1. Calculate the value of mass transfer rate from a naphthalene sphere (with 20 mm diameter) to air at 20 C and 1 atm, a) if air is stagnant b) if air is flowing at a velocity of 2 m/s c) Compare the results for this situations and explain what causes this difference. Data: at T=20 C and PT=1 atm, Density of air, air=1.2 kg/m3 Viscosity of air, =1.8x10-5 Partial pressure of naphthalene, Ponaph=0.5 mmHg Diffusivity of naphthalene in air, Dnaph-air=4.5x10-6 m2/s