ISSN:
0538-8066
Keywords:
Chemistry
;
Physical Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Study of the thermal decomposition of propane at very low conversions in the temperature range 760-830 K led to refinement of the mechanism of the reaction.The quotient VCH4 + C2H4/VH2 + C3H6 characterizing the two decomposition routes connected with the 1- and 2-propyl radicals proved to depend linearly on the initial propane concentration. This suggested the occurrence of intermolecular radical isomerization: in competition with decomposition of the 2-propyl radical: The linearity led to the conclusion that the selectivity of H-abstraction from the methyl and methylene groups by the methyl radical is practically the same as that by the H atom. The temperature-dependence of this selectivity ( μ = kCH3/kCH2) was given by\documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm \mu = }\frac{{k_3 }}{{k_4 }} = \frac{{k_1 }}{{k_2 }} = 10^{0.26 \pm 0.03} \exp ( - 7.24 \pm 0.45{\rm kJ mol}^{{\rm - 1}} /RT). $$\end{document} Further evaluation of the dependence gave the Arrhenius representation \documentclass{article}\pagestyle{empty}\begin{document}$$ \frac{{k_7 }}{{k_6 }} = 10^{ - 5.97 \pm 0.03} \exp (115 \pm 5.1{\rm kJ mol}^{{\rm - 1}} /RT){\rm mol}^{{\rm - 1}} {\rm dm}^{\rm 3} $$\end{document} for the ratio of the rate coefficients of the above isomerization and decomposition reactions.Steady-state treatment resulted in the rate equation of the process, comparison of which with measurements gave further Arrhenius dependences.
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/kin.550180208
