1.Ab. Concentration of a flue gas A flue gas consists of carbon dioxide, oxygen, water vapor, and nitrogen. The molar fractions of CO2 and O2 in a sample of the gas are 12% and 6%, respectively. The welght fraction of H2O in the gas is 6.17%. Estimate the density of this gas at 500K and 110kPa. 1.81. Membrane area required for dialysis One of the oldest membrane materials used for dialysis is porous cellophane, a thin transparent aheet made of regenerated cellulose. Typical values of parameters for commercial cellophane membranes are as follows; thickness =80m, porosity =0.45, tortuosity =5.0, and pore diameter =40A (Seader and Henley, 2006). (a) Estimate the effective diffusivity of urea through this membrane at 298K. The diffusivity of urea in dilute aqueous solution at this temperature is 1.38105 cm2/s. The molecular diameter of urea is 5.28A. (b) The artificial kidney of Example 1.3 uses a cellophane membrane. If the urea concentration difference across the membrane is 25mg/dL, estimate the memrane area required. Answer: 6.3m2