A flat steel plate that is 3.0 m in length and 3.0 m in width and it initially contains a thin coating of lubricating oil. Air at 386 K and 1.0 atm is blown parallel to the surface at a velocity of 50 m/s. At 386 K the viscosity of air is 2.23 x 10-⁵ kg/m.s, and the lubricating oil is slightly volatile with a vapor pressure of 0.2 Pa, and the liquid density of the lubricating oil is 1900kg/m³. At 386 K and 1.0 atm, the molecular diffusion coefficient of the lubricating oil vapor in air is 0.040 cm²/s.
a. What is the Schmidt number for the mass transfer of lubricating oil vapor in air?