Diffusion and Heterogeneous Reaction. X. Diffusion Coefficient Measurements of Atomic Oxygen through Various Gases

Steady‐state and time‐transient measurements of the decay of oxygen atoms in a cylinder with catalytic walls have been used to determine the diffusion coefficient of atomic oxygen in O₂, He, Ar, and Kr. The relative change in atom density as a function of distance (under steady‐state conditions) and time (after the atom source is shut off) was followed by observing the luminescence associated with the reaction of oxygen atoms with nitric oxide. The diffusion coefficients at 298°K and 1 atm were found to be: $D_o{-}_{\text{o2}}{\text{\hspace{0.17em}=\hspace{0.17em}0.27; D}}_o{-}_{\mathrm{He}}{\text{\hspace{0.17em}=\hspace{0.17em}0.73; D}}_o{-}_{\mathrm{Ar}}{\text{\hspace{0.17em}=\hspace{0.17em}0.39; D}}_o{-}_{\mathrm{Kr}}\text{\hspace{0.17em}=\hspace{0.17em}0.16}{\mathrm{cm}}^2{\sec }^{\text{−1}}.$