Kinetics of combination of oxygen atoms with oxygen molecules

Abstract

The kinetics of the reaction O + O₂+ M → O₃+ M (1) where M = O₂, He, Ar, or CO₂ have been determined at total pressures from 1 to 8 torr, the oxygen atoms being generated by pyrolysis of ozone at 1300°K. The rate constants observed in the temperature range 213–386°K when M = Ar and M = CO₂ can be represented by k^Ar₁=(1.7 ± 0.2)× 10¹³ exp (+1680 ± 100)/RT, and [graphic omitted] or alternatively by k^Ar₁=(2.85 ± 0.3)× 10¹⁴(T/298)^{–3.0 ± 0.2}, and [graphic omitted]. At 298°K the relative third-body efficiencies for equal molecular concentrations are O₂: He : Ar : CO₂=1.0 : 0.74 : 0.90 : 3.1.

The values obtained for k^Ar₁ are greater than those calculated from previous investigations of the kinetics of pyrolysis of ozone, even allowing for the accepted error in the equilibrium constant for reaction (1). Likewise the relative third-body efficiencies, with the exception of O₂ : He, differ from those derived from earlier work on the pyrolysis and photolysis of ozone.