Diffusion of multiple gases at once Graham’s law of diffusion states the rate of diffusion between two gases is inversely proportional to their molar masses. Now, this is helpful when we are focused on two gases. But that is rarely the case in a beaker or even the atmosphere.
So how do you measure the rates of diffusion of many gases moving at once? Do you measure each rate of effusion (inversely proportional to molar mass) and just order them, then use stoichiometry to determine which one will be dispersed quickest based on the amounts present?
If the gases in a mixture are ideal then their diffusion is independent*.
The relationship described by Graham's law is transitive, therefore the relative effusion rate of multiple substances with respect to a reference substance also provides a ranking of their relative diffusion coefficients (an ordered list).
*Outside of condensed or supercritical phases it seems unlikely that two fluid substances would display sufficiently strong interactions to alter the relative order of their diffusion coefficients.