Question

Gaseous nitrogen has a density of 1.17 kg/m3 and liquid nitrogen has a density of 810 kg/m3.
[The relative molecular mass of nitrogen is 28.0]
What is the mean volume per nitrogen molecule in each case?
What is the mean separation between nitrogen molecules in each case?

Answer 1

1.17 kg/m^3 is
[1.17 kg/m^3*6.02*10^23 molecules/mole/28*10^-3 kg/mole]*
= 2.5*10^25 molecules/m^3

The mean separation is the -1/3 power or that, or about 3.4*10^-9 m.

The liquid separation distance is less by a factor (8.10/1.17)^1/3