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(a) In briefly, explain the differences between molecular diffusion and convective mass transfer? (b) Calculate the flux of a steady state diffusion of CO2 gas in nitrogen at 266K and atmospheric pressure through 65cm bed depth of particles with a porosity of 35% and a tortuosity of 2.75 . The partial pressure of CO2 at the one side of the bed is 2.026103Pa and CO2.free gas at the other side. (c) Solute A is absorbed from an inert gas into liquid B in a 0.5m long wetted column. The initial concentration of A in the liquid is 2kgmol/m3 and the partial pressure of A in the gas is 0.015atm. The concentration of A in the gas and liquid at the interface are related by the expression: CA=150PA where the units are: PA in atm and CA in kgmol/m3. If the maximum velocity of the liquid is 3103m/s and DAB is 9108m2/s, determine: i. The concentration of A at a point of 0.01m from the gas-liquid interface. ii. The penetration distance of A in the liquid