STUDIES ON THE ADSORPTION FROM NON-AQUEOUS SOLVENTS. PART III

Adsorption of two more solutes—cinnamic add (polar) and phenanthrene (non-polar), in both polar and non-polar solvents has been studied. The changes in the amounts adsorbed from different solvents have been explained on the basis of differences in the internal pressures of solute and solvent. It has been observed that since in a solution consisting of two components, where exists a difference in the internal pressure, the escaping tendencies change, and hence, adsorption also changes. The change increases with the difference and may be positive or negative. It is:positive when the solute has a lower internal pressure than the solvent, and negative, when higher. Deviations from the rule occur due to polarity. The adsorption of naphthalene, phenanthrene, benzoic acid and cinnamic acid increases with the increase in the difference, in the solvents having higher internal pressures. But the increase is less marked in acids due to their polarity. The adsorption of naphthalene and phenanthrene decreases with the increase in the difference, in the solvents having a lower internal pressure, but of acids under the same conditions increases, which has been explained due to their polarity.