摘要:

AbstractIt is a useful feature of many general chemical kinetics programs that the user's reaction scheme is tested as far as possible before a calculation is started. Attempts are made to answer the question: How far can a reaction scheme be tested for consistency, with respect to mass conservation, without knowing the molecular weights of the species involved? It is found that this problem can be transformed so that it is solvable by the standard methods used in linear programming.

ISSN:0538-8066    

DOI:10.1002/kin.550120802

出版商:John Wiley&Sons, Inc.    

年代:1980

数据来源: WILEY

摘要:

AbstractThe oxidations of ferrocene (FcH) andn‐butylferrocene (FcBu) by ferric salts (nitrate or bromide) are strongly inhibited by aqueous cetyltrimethylammonium bromide and nitrate (CTABr and CTANO3, respectively). The kinetics of inhibition fit a model in which the substrates are distributed between water, and the micelles and binding constantsKsto the micelle can be estimated. The oxidations are strongly catalyzed by micelles of sodium lauryl sulfate (NaLS), and the kinetics can be fitted to a model in which the reaction rate depends upon the concentration of both reactants in the micellar pseudophase and the rate constants in that pseudophase, which for both substrates are very similar to those in water. Some added salts reduce the micellar catalysis by excluding ferric ions from the micelle. The oxidations of FcH and FcBu by ferricyanide ions are too fast to be followed in water, but they are inhibited by anionic micelles of NaLS. By analyzing the rate surfactant profiles using independently measured values ofKsthe second‐order rate constants in water have been estima

ISSN:0538-8066    

DOI:10.1002/kin.550120803

出版商:John Wiley&Sons, Inc.    

年代:1980

数据来源: WILEY

摘要:

AbstractThe reaction of carbon monoxide with ozone was studied in the range of 75–160°C in the presence of varying amounts of CO2and, for a few experiments, of O2. At room temperature the reaction was immeasurably slow, but in a flow system it showed chemiluminescence with undamped oscillations. In a static system above 75°C the emission showed damped oscillations when O2was present. In the absence ofadded O2the emission showed a slow decay with a half‐life of 1 hr. The luminescence consisted of partially resolved bands in the range of 325–600 nm, and the source was identified as CO2(1B2) → CO2(1Σg+) +hv. The kinetics were complex, and the observed rate law could be accounted for bya mechanism involving the chain sequence\documentclass{article}\pagestyle{empty}\begin{document}$ {\rm O(}^{\rm 3} P{\rm ) + CO( + M)}\mathop {{\rm rightarrow}}\limits^{\rm 3} {\rm CO}_{\rm 2} {\rm (}^{\rm 3} B_{\rm 2} {\rm ) ( + M), CO}_{\rm 2} {\rm (}^{\rm 3} B_{\rm 2} {\rm ) + O}_{\rm 3} {\rm }\mathop {{\rm rightarrow}}\limits^{\rm 7} {\rm CO}_{\rm 2} {\rm (}^{\rm 1} \sum\nolimits_{\rm g}^{\rm + } {} {\rm ) + O}_{\rm 2} {\rm + O} $\end{document}. From measurements of ‐d[O3]/dtand relative emission, rate constant ratios were obtained and estimates o

ISSN:0538-8066    

DOI:10.1002/kin.550120804

出版商:John Wiley&Sons, Inc.    

年代:1980

数据来源: WILEY

摘要:

AbstractThe reaction NO + O3→ NO2+ O2has been studied in a 220‐m3spherical stainless steel reactor under stopped‐flow conditions below 0.1 mtorr total pressure. Under the conditions used, the mixing time of the reactants was negligible compared with the chemical reaction time. The pseudo‐first‐order decay of the chemiluminescence owing to the reaction of ozone with a large excess of nitric oxide was measured with an infrared sensitive photomultiplier. One hundred twenty‐nine decays at 18 different temperatures in the range of 283–443 K were evaluated. A weighted least‐squares fit to the Arrhenius equation yieldedk= (4.3 ± 0.6) × 10−12exp[‐(1598 ± 50)/T] cm3/molecule sec (two standard deviations in brackets). The Arrhenius plot showed no curvature within experimental accuracy. Comparison with recent results of Birks and co‐workers, however, suggests that a nonlinear fit, as proposed by these authors, is more appropriate over an ex

ISSN:0538-8066    

DOI:10.1002/kin.550120805

出版商:John Wiley&Sons, Inc.    

年代:1980

数据来源: WILEY

摘要:

AbstractThe kinetics of the pyrolysis of pyridine was studied in the temperature range of 875–1050°C, at 1 atm total pressure, in a Vycor stirred‐flow reactor. Initial concentrations ranged from 0.25 to 2 mol % in helium and reaction times from 0.25 to 4 sec. It was found at the lower temperatures that the reaction was mixed first and second order. At the higher temperatures an autocatalytic term, zero order in the substrate and first order in the concentration of pyridine decomposed, was necessary in addition to the other two terms to describe the kinetic data. Most of the product was in the form of a primarily aromatic, nonvolatile tar; the major volatile products were HCN and C2H2. An increase in the surface‐to‐volume ratio of the reactor decreased the rate, indicating a radical chain or sequential reaction with radical consumption on the surface. Experiments with additives showed that C2H2increased the rate. Using the kinetic and product data, some mechanistic considerations are discussed, and a mechanism is proposed to account for the first‐

ISSN:0538-8066    

DOI:10.1002/kin.550120806

出版商:John Wiley&Sons, Inc.    

年代:1980

数据来源: WILEY

摘要:

AbstractThe rate of HCN evolution during the inert pyrolysis of pyridine in the temperature range of 900–1000°C was determined in a flow system using a stirred‐flow reactor. The data indicated that HCN was formed through a sequence of reactions rather than during the initial step(s) involving the disappearance of pyridine. The Arrhenius parameters for the first‐order step yielding HCN were 39.5 kcal/mol and 6.8 for the activation energy and log frequency factor, respectively. The mechanistic implications of the rate data are discussed, and these are related to the overall pyridine pyrolysis mec

ISSN:0538-8066    

DOI:10.1002/kin.550120807

出版商:John Wiley&Sons, Inc.    

年代:1980

数据来源: WILEY

ISSN:0538-8066    

DOI:10.1002/kin.550120801

出版商:John Wiley&Sons, Inc.    

年代:1980

数据来源: WILEY