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Rate constants for the reactions of OH with CH3Cl, CH2Cl2, CHCl3, and CH3BrRate constants for the reactions of OH with CH3Cl, CH2Cl2, CHCl3, and CH3Br have been measured by a relative rate technique in which the reaction rate of each compound was compared to that of HFC-152a (CH3CHF2) and (for CH2Cl2) HFC-161 (CH3CH2F). Using absolute rate constants for HFC-152a and HFC-161, which we have determined relative to those for CH4, CH3CCl3, and C2H6, temperature dependent rate constants of both compounds were derived. The derived rate constant for CH3Br is in good agreement with recent absolute measurements. However, for the chloromethanes all the rate constants are lower at atmospheric temperatures than previously reported, especially for CH2Cl2 where the present rate constant is about a factor of 1.6 below the JPL 92-20 value. The new rate constant appears to resolve a discrepancy between the observed atmospheric concentrations and those calculated from the previous rate constant and estimated release rates.
Document ID
19950035276
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Hsu, K.-J. (Jet Propulsion Laboratory, California Inst. of Tech., Pasadena, CA United States)
Demore, W. B. (Jet Propulsion Laboratory, California Inst. of Tech., Pasadena, CA United States)
Date Acquired
August 16, 2013
Publication Date
May 1, 1994
Publication Information
Publication: Geophysical Research Letters
Volume: 21
Issue: 9
ISSN: 0094-8276
Subject Category
ENVIRONMENT POLLUTION
Distribution Limits
Public
Copyright
Other