Problem 1

An ammonia (A)-water (B) solution at 278 K and 4.0 mm thick is in contact at one surface with an organic liquid at this interface. The concentration of ammonia in the organic phase is held constant and is such that the equilibrium concentration of ammonia in the water at this surface is 2.0 wt % ammonia (density of aqueous solution 991.7 kg/m3) and the concentration of ammonia in water at the other end of the film 4.0 mm away is 10 wt % (density 961.7 kg/m3). Water and the organic are insoluble in each other. The diffusion coefficient of NH3 in water is 1.24 x 10-9 m2/s.

a.At steady state, calculate the flux NA in kmol/s m2.

b.Calculate the flux NB.