  The repulsive term of Van der Waals equation of state has been deduced and
improved in this work using a probabilistic description of the configurational
entropy. The aim is to find out whether its physical basis is suitable for the
study of dense fluids like liquids and glasses. The extended Van der Waals
model accurately describes a system composed of independent Hard Spheres below
packing fraction {\eta} < 0.3, giving a pole at {\eta} ~ 0.51 in close
agreement with Molecular Dynamic simulation results. The inclusion of holes in
the configurational entropy description improves the model but only below
{\eta} < 0.2, precluding its application to high density fluids and glasses. In
addition, neither local nor global clustering of Hard Spheres can be described
using this approach. A physical model other than Van der Waals equation of
state is required to accurately describe the continuity of gaseous and liquid
states with the same expression. In this work, a model for the configurational
entropy of mixing is proposed which could reveal whether such continuity really
exists.
