V.—Thermodynamics of Adsorption

Abstract

SUMMARY1. The adsorption of a gas has been investigated thermodynamically with special reference to the heat effects accompanying adsorption.2. Expressions are developed for three isothermal heats of adsorption of a gas and for the heat of immersion of a powder in a liquid.3. The effect of the variation of the surface of an adsorbent when adsorbing is examined, and it is shown from Titoff's observations (assuming, of course, the adsorption to be reversible) that the divergence between calculated and observed values of the heat of adsorption can be explained on the assumption of a change of surface area. The fractional change of surface per c.cm. adsorbed can be calculated, and also the surface energy per grm. adsorbent in vacuo.