Q19 of 31 Page 94

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

Mean free path of a molecule is defined as the total distance travelled by molecule between successive collisions.


The mean free path (λ) of a molecule is given by


…(i)


Where,


n= no. of molecules per unit volume


d= diameter of molecule


Given:


Diameters of two gas molecules have diameters and


From eqn.(i) we have




Therefore, ratio of mean free path of two molecules is 4:1.


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