Answer ALL parts (a) - (d). [Parts (c)-(d), absorption-column design, are omitted.]

The equilibrium distribution of a solute A between gas and water at a particular temperature is given as $y_A = 1.2x_A$, where $x_A$ and $y_A$ stand for mole fractions of solute A in the liquid and in the gas phases, respectively. At a certain point in a mass transfer device, the concentration of solute A in the bulk air is 0.04 mole fraction and that in the bulk aqueous phase is 0.025. At the same point, the local individual mass transfer coefficients in the gas and liquid phases are $k_y = 7.2\ \mathrm{kmol\,h^{-1}\,m^{-2}}(\Delta y)^{-1}$ and $k_x = 4.6\ \mathrm{kmol\,h^{-1}\,m^{-2}}(\Delta x)^{-1}$.