Adsorption data for CH4, C2H6, C2H4, H-2, and N-2 on the zeolite 5A adsorbent (W. R. Grace & Davision Co.) were obtained at 293 K, 303 K, and 313 K. The pressure range studied was 0 to 2 MPa, which covers the operating pressure range in pressure swing adsorption (PSA) units. Experimental data were correlated by the Langmuir and Langmuir-Freundlich (L-F) equations for several isotherm models. This paper compares the Langmuir and L-F equations. Despite the relative simplicity of both isotherms, the experimental data were fit very well. In addition, the Clausius-Clapeyron equation was employed to calculate the isosteric enthalpy of adsorption.