Scaling-Law Equation of State for Gases in the Critical Region

The Widom-Kadanoff scaling-law equation of state has been confirmed for a variety of gases in a range of ±{}50% of the critical density and within a few percent above and below the critical temperature. Using a new procedure motivated by the scaling law, the exponent δ describing the shape of the critical isotherm was found to be close to 5 while the compressibility exponents γ and γ^' were both found to be equal to about 1.4.