Kinetics of the Reactions of Oxygen Atoms and Nitrogen Atoms with Sulphur Trioxide

Abstract

The reaction of O atoms with SO3 yields SO2 and O2 as stable products, with a white metastable solid that condenses at –10°C (thought to be SO4) as a probable intermediate. The overall rate constants are 5 × 10–17, 7 × 10–17 and 9 × 10–17 cm3 molecule–1 s–1 at 300, 413 and 500 K, respectively. The activation energy is about 1 kcal mol–1, with a correspondingly low frequency factor of 3 × 10–15 cm3 molecule–1 s–1.

The reaction of N atoms with SO3 yields SO2 as a main product, with an overall rate constant of about 5 × 10–16 cm3 molecule–1 s–1 at 300 K.