AbstractExperimental kinetic uptake curves for two sorbates (cis‐2‐butene from the gas phase and n‐heptane from the liquid phase) have been measured in a variety of 5A molecular sieve pellets. Conditions were selected to fulfil either the linear isotherm approximation of the Ruckenstein(3)model or the rectangular isotherm approximation of the preceding paper. For these systems both macropore and micropore diffusional resistances are significant and it is shown that the theoretical models provide a satisfactory interpretation of the experimental uptake curves. Time constants for both macropore and micropore diffusion, calculated by matching experimental and theoretical uptake curves, are consistent with independently measured v