a) Solute A is transferred from V to L phase in a packed tower. The partial pressure of A in the V phase is Pa and the molar concentration of A in the L phase is CA. Write the local flux of Aif Ka is known. b) Consider the tray drying of a food material at constant temperature and humidity. The thickness of the material in the tray is x. Drying takes place from the top, and the mass transfer coefficient, kyMo is proportional to the mass flux of air as 0.0137G47. Calculate the change in drying rate if the velocity of air is doubled in the constant rate and diffusion controlled falling rate drying period. c) An extruded product of small spheres is to be dried in a through-circulation drier (air flows through a bed of solids). The particles are to be arranged in beds of x mm deep on screens with a void fraction . The air flow rate (velocity v) is adjusted so that the Reynolds number is 920 and the Schmidt number is 0.65. Show how to estimate the mass transfer coefficient, kyM (kg/m.s.AH)