Prediction of thermal pressure coefficient by the law of corresponding state and group contribution

An improved correlation to estimate the thermal pressure coefficients of liquids over a wide temperature range from the triple point to the critical point is presented: γ = (0.569Rb∗) exp(b∗V), where b∗ is a substance-dependent constant whose value can be evaluated from one reliable experimental γ value of from group contribution. The calculation shows that the precision of both methods is far higher than that of the hard-sphere method.