Reactions of atomic hydrogen and deuterium with hydrobromic acid and hydrobromic acid-d

The reactions H + HBr, D + HBr, H + DBr, and D + DBr have been studied directly over the temperature range 230-318/sup 0/K using a discharge flow apparatus equipped for EPR detection of atoms. Absolute rate constants of (2.77 +- 0.32) x 10/sup -10/ exp (-(2570 +- 110)/RT), (6.40 +- 0.57) x 10/sup -11/ exp (-(2130 +- 80)/RT), (1.09 +- 0.08) x 10/sup -10/ exp (-(2190 +- 110)RT), and (2.27 +- 0.21) x 10/sup -11/ exp (-(1690 +- 130)/RT) cm/sup 3/ molecule/sup -1/ s/sup -1/ were obtained for the reactions H + HBr, D + HBr, H + DBr, and D + DBr, respectively. At 295/sup 0/K, rate constants for the exchange reactions H + DBr ..-->.. D + HBr and D + HBr ..-->.. H + DBr were measured as less than or equal to 3.9 x 10/sup -14/ and 1.3 +- 0.4 x 10/sup -14/ cm/sup 3/ molecule/sup -1/ s/sup -1/, respectively.