Flash photolysis of H2S

Abstract

Hydrogen atoms produced by flash photolysis of H₂S are “hot” and react with CO₂ by process (13). H + CO₂→CO + OH, ΔH= 102 kJ mol^–1(13)

Flash spectroscopy has been used to determine [SH] and [S₂] as functions of time following flash photolysis of H₂S diluted with CO₂. The rate-determining step in the decay of SH is either (3) or (4), with k₃= 1 × 10^–11 or k₄= 3 × 10^–11 cm³ molecule^–1 s^–1. The removal of S₂ occurs principally by reaction (8), which is third order over the range of pressures studied, and the order of magnitude of k₈ is 2.5 × 10^–30 cm⁶ molecule^–2 s^–1. H + SH→H₂+ S (3), 2SH→H₂S + S (4), 2S₂+ CO₂→S₄+ CO₂. (8)