Temperature dependence of rate constants for the reaction of atomic oxygen with hydrogen chloride

A phase-shift method has been used to determine the rate constant for the reaction of ground state oxygen atoms with HCl over the temperature range of 330–600 K. Oxygen atoms were generated by modulated mercury photosensitized decomposition of N₂O, and monitored by the chemiluminescence from their reaction with NO. After correction for diffusion of oxygen atoms from the viewing zone, the rate constants can be represented by the Arrhenius equation k₁ = (3.06 ± 1.43) × 10¹² exp(?3160 ± 184)/T] cm³/mol·s. The indicated uncertainties are 95% confidence limits for 15 degrees of freedom. Also, the third-body efficiency of HCl relative to N₂O in the reaction O + NO + M ← NO₂ + M was determined to be 1.9 ± 0.2 over the temperature range of 298–360 K.