Gas-phase photolysis of hydrogen iodide. Part 3.—Hot atom effects

Abstract

The effects of He, H₂ and Ar as hot atom moderators in the photolysis of hydrogen iodide in the 2537 Å region of the mercury emission have been studied. The rate constant ratio k₃/k₂ for reactions H + HI → H₂+ I; H + I₂→ HI + I has been determined for thermally equilibrated H atoms and has a value 12.0 ± 1 in the temperature range 50–200°C. This result agrees with a value estimated from the thermal hydrogen iodide synthesis.