Van der Waals Equation
An equation of state modifying the ideal gas law to account for finite molecular volume and attractive intermolecular forces in real gases.
Governing formula
(P + a n² / V²) (V - n b) = n R T
SI unit
Pa·m³
In depth
Parameter $a$ accounts for attractive intermolecular forces (lowering wall pressure), while parameter $b$ accounts for excluded volume of hard-sphere gas molecules.
Examples in the real world
Accurately modeling real gas condensation behavior and critical point transitions near high pressures.