An Accurate Vapor Pressure Equation with Good Extrapolation Characteristics

A new vapor pressure equation that has only three adjustable parameters and a simple form is preseInted in this paper. The equation is valid over the entire range from the triple point to the critical temperature for a chemically diverse set of compounds. It can represent the experimental data with an accuracy comparable to the Wagner vapor pressure equation. The advantage of the new equation is that it can be used to extrapolate well from a small amount of data in the usual range to the entire vapor–liquid coexistence region both up to the critical temperature and down to the triple point. Satisfactory results are preseInted for more than 40 substances in tables, and it has been shown that the new vapor pressure equation is generally valid in a wide range.