It is desired to recover hexane vapor (solute A) from air using an absorption process. The absorption solvent is a nonvolatile mineral oil, which has a mass density of 0.80 g/cm³and a molecular weight of 180 g/gmole. In the dilute concentration range, the equilibrium relationship for the dissolution of hexane vapor in the mineral oil at 20°C is described by p_A,i= H x_A,i, where H = 0.15 atm. At the present conditions of operation, the hexane partial pressure in the bulk gas stream is 0.0 15 atm, and the dissolved hexane in the bulk absorption solvent is 5.0 mole%. The total system pressure is 1.50 atm, and the temperature is 20°C. The liquid film mass-transfer coefficient k_xis 0.01 kgmole/m²· s, and the gas film mass-transfer coefficient is k_y0.02 kgmole/m²· s. 

a. What is the overall mass-transfer coefficient based on the liquid phase, K_L, and molar flux N_A? 

b. What is the composition of hexane at the gas€”liquid inter face, in terms of p_A,i and x_A,i?

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1003 ст3 Рв — 0.8 ст3 — 8 х 105. т3 т3 Мв = 180 mole' T = 293 K, P = 1.5 atm 0.015 atm 0.015 atm, PA = 0.01, УА — XA = 0.05 1.5 atm kgтole ky : — 0.02 Кдтоle т2.s kx 0.01 т?.s НХАi» 0.15 atm PA,i = Н