✦ LIBER ✦

Kinetics and thermochemistry of the methyl radical: Study of the CH3 + HCl reaction

✍ Scribed by John J. Russell; Jorma A. Seetula; Selim M. Senkan; David Gutman

Publisher: John Wiley and Sons
Year: 1988
Tongue: English
Weight: 754 KB
Volume: 20
Category: Article
ISSN: 0538-8066
DOI: 10.1002/kin.550201002

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✦ Synopsis

The kinetics of the reaction between CH3 and HCI was studied in a tubular reactor coupled to a photoionization mass spectrometer. Rate constants were measured as a function of temperature (296-495 K) and were fitted to an Arrhenius expression: kl = 5.0(+-0.7) x exp{-1.4(+0.3) kcal mol-'/RT} cm3 molecule-' s-'. This information was combined with known kinetic parameters of the reverse reaction to obtain Second Law determinations of the methyl radical heat of formation {34.7(+0.6) kcal mol-'} and entropy {46(?-23 cal mo1-l K-'} a t 298 K. Using the known entropy of CH,, a more accurate Third Law determination of the CH, heat of formation a t this temperature was also obtained {34.8( 20.3) kcal mol-'}. The values of k1 obtained in this study are between those reported in prior investigations. The results were also used to test the accuracy of the thermochemical information which can be obtained from kinetic studies of R + HX (X = CI, Br, I) reactions of the type described here.

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