Such calculations prove
for all substances can be explained by Waals equation of state. universally it
can apply for substances found at gas phase being compressed into liquid.
Furthermore, research reports that applying equation (Critical point equation –
number them) related to critical point provides the critical gas compressibility factor, Zc, 0.375. It is
found in recent studies that substances share similar values to the
compressibility factors: 0.23-to-0.31. This
is acknowledged as the theorem of corresponding states.