A Reduced Equation of State for Gases and Liquids

An empirical, reduced equation of state is presented which holds with reasonable accuracy for both liquids and gases. Liquid densities of non‐associated substances are predicted to within 4 percent, vapor pressures to within 25 percent, heats of vaporization to within 10 percent and gas isotherms reproduced to within 10 percent. The values predicted for the coefficients of thermal expansion and compressibility are not better than 30 percent. With the exception of the latter which are incapable of good representation by any such reduced equation, the equation represents a marked improvement over the van der Waals and Berthelot equations.