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Title: Production of HCl in the OH + ClO reaction: Laboratory measurements and statistical rate theory calculations

Abstract

The branching ratio for the OH + ClO reaction has been measured using the turbulent flow technique with high-pressure chemical ionization mass spectrometry for the detection of reactants and products. In the earlier study, OD was used instead of OH due to the large HCl background produced by the ClO source. Improvements to the experimental technique have significantly reduced this HCl background, thus making it possible to observe directly the production of very small concentrations of HCl ({approximately}10{sup 9} molecule cm{+-}3) from the minor channel of the OH + ClO reaction. At room temperature and {approximately}100 Torr pressure, the rate constant for this minor channel was determined to be (9.5 {+-} 1.6) x 10{sup {minus}13} cm{sup 3} molecule{sup {minus}1} s{sup {minus}1} with a two standard deviation error limit, which remained unchanged when the pressure was increased to 200 Torr. The temperature dependence of the rate constant for this minor channel was also investigated between 207 and 298 K, and the data were fit to the following Arrhenius expression: (3.2 {+-} 0.8) x 10{sup {minus}13} exp[(325 {+-} 60)/T] cm{sup 3} molecule{sup {minus}1} s{sup {minus}1}. The branching ratio for the HCl channel was determined to be 0.07 {+-} 0.03 at all pressuresmore » and temperatures investigated in this study. Statistical rate theory calculations were also performed on the OH + ClO reaction system and are in good agreement with the experimental results.« less

Authors:
; ; ; ;
Publication Date:
Research Org.:
Massachusetts Inst. of Tech., Cambridge, MA (US)
OSTI Identifier:
20003183
Resource Type:
Journal Article
Journal Name:
Journal of Physical Chemistry A: Molecules, Spectroscopy, Kinetics, Environment, amp General Theory
Additional Journal Information:
Journal Volume: 103; Journal Issue: 33; Other Information: PBD: 19 Aug 1999
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; HYDROCHLORIC ACID; TURBULENT FLOW; HYDROXIDES; CHLORINE OXIDES; OZONE; STRATOSPHERE; ATMOSPHERIC CHEMISTRY

Citation Formats

Lipson, J.B., Beiderhase, T.W., Molina, L.T., Molina, M.J., and Olzmann, M. Production of HCl in the OH + ClO reaction: Laboratory measurements and statistical rate theory calculations. United States: N. p., 1999. Web. doi:10.1021/jp9847787.
Lipson, J.B., Beiderhase, T.W., Molina, L.T., Molina, M.J., & Olzmann, M. Production of HCl in the OH + ClO reaction: Laboratory measurements and statistical rate theory calculations. United States. doi:10.1021/jp9847787.
Lipson, J.B., Beiderhase, T.W., Molina, L.T., Molina, M.J., and Olzmann, M. Thu . "Production of HCl in the OH + ClO reaction: Laboratory measurements and statistical rate theory calculations". United States. doi:10.1021/jp9847787.
@article{osti_20003183,
title = {Production of HCl in the OH + ClO reaction: Laboratory measurements and statistical rate theory calculations},
author = {Lipson, J.B. and Beiderhase, T.W. and Molina, L.T. and Molina, M.J. and Olzmann, M.},
abstractNote = {The branching ratio for the OH + ClO reaction has been measured using the turbulent flow technique with high-pressure chemical ionization mass spectrometry for the detection of reactants and products. In the earlier study, OD was used instead of OH due to the large HCl background produced by the ClO source. Improvements to the experimental technique have significantly reduced this HCl background, thus making it possible to observe directly the production of very small concentrations of HCl ({approximately}10{sup 9} molecule cm{+-}3) from the minor channel of the OH + ClO reaction. At room temperature and {approximately}100 Torr pressure, the rate constant for this minor channel was determined to be (9.5 {+-} 1.6) x 10{sup {minus}13} cm{sup 3} molecule{sup {minus}1} s{sup {minus}1} with a two standard deviation error limit, which remained unchanged when the pressure was increased to 200 Torr. The temperature dependence of the rate constant for this minor channel was also investigated between 207 and 298 K, and the data were fit to the following Arrhenius expression: (3.2 {+-} 0.8) x 10{sup {minus}13} exp[(325 {+-} 60)/T] cm{sup 3} molecule{sup {minus}1} s{sup {minus}1}. The branching ratio for the HCl channel was determined to be 0.07 {+-} 0.03 at all pressures and temperatures investigated in this study. Statistical rate theory calculations were also performed on the OH + ClO reaction system and are in good agreement with the experimental results.},
doi = {10.1021/jp9847787},
journal = {Journal of Physical Chemistry A: Molecules, Spectroscopy, Kinetics, Environment, amp General Theory},
number = 33,
volume = 103,
place = {United States},
year = {1999},
month = {8}
}