A process waste gas stream containing 5.0 mole% of benzene (solute A) enters the bottom of a packed tower. The tower is packed with 0.5-inch ceramic Raschig rings, and the diameter of the tower is 2.0 ft. The inlet gas flow rate is 32.0 lbmole/h (1006 lb/hr). The waste gas exiting the tower contains 1.0 mole% of benzene, and its total molar flow rate is 30.7 lbmole/h. A nonvolatile scrubbing oil (molecular weight of 250 g/gmole), which contains no benzene, is added to the top of the tower at the rate of 18 lbmole/h to absorb solute A from the gas phase. At these conditions, the overall mass-transfer coefficient based on the gas phase, K_Gα, is 2.15 lbmole/ft³ · h · atm. The total system pressure is 1.40 atm, and the temperature is isothermal at 27°C, and the equilibrium distribution of solute A between the contacting gas and liquid phases is described by Henry’s law, where P_A = H x_A, where H = 0.14 atm, based on the definition p_A = H · x^*_A. Additional data: gas density, ρ_G = 0.11 lb_m/ft³; liquid density, ρ_L = 55 lb_m/ft³; liquid viscosity, µ_L = 2.0 cP. 

a. What is the mole fraction of solute A in the liquid exiting the tower? 

b. What is the packed height of the tower? 

c. At the conditions of operation, the gas-phase pressure drop in the tower is 300 Pa/m. If the packing is changed to 25- inch ceramic Raschig rings, what is the new pressure drop?