x/m = aP/(1 + bP). Or: theta = KP/(1 + KP) where theta = fraction of surface covered. Assumptions: (1) Monolayer adsorption only. (2) All surface sites are equivalent. (3) No interaction between adsorbed molecules. (4) Dynamic equilibrium between adsorption and desorption. At low P: theta ≈ KP (linear, first order in P). At high P: theta ≈ 1 (surface fully covered, zero order in P). Linear form: P/(x/m) = 1/a + (b/a)P. Plot P/(x/m) vs P: straight line. More realistic than Freundlich at high pressures.