Calculate the ratio of the mean free paths of the molecules of two gases having molecular diameters 1 Ao and 2 Ao. The gases may be considered under identical conditions of temperature, pressure and volume.

Mean free path of a molecule is given by   l=12d2nwhere n = number of molecules/volume           d = diameter of the moleculeNow, we can write l∝1d2 Given, d1=1Å,d2=2A As  l1∝1d12 and l2∝1d22⇒ So, l1l2=d2d12=212=41 Hence, l1:l2=4:1