Pattern of adsorption isotherms in Ono-Kondo coordinates

► Ono-Kondo (OK) theory is used to study intermolecular interactions in adsorbed phase. ► General pattern of isotherms in OK coordinates is determined and analyzed. ► The slope of OK graphs varies from positive at low pressure to negative at high pressure. ► The linear sections of OK graphs indicate the limits of the classical model. ► In the limit of high pressures, adsorbate is compressed at any value of Henry's constant.