Abstract:
Methods are given of extrapolating the saturated vapor pressure of substances of “atmospheric range” to the entire liquid phase region from the triple to critical point. The extrapolation of the $pT$ parameters from room temperature to the triple point is performed by simultaneous processing of vapor pressure and of differences between the heat capacities of ideal gas and liquid. The liquid-vapor equilibrium in the region from the normal boiling temperature to the critical point is predicted by the law of corresponding states of L. P. Filippov using the experimentally obtained $pT$ data and values of density of liquids. Experimental facilities are described for determining the saturated vapor pressure by the comparison ebulliometric method and for determining the low-temperature heat capacity by the vacuum adiabatic calorimetry. The methods of extrapolating the vapor pressure are tested with standard substances for which reliable $pT$ data are available for the entire liquid phase region.