Abstract: Specific surface area of solid is an important physico-chemical parameter. This kind of information is frequently required in describing the interactions between liquid and solid or gas and solid. In this paper, two equations which can be used to calculate the surface area of solid powder directly from the adsorptions enthalpy of liquid on solid are derived from the liquid solid surface state equations. Surface areas of eight metallic oxides have been calculated from the adsorption enthalpies measured by means of LKB-2107 Microadsorption Flow Calorimeter. For comparision, these surface areas have also been measured by using traditonal BET (N_2 adsorption) method. The results obtained by using these two methods agree quite well.

Key words: Solid powder, Surface area, Calorimetry, Adsorption enthalpy