Isothermal Compressibility of Liquids at Low Pressures

Abstract

A simple borosilicate glass compressibility cell was constructed which allowed the measurement of relative volumes of liquids to a precision of ± 0.00002. The relative volumes of water, acetone, n-hexane and neopentane were measured at 25°C at pressures to 70 atm. In addition the relative volumes of n-hexane were measured at 50°C. Isobaric thermal expansion coefficients were measured for acetone and n-hexane in a narrow temperature range near 25°C. The isothermal relative volume data were fitted to theTait equation from which the isothermal compressibilities of the four liquids were computed. The compressibilities were slightly different from the compressibilities calculated from high pressure literature data fits of the Tait equation