The Freundlich Isotherm is a model that describes how solutes adsorb onto surfaces, particularly in heterogeneous systems. It is represented by the equation q_e = K_f C_e^1/n , where q_e is the amount of solute adsorbed per unit mass of adsorbent, C_e is the equilibrium concentration of the solute, and K_f and n are constants specific to the system. This isotherm is useful for understanding adsorption processes in various fields, including environmental science and chemical engineering. Unlike the Langmuir Isotherm, which assumes uniform adsorption sites, the Freundlich model accounts for varying affinities of different sites on the adsorbent surface.