cavities, analogous to a chain reaction, and elevate the radical synthesis inside the apparatus. During the pilot tests MTBE and ETBE were degraded and complete mineralisation started at a time delay of app. 30 min. The specific energy demand for MTBE degradation lies in the range of app. 200 Wh/ppm in the investigated concentration range of about 30 ppm.

Observations on a Relationship between Steroid Metabolism and the Concentration of Plasma Fibrinogen

1963 ◽  
Vol 10 (02) ◽  
pp. 400-405 ◽  
Author(s):  
B. A Amundson ◽  
L. O Pilgeram
Keyword(s):  
Blood Coagulation ◽  
Methyl Ether ◽  
Broad Spectrum ◽  
Human Subjects ◽  
Plasma Fibrinogen ◽  
Steroid Metabolism ◽  
Specific Site ◽  
Chain Reaction ◽  
Normal Human ◽  
A Chain

SummaryEnovid (5 mg norethynodrel and 0.075 mg ethynylestradiol-3-methyl ether) therapy in young normal human subjects causes an increase in plasma fibrinogen of 32.4% (P >C 0.001). Consideration of this effect together with other effects of Enovid on the activity of specific blood coagulatory factors suggests that the steroids are exerting their effect at a specific site of the blood coagulation and/or fibrinolytic system. The broad spectrum of changes which are induced by the steroids may be attributed to a combination of a chain reaction and feed-back control.

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