The volume-average adsorbate loading of a spherical particle is given by (15-49). Show that a parabolic adsorbate loading profile proposed by Liaw, C.H. et al. [AIChE J., 25, 376–381 (1979)], q = a₀ + a₁r + a₂ r², may be used to obtain a transport-rate resistance term for intraparticle diffusion for a thermodynamic driving force given by the difference between the solute concentration on the particle at its outer surface (r = R_p) and the volume-average adsorbate loading, by equating the rate of accumulation of adsorbate within the particle to Fick’s first law for diffusion into the particle evaluated at the particle outer surface.