Question

which model is better to use to adequately describe the adsorption system of oxalic acid onto charcoal Langmuir or freund

Answer 1

Langmuir's model was a theoretical construct, while the Freundlich isotherm is empirical. In the Langmuir model, it is assumed that at maximum coverage, there is only a monomolecular layer on the surface. This means that there is no stacking of adsorbed molecules. The Freundlich isotherm does not have this restriction.

As from the figure, we can see that monolayer formation is quite understandable then Langmuir isotherm is better to use. Also, Freundlich isotherm is an empirical formula, so it is always better to use Langmuir isotherm as it is theoretically proved one.