Benzene, a contaminant in groundwater, is diffusing into an inert porous mineral particle at 25°C. The particle has a void fraction of 0.40 with a mean pore diameter of 0.30 mm, and the pores are filled with groundwater. The molecular weight of benzene (solute A) is 78 g/gmole, and the critical volume (Vc) is 259 cm³/gmole. The mass concentration of benzene in the groundwater surrounding the particle is 0.100 g/L, which is below its solubility limit.

a. What is the molar concentration of benzene in the groundwater?

b. What are the mole and mass fractions of benzene in the groundwater?

c. Estimate the molecular diffusion coefficient of benzene in groundwater.

d. Justify why hindered diffusion of the benzene solute through the solvent-filled pore can be ignored.

e. Estimate the effective diffusion coefficient of benzene within the water-filled porous mineral particle.