Pressure dependence of the diffusion coefficient
Diffusivity or diffusion coefficient is a proportionality constant between the molar flux due to molecular diffusion and the gradient in the concentration of the species (or the driving force for diffusion).
For self-diffusion in gases at two different pressures (but the same temperature), a empirical equation has been suggested.Related formulas
|diffusion coefficient at pressure 1 (dimensionless)
|diffusion coefficient at pressure 2 (dimensionless)
|gas mass density at pressure 2 (dimensionless)
|gas mass density at pressure 1 (dimensionless)