A general equation of state for dense liquid alkali metals

Abstract

A general equation of state proposed by Parsafar and coworkers for compressed fluids is developed to compressed liquid alkali metals. According to the resulting equation of state p/ ρ 2 is a linear function of ρ, where p is the pressure and ρ is the molar density. The slope and intercept of the linear equation are linearly temperature-dependent, i.e., by adjusting four temperature-independent parameters one can predict the volumetric behavior of dense molten alkali metals. The equation of state has been employed to calculate the liquid density of compressed alkali metals over a wide range of temperatures, from melting point up to 2000 K, and pressures ranging from saturated vapor pressure to 1000 bar. The agreement of the predicted results with experiment is remarkable. Also the equation of state has been used to calculate densities, isobaric expansivities, and isothermal compressibilities of liquid alkali metals in the saturation state. The linearity of bulk modulus versus pressure, common bulk modulus point, common compression factor point, linear isotherm regularity, and the linearity of inverse isobaric expansivity versus pressure for compressed liquid alkali metals has been checked by utilizing the present equation of state.