Densities of tetramethylsilane, tetraethylsilane, and tetraethoxysilane under high pressures

Abstract

Accurate density data for tetramethylsilane, tetraethylsilane, and tetraethoxysilane in the temperature range from 283.15 to 333.15 K under pressure up to 100 MPa have been measured in order to test existing correlation methods. We have also measured the saturated liquid densities of tetramethylsilane, tetraethylsilane, and tetraethoxysilane in the temperature range from 283 to 343 K. The modified Rackett equation and the COSTAD correlation were used to correlate the saturated liquid density data. The Tait equation and a modified van der Waals equation of state were used to correlate the liquid density data under pressure. It was found that the average absolute deviations of the experimental values from those calculated with the Tait equation and the modified van der Waals equation of state were less than 0.01 and 0.21%, respectively. The effective hard sphere diameters for these three silane compounds were determined from the modified van der Waals equation of state parameter. It was found that the effective hard-sphere diameter decreases with temperature.