The surface excess and the heat of immersion of the adsorption were investigated from benzene-ethanol mixtures onto activated carbon powder with the use of Gibbs adsorption equation and by measuring the calorimetric heat of immersion.
The equations for the surface excess and the heat of immersion were derived from the Gibbs adsorption equation, considering the surface areas occupied by each component of being different. The surface excess was estimated with the use of the UNIQUAC model for the bulk phase and the proposed model of its 2-dimensional image for the adsorbed phase.
Compared with Schay's results, the best prediction for the surface excess was obtainable using the UNIQUAC model for the bulk phase and the simplification of ideality for the adsorbed phase, considering the size effect of adsorbates.
The heats of immersion with compositions were measured with the solution calorimeter, and fairly reproduced from the equation derived.
