VAN DER WAALS EQUATION

A semiempirical equation that describes the relationship between pressure (P), volume (V), temperature (T), and moles of gas (n) for a real gas. The equation is (P + n 2 a/V 2 )(V - nb) = nRT, where a and b are constants that include the effects of molecular attractions and molecular volume. a and b are usually fitted to experimental data for a particular gas.