A new method of of building isotherm curves for adsorption on silica and alumina gels, using the statistical polymer method, has been proposed. This method considers the chemisorption as the result of a chemical reaction between the adsorbent and the polymeric adsorbate, leading to the change of the weight distribution of multicomponent polymers, that is described directly by the equations of the multicomponent version of the statistical polymer method. The physisorption is considered as the formation of a weak complex between the adsorbent and the adsorbate inside micropores differing in the excess energy, that being described based on the micropores’ energy distribution found by the statistical polymer method. The estimated relative square dispersion is in most cases on the level of some percents. A widespread paradox-nonzero adsorption at P --> 0-is explained as the result not of chemisorption but of physisorption processes : more concretely, of the discrete form of the energetic distribution of micropores.