Find the mean free path of gas molecules under standard conditions if the Van der Waals constant of this gas is equal to `b = 40 ml//mol`.

Explanation

We know that the Vander Waal's constant `b` is four times the molecular volume. Thus
`b= 4 N_A(pi)/(6) d^3` or `d = ((3 b)/(2 pi N_A))^(1//3)`
Hence `lamda = ((kT_0)/(sqrt(2) pi p_0))((2 pi N_A)/(3 b))^(2//3)`.