Like b0, the temperature independent factor of the velocity coefficient, fco, can be calculated theoretically. For a kinetic estimate, we assume that fc0 equals the number of adsorption places multiplied by the probability that an adsorbed molecule reacts when in possession of the activation energy. This probability, according to usual assumptions, is a vibration frequency v of the order of 1013 sec-1. Thus, we arrive at [Pg.258]

The D/R adsorption isotherm has a theoretical basis which is outside the scope of this book. Its use requires three types of information (1) a calculation of the thermodynamic amount of non-mechanical (i.e., chemical) work associated with a quantum of adsorption, without regard to the specific solvent or the specific adsorbent involved, but with regard to the relative volume of solvent available for adsorption (2) independently determined empirical constants — known as affinity constants, noted by the symbol P — which allow extrapolation from one solvent to another and (3) a characteristic energy of adsorption — noted by the symbol AEq — which is primarily based on the characteristic dimensions of the micropores. [Pg.334]

© 2019 chempedia.info