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.