Q1- Estimate the value of the mass transfer coefficient in a stream of air at 325.6 K flowing in a duct by the following shapes made of solid naphthalene. The velocity of the air is 1.524 m/s at 325.6 K and 202.6 kPa. The DAB of naphthalene in air is 5.16 x 106 m2/s at 273 K and 101.3 kPa. 1. For air flowing parallel to the flat plate 0.152 m in length. 2. For air flowing by a single sphere 12.7 mm in diameter. Q2- In a wetted-wall tower an air- H2S mixture is flowing by a film of water which is flowing as a thin film down a vertical tube. The H2S is being absorbed from the air to the water at a total pressure of 1.5 atm abs and 30 °C. The value of k', of 9.567 x 10 m/s has been predicted for the-gas phase-mass transfer coefficient. At a given point the mole fraction of H2S in the liquid at the liquid gas interface is 2 x 105 and PA (atm) = 609 x (mole fraction liquid). Calculate the rate of absorption of H2S. [Hint: Call point 1 the interface and point 2 the gas phase. Then calculate par from Henry's law and the given x4. The value of P42 is 0.05 atm]. Q3- Mass transfer from a sphere of naphthalene that has a diameter of 0.1 ft to air at 113 °F and 1 atm abs. flowing at a velocity of 3600 ft/hr. the diffusion coefficient of naphthalene in air at 113 °F and 1 atm abs. is 0.2682 ft²/h. The vapor pressure of solid naphthalene at 113 °F is 0.555 mm Hg. The viscosity and the density of air at 113 °F are 0.0467 (lb/ft.h), 0.0695 lb/ft³ respectively. The gas constant is equal to 0.73 (ft³.atm/lb.mol °R). The mass transfer correlation for flow past a sphere is as follows: Nsh =2+0.552 (NRe)0.52 (NSC)/3 Find: a) Mass transfer coefficient kc b) Nst c) JD D) If the above correlation is applied, predict Kc and find the flux and rate of naphthalene from the sphere. e) If the gas is not moving determine Nsh and Kc. By which mode mass transfer occure. f) Determine the thickness of the boundary layer