The importance of diffusion in catalyst pellets can often be determined by measuring the effect of pellet size on the observed reaction rate. In this exercise, consider an irreversible first-order reaction occurring in catalyst pellets where the surface concentration of reactant A is C_AS=0.15 M.

Data:

Diameter of sphere cm	0.2	0.06	0.02	0.01	0.008	0.006
robs (mol/h/cm3)	0.25	0.8	1.8	2.4	2.5	2.5

a.) Calculate internal effectiveness factor for each particle size

b.) Identify particles that experience no, negligible, intermediate, or strong diffusion limitation.

c.) Estimate the Thiele modulus for a catalyst particle of diameter 0.1 cm.