In recent years, there has been rapid development in new methods for calculating the physicochemical properties of substances based on scaling principles (SP) and quantitative structure property relationships (QSPR). This paper presents an extended SP-QSPR model that can be used to predict the refractive index, surface tension, density, and viscosity of liquids on the saturation line. The temperature dependence of the molar refractivity is also considered. In this paper, we propose a new additive increment scheme for alkalies and its halogenated derivatives which can be used for calculations of orthochor, scaling values of parachor, molar refractivity, critical molar volume and the molar volume of a liquid subcooled to the absolute zero (T = 0 K). The correlation between structural-additive properties and critical molar volume is also discussed.