@wikipedia

Volume occupied by one mole of a substance (chemical element or chemical compound) at a given pressure  and temperature :

V_m(p, T) = \frac{V}{\nu} =\frac{M}{\rho}= \frac{1}{\rho_m} = \frac{N_A}{n}

where

Molar volume  is directly related to the average intermolecular distance  and in case of isotropic substance: .

Molar volume  is inverse to Molar Density : 

V_m = \frac{1}{\rho_m}

In case of fluid which satisfies Real Gas EOS @model the Molar volume  can be expressed in terms of Z-factor :

V_m = \frac{ZRT}{p}

where

Molar volume of the mixture is:

V_m(p, T) =\frac{M}{\rho_f} = \frac{\sum_k M_k \cdot x_k}{\rho_f}