Estimate the surface area of the silica gel by using the adsorption data for oxygen at -183°C. The density of the liquefied oxygen at -183°C is 1.14 g/cm³. The data at -183°C is: V = 22,400 cm³/g mol; I = 0.40 x 10 cm³; s = 13.2 x 10-3 cm³.