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 conservation is found to be 97 +/- 3% for the overall chemical change in the system. 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 steady-state flow conditions in the VLPR system.