Flame photometric determinations of diffusion coefficients. Part 6.—Results for carbon monoxide and free atoms of bromine, iodine and thallium

Abstract

Diffusion coefficients are measured for trace amounts of CO and free atoms of Br, I and Tl in the burnt gases of eight pre-mixed laminar flames of H₂, O₂ and N₂, covering the temperature range 1900 to 2520 K at atmospheric pressure. The measured diffusion coefficients are interpreted in terms of both the Lennard-Jones (12 : 6) potential function and a totally repulsive inverse power function describing interactions between the diffusing and flame species. We conclude that the Lennard-Jones function fits the observations better than the purely repulsive one. Values of the Lennard-Jones parameters for each diffusing species are presented, together with the constants characterising repulsive forces.