x/m = $\frac{aP}{1 + bP}$. Or: theta = $\frac{KP}{1 + KP}$ 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: $\frac{P}{x/m}$ = 1/a + $\frac{b}{a}$P. Plot $\frac{P}{x/m}$ vs P: straight line. More realistic than Freundlich at high pressures.