Temperature dependence of the rate constants for the third order reactions: O2++2O2=O4++O2 and O4++2O2=O6++O2

The temperature dependence of the rate constants for the reactions: ${\mathrm{O}}_2^{+}\text{+2}{\mathrm{O}}_2={\mathrm{O}}_4^{+}+{\mathrm{O}}_2\text{\hspace{0.17em}(1)}$ , ${\mathrm{O}}_4^{+}\text{+2}{\mathrm{O}}_2={\mathrm{O}}_6^{+}+{\mathrm{O}}_2\text{\hspace{0.17em}(2)}$ , were measured in a pulsed electron beam mass spectrometer in the temperature range 80–300 °K. The values k₁ = 2.6 × 10⁻³⁰ and k₂ = 7 × 10⁻³² cm⁶ molecule⁻² · sec⁻¹ were obtained for 300 °K. Both reactions were shown to be third order. The temperature dependence fitted the relationship k = const T⁻ⁿ; n = 3.2 for Reaction (1) and 5.1 for Reaction (2). The equilibrium constants K₁ and K₂ could be measured over most of the experimental range. Van't Hoff plots of the equilibrium constants led to an approximate confirmation of ΔH₁ and ΔH₂ determined earlier by Conway.