Consider the cracking of cumene C9H12 in the presence of silica-alumina catalyst particles at 1atm and 510C. Use the following data to calculate the effective diffusivity, and determine the dominant mode of diffusion: Particle diameter =0.43cm, Specific surface area =342m2/g, Particle density =1.14g/cm3, Porosity = 0.51 , Tortuosity factor =3, Molecular diffusivity =0.15cm2/s