The thermodynamic property surfaces for a singlecomponent adsorbent + adsorbate system have been derived and developed from the view point of classical thermodynamics. These thermodynamic frameworks enable us to compute the specific heat capacity, partial enthalpy and entropy for the analyses of adsorption processes thoroughly. A theoretical framework for the estimation of the isosteric heat of adsorption between an adsorbate (vapor) and an adsorbent (solid) is also derived for the thermodynamic requirements of chemical equilibrium, Maxwell relations and the entropy of the adsorbed phase. Conventionally, the specific heat capacity of the adsorbate is assumed to correspond to its liquid phase specific heat capacity and more recently to that of its gas phase. We have shown here that the derived specific heat capacity fills up the information gap with respect to the state of adsorbed phase to dispel the confusion as to what is the actual state of the adsorbed phase.