Abstract: | The reactions of Cl and Br atoms with H2O2 have been studied in the range of 300–350 K using the very-low-pressure-reactor technique. It was found that metathesis to produce HX and HO2 is the only significant process (≤99%). For the reaction of Br k2 (300 K) = 1.3 ± 0.45 × 10?14 and k2 (350 K) = 3.75 ± 1.1 × 10?14 cm3/molecules·s, with an activation energy of 4.6 ± 0.7 kcal/mol. Using an estimated A factor for A2, we find suggesting that a best choice is E2 = 3.9 ± 0.4 kcal/mol. The relation of these values to ΔH (HO2) is discussed. |