The kinetics of reaction Cl + HBr -->/1 HCl (v) + Br have been studied
at 298 K using the very low pressure reactor (VLPR). k(1) = (6.16 +/-
0.07) x 10(-12) cm(3)/(molecule s), Calculated from both the reactant
consumption and Br product formation rate measurements. Mass conserva
tion is found to be 97 +/- 3% for the overall chemical change in the s
ystem. Calculations using known relaxation rates for HCl (v) show that
vibrationally excited products of either HCl (v=2) or HBr (v=1) have
no measurable contribution to the kinetics of reaction 1 under the ste
ady-state flow conditions in the VLPR system.