A consideration of the correct calculation of thermodynamic parameters of adsorption

The Langmuir and Freundlich isotherm equations have been widely used for interpreting various adsorption processes. There are, however, many serious mistakes in the literature in determination or calculation of thermodynamic parameters, especially in the determination of the change in the free energy of adsorption using Langmuir, Freundlich and Henry constants. Many authors used these constants for the determination of ?G expressed instead of dimensionless in some concentration units (for example: l mol-1, l g-1, ml mg-1, etc.).