The mean free path of nitrogen molecules at a pressure of 1.0 atm and temperature 0oC is 0.8 x 10^-7 m. If the number of density of molecules is 2.7 x 1025 /m³, then the molecular diamter is : 

3.2 \(A^o\)

Mean free path : \(\lambda\) = 0.8 x 10^-7 m

Number of molecules per unit volume : n = 2.7 x 10²⁵ /m³

Substituting these value in \(\lambda = \frac{1}{\sqrt{2} \pi n d^2}\)

We get : d = \(\sqrt{1.04*10^{-19}}\) = 3.2 x 10^-10 m 

d = 3.2 \(A^o\)