A dialysis machine will be designed to remove urea from the blood of a kidney patient. The concentration of urea in the blood is initially 21 mg/100 cc and after undergoing dialysis it should be 2 mg/100 cc. The membrane thickness is 1.59 X 10-5 m, K = 0.75, DAB = 3.5 x 10-11 m2/s inside the membrane, the mass transfer coefficient in the blood is 1.25 X 10-5 m/s and 3.33 x 10-5 m/s in the dialysate. Calculate the total area of the membrane in m2 of the dialysis machine if its to remove 9 g urea /h.