The thermal decomposition of n-propyl bromide

1968 ◽  
Vol 21 (4) ◽  
pp. 973 ◽  
Author(s):  
JTD Cross ◽  
VR Stimson
Keyword(s):  
Thermal Decomposition ◽  
Rate Constant ◽  
Hydrogen Bromide ◽  
Bromine Atom ◽  
Order Reaction ◽  
Chain Mechanism ◽  
Initial Concentration ◽  
First Order ◽  
Reaction Proceeds ◽  
Atom Chain

Mechanisms already proposed or formally possible for the decomposition of n-propyl bromide as a 312-order reaction are shown to be unsatisfactory, and the reaction has been reinvestigated. Two reactions occur simultaneously: (a) a first-order reaction identifiable with the maximally inhibited reaction and presumably molecular; (b) a reaction second order in the initial concentration and somewhat autocatalysed as the reaction proceeds. The rate constant is given by k2 == 1018.1exp(-49300/RT)sec-1ml mole-1 Reaction (b) is catalysed by hydrogen bromide and inhibited by propene, and a bromine atom chain mechanism with hydrogen bromide catalysed initiation is proposed. Bromine-catalysed decomposition has also been studied. The mechanism of the inhibition is discussed.

The thermal decomposition of trimethylacetyl bromide

1970 ◽  
Vol 23 (3) ◽  
pp. 525 ◽  
Author(s):  
BS Lennon ◽  
VR Stimson
Keyword(s):  
Thermal Decomposition ◽  
Carbon Monoxide ◽  
Hydrogen Bromide ◽  
Transition States ◽  
Volume Ratio ◽  
Reaction Vessel ◽  
Chain Mechanism ◽  
Radical Chain ◽  
First Order ◽  
Polar Transition

Trimethylacetyl bromide decomposes at 298-364� into isobutene, carbon monoxide, and hydrogen bromide in a first-order manner with rate given by k1 = 138 x 1014exp(-48920/RT) sec-1 The rate is unaffected by addition of the products or of inhibitors, or by increase of the surface/volume ratio of the reaction vessel. The likely radical chain mechanism is considered and rejected. The reaction is believed to be a molecular one, and possible cyclic and polar transition states are discussed.

scholarly journals Determination of exothermic batch reactor specific model parameters

2019 ◽  
Vol 292 ◽  
pp. 01063
Author(s):  
Lubomír Macků
Keyword(s):  
Rate Constant ◽  
Reaction Rate ◽  
Batch Reactor ◽  
Specific Model ◽  
Reaction Rate Constant ◽  
Order Reaction ◽  
First Order Reaction ◽  
Model Parameters ◽  
Reactor Model ◽  
First Order

An alternative method of determining exothermic reactor model parameters which include first order reaction rate constant is described in this paper. The method is based on known in reactor temperature development and is suitable for processes with changing quality of input substances. This method allows us to evaluate the reaction substances composition change and is also capable of the reaction rate constant (parameters of the Arrhenius equation) determination. Method can be used in exothermic batch or semi- batch reactors running processes based on the first order reaction. An example of such process is given here and the problem is shown on its mathematical model with the help of simulations.

THE THERMAL DECOMPOSITION OF PERACETIC ACID IN AROMATIC SOLVENTS

1963 ◽  
Vol 41 (7) ◽  
pp. 1826-1831 ◽  
Author(s):  
F. W. Evans ◽  
A. H. Sehon
Keyword(s):  
Thermal Decomposition ◽  
Rate Constant ◽  
Peracetic Acid ◽  
First Order ◽  
Aromatic Solvents ◽  
Temperature Range ◽  
Polymeric Compounds

The thermal decomposition of peracetic acid in toluene, benzene, and p-xylene was studied over the temperature range 75–95°C. The main products of decomposition were found to be CH4, CO2, CH3COOH; small amounts of methanol, phenols, and polymeric compounds were also detected.The rate of the overall decomposition was first order with respect to peracetic acid, and the results could be explained by postulating the participation of the two simultaneous reactions:[Formula: see text] [Formula: see text]The rate constant of reaction (1) was independent of the solvent, whereas k2 was dependent on the solvent. The ratio k2/k1 was about 10.

Substituent effects of rate constants for thermal [4π + 2π] cycloreversion of spiro-fused β-lactam oxadiazolines

1993 ◽  
Vol 71 (6) ◽  
pp. 907-911 ◽  
Author(s):  
Michel Zoghbi ◽  
John Warkentin
Keyword(s):  
Thermal Decomposition ◽  
Rate Constant ◽  
Rate Constants ◽  
Transition States ◽  
Substituent Effects ◽  
Ground States ◽  
Phenyl Substituent ◽  
First Order ◽  
Average Value ◽  
Carbonyl Ylide

Twelve Δ3-1,3,4-oxadiazolines in which C-2 is also C-4 of a β-lactam moiety (spiro-fused β-lactam oxadiazoline system) were thermolyzed as solutions in benzene. Substituents in the β-lactam portion affect the rate constant for thermal decomposition of the oxadiazolines to N2, acetone, and a β-lactam-4-ylidene. The total spread of first-order rate constants at 100 °C was 47-fold and the average value was 6.7 × 10−4 s−1. A phenyl substituent at N-1 or at C-3 was found to be rate enhancing, relative to methyl. At C-3, H and Cl were also rate enhancing, relative to methyl. The data are interpreted in terms of the differential effects of substituents on the stabilities of the ground states, and on the stabilities of corresponding transition states for concerted, suprafacial, [4π + 2π] cycloreversion. The first products, presumably formed irreversibly, are N2 and a carbonyl ylide. The latter subsequently fragments to form acetone (quantitative) and a β-lactam-4-ylidene.

Enhancement of decomposition of 2-chlorophenol with ultrasound/H2O2 process

1996 ◽  
Vol 34 (9) ◽  
pp. 41-48 ◽  
Author(s):  
Jih-Gaw Lin ◽  
Cheng-Nan Chang ◽  
Jer-Ren Wu ◽  
Ying-Shih Ma
Keyword(s):  
Ionic Strength ◽  
Reaction Rate ◽  
Order Reaction ◽  
Pseudo First Order Reaction ◽  
Initial Concentration ◽  
First Order ◽  
Toc Removal ◽  
Cp Decomposition ◽  
Effects Of Ph ◽  
Pseudo First Order

We investigated the effects of pH, ionic strength, catalyst, and initial concentration on both decomposition of 2-chlorophenol (2-cp) and removal of total organic carbon (TOC) in aqueous solution with ultrasonic amplitude 120 μm and H2O2 (200 mg/l). When the initial concentrations of 2-cp was 100 mg/l and the pH was controlled at 3, the rate of 2-cp decomposition was enhanced up to 6.6-fold and TOC removal up to 9.8-fold over pH controlled at 11. At pH 3, the efficiency of decomposition of 2-cp was 99% but the removal of TOC was only 63%; a similar situation applied at pH 7 and 11. Hence intermediate compounds were produced and 2-cp was not completely mineralized. When the concentration of ionic strength was increased from 0.001 to 0.1 M, the rate of 2-cp decomposition was enhanced only 0.3-fold, whereas the TOC removal was not enhanced. In comparison of the effects of pH and ionic strength, pH had greater influence on both 2-cp decomposition and TOC removal than ionic strength. The effect of a catalyst (FeSO4) on decomposition of 2-cp was insignificant comparing with direct addition of H2O2. The reaction rate at a smaller initial concentration of 2-cp (10 mg/l) was more rapid than at a greater one (100 mg/l). The rate of 2-cp decomposition and TOC removal appeared to follow pseudo-first-order reaction kinetics.

The thermal decomposition of cyclobutane-1,2-dione

1985 ◽  
Vol 63 (11) ◽  
pp. 2945-2948 ◽  
Author(s):  
J.-R. Cao ◽  
R. A. Back
Keyword(s):  
Activation Energy ◽  
Thermal Decomposition ◽  
Vapor Pressure ◽  
Gas Phase ◽  
Rate Constant ◽  
Surface Reaction ◽  
Order Rate Constant ◽  
Reaction Vessel ◽  
Arrhenius Parameters ◽  
First Order

The thermal decomposition of cyclobutane-1,2-dione has been studied in the gas phase at temperatures from 120 to 250 °C and pressures from 0.2 to 1.5 Torr. Products were C2H4 + 2CO, apparently formed in a simple unimolecular process. The first-order rate constant was strongly pressure dependent, and values of k∞ were obtained by extrapolation of plots of 1/k vs. 1/p to1/p = 0. Experiments in a packed reaction vessel showed that the reaction was enhanced by surface at the lower temperatures. Arrhenius parameters for k∞, corrected for surface reaction, were log A (s−1) = 15.07(±0.3) and E = 39.3(±2) kcal/mol. This activation energy seems too low for a biradical mechanism, and it is suggested that the decomposition is probably a concerted process. The vapor pressure of solid cyclobutane-1,2-dione was measured at temperatures from 22 to 62 °C and a heat of sublimation of 13.1 kcal/mol was estimated.

The formation of O2(a1Δg) in homogeneous and heterogeneous atom recombination

1986 ◽  
Vol 64 (12) ◽  
pp. 1614-1620 ◽  
Author(s):  
A. A. Ali ◽  
E. A. Ogryzlo ◽  
Y. Q. Shen ◽  
P. T. Wassell
Keyword(s):  
Kinetic Study ◽  
Gas Phase ◽  
Molecular Oxygen ◽  
Rate Constant ◽  
Room Temperature ◽  
High Efficiency ◽  
Flow System ◽  
Order Reaction ◽  
Third Order ◽  
First Order

The recombination of oxygen atoms has been studied in a discharge flow system at room temperature. The yield of O2(a1Δg) in the recombination on Pyrex has been found to be 0.08 (±0.02). In the gas phase, O2(a) was found to be formed in a process that is second order in [O] and first order in [N2]. The rate constant for this third-order reaction was found to be 3.4 (±0.4) × 10−34 cm6∙molecule−2∙s−1, representing a yield of 0.07 (±0.02). In the presence of molecular oxygen, the rate of production of O2(a) was found to increase. A kinetic study of this effect led to the conclusion that collisions of molecular oxygen with an unidentified precursor can produce O2(a) with high efficiency.

Nucleophilic attack on the carbon–carbon double bond. I. Reaction of primary and secondary amines with 2,2-di(4-nitrophenyl)-1,1-difluoroethene

1986 ◽  
Vol 64 (12) ◽  
pp. 2274-2278 ◽  
Author(s):  
Kenneth T. Leffek ◽  
Urszula Maciejewska
Keyword(s):  
Order Reaction ◽  
Secondary Amines ◽  
Nucleophilic Attack ◽  
Ammonium Ions ◽  
Third Order ◽  
First Order ◽  
Enthalpy Of Activation ◽  
Catalysed Reaction ◽  
Primary And Secondary Amines ◽  
Reaction Proceeds

The reaction of primary and secondary amines with 2,2-di(4-nitrophenyl)-1,1-difluoroethene (1) in acetonitrile solvent gives first 2,2-di(4-nitrophenyl)-1-fluoro-1-aminoethene (2) and then 2,2-di(4-nitrophenyl)-1,1-difluoro-1-aminoethane (3). With excess amine, pseudo-first-order rate constants for the production of 2 were measured, which showed a second-order reaction, together with a catalysed third-order reaction. In addition to the reagent amines, the reaction is also catalysed by tertiary amines and bases such as oxalate and acetate, but not by chloride and perchlorate, nor by ammonium ions. The enthalpy of activation for the reaction of piperidine with 1 in acetonitrile is 3.7 kcalmol−1, but for the catalysed reaction an apparent value of −2.2 kcal mol−1 was obtained. It is concluded that the reaction proceeds via a pre-equilibrium to a zwitterion, followed by another equilibrium giving a carbanion that yields the product (2) by a rate-determining cleavage of the carbon–fluorine bond.

Electrochemical Degradation of RDX in Aqueous Solution at Constructed Sb-Doped SnO2 Anode

2011 ◽  
Vol 396-398 ◽  
pp. 1803-1806
Author(s):  
Yong Chen ◽  
Lei Hong ◽  
Wei Shi ◽  
Wei Qing Han ◽  
Lian Jun Wang
Keyword(s):  
Aqueous Solution ◽  
Current Density ◽  
Order Reaction ◽  
Electrochemical Degradation ◽  
Kinetics Analysis ◽  
Pseudo First Order Reaction ◽  
Initial Concentration ◽  
First Order ◽  
Sno2 Electrode ◽  
Pseudo First Order

The constructed Sb-doped SnO2 electrode was obtained for electrochemical degradation of RDX. The influences of current density and initial concentration of RDX on electrochemical degradation of RDX were studied. Kinetics analysis shows that the electrochemical degradation of RDX follows the pseudo first-order reaction. The mechanism of electrochemical degradation of RDX was also discussed.

THE DECOMPOSITION OF SILYL PEROXIDES

1964 ◽  
Vol 42 (5) ◽  
pp. 985-989 ◽  
Author(s):  
Richard R. Hiatt
Keyword(s):  
Thermal Decomposition ◽  
Rate Constant ◽  
Half Life ◽  
Order Rate Constant ◽  
Butyl Alcohol ◽  
Base Catalysis ◽  
First Order ◽  
Tert Butyl ◽  
Tert Butyl Alcohol ◽  
Acid And Base

The thermal decomposition of tert-butyl trimethylsilyl peroxide has been investigated and found to be sensitive to acid and base catalysis and to the nature of the solvent. In heptane and iso-octane the first-order rate constant could be expressed as 1.09 × 1015e−41200/RT and in 1-octene as 3.90 × 1015e−41200/RT (sec−1). The half life at 203 °C was about 1 hour. The reaction was faster in aromatic solvents; in chlorobenzene it was complicated by formation of HCl from the solvent.Products of the reaction were acetone, tert-butyl alcohol and hexamethyldisiloxane.

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