Compare the effective diffusion coefficient for a dilute mixture of oxygen gas (O₂, species A) in nitrogen gas (N₂, species B) at 20°C and 1.0 atm within the following materials:

a. Straight 10 nm pores in parallel array

b. Random pores of 10 nm diameter with void fraction of 0.40

c. Random pores of 1.0 mm diameter with void fraction of 0.40

From Appendix J, Table J.1, the molecular diffusion coefficient of O₂ in N₂ gas is 0.181cm²/s at 1.0 atm and 273 K. Remember, 1 × 10⁹ nm = 1.0 m, and 1 × 10⁶ μm = 1.0 m.