Question

QUESTION 2 [20 MARKS] Ammonia (A) - water (B) solution is in contact at a surface with an organic liquid at 278 K. The concentration of ammonia in the organic phase is 10 wt%, and the density of aqueous solution is 961.7 kg/m². Meanwhile, the concentration of ammonia in water at the other end of the film at 5.4 mm away is 2.5 wt%, and the density is 991.7 kg/m². The flux of ammonia and the water is considered as equimolar counter diffusion. Given the flux of ammonia, Nis 1.2 x 105 kg mol/s.m? and the average atomic weight of ammonia and water are 17 and 18 kg/kgmol, respectively. a) Calculate the diffusivity, DAB of ammonia in water (m/s) at 278 K. (14 Marks) b) Based on the value of DAB obtained in (a), estimate the new Da value of ammonia in water if the temperature is increased by 5% from the actual temperature operation condition. (6 Marks)

Mass transfer questions.