The calculated results from the adsorption data for alcs., ketones, and esters on the silica gel and for aromatic compounds on active carbon from cyclohexane show that each functional group can be assumed to make its own contribution to the Henry coefficient K (K = nmsb), i.e., ln K = ln (nmsb) = Sniln (nmsb)i, where nms is the limiting adsorption, b is the adsorption coefficient, ni is the no. of functional group in a mol., and (nmsb)i is Henry coefficient of functional group i. The additive scheme can be used for determination of adsorption isotherms under the same conditions on the basis of the contributions to the Henry coefficient by individual functional groups and of the no. of groups in the mol.

Key words: ADSORPTION, ADSORBENT, CARBOXYLIC ACID ESTER, ALCOHOL, KETONE, CYCLOHEXANE, SILICA GEL, ACTIVATED CARBON