Analysis of thermoelastic properties and equation of state for cyclopentane,tetramethylsilane and 2,3-dimethylbutane

The thermoelastic properties and equation of state for liquids such as cyclopentane, tetramethylsilane and 2,3-dimethylbutane at high pressures and high temperatures have been analysed. The pressure dependences of thermal expansivity and isothermal compressibility have been determined for these liquids under pressure up to 100?MPa along different isotherms at selected temperatures in the range 208.0–298.15?K. We have formulated the pseudospinodal model for different liquids, along different isotherms for evaluating both thermal expansivity and isothermal compressibility with the change in pressure. It is found that the spinodal pressure is a characteristic property of the liquid depending only on temperature. The results obtained in this study are in good agreement with the experimental data reported in the literature. The plots between thermal expansivity versus pressure along different isotherms intersect each other for tetramethylsilane and 2,3-dimethylbutane. However, in the case of cyclopentane the plots do not intersect each other.