Collision Theory of the Kinetics of Dissociation of Diatomic Molecules

A collision theory is developed for the rate of dissociation of diatomic molecules dilutely dispersed in an inert gas, the theory being identical in its basic structure to the collision theory of Rice but differing from the latter in some of its details. The rate constant is found to be $${\mathrm{\kappa =c(\mu }}^{\frac{1}{2}}{A}^{\frac{1}{2}}{\mathrm{/\hslash r}}_0^2\mathrm{)Z}\exp \mathrm{(-D/kT),}$$ where Z is the collision number, D the dissociation energy, μ the reduced mass of the diatomic molecule, r₀ its equilibrium internuclear distance, A the magnitude of the coefficient of the attractive r^—6 term in the long‐range interaction energy of its two atoms of its diatomic molecule, and c a dimensionless constant estimated to be 0.27.