Mass Transfer

7) Mass transfer is occurring from a sphere of naphthalene having a radius of 5mm. The sphere is in a larger volume of still air at 350 K and 1atm abs pressure. The vapor pressure of naphthalene at 350K is 3.0mmHg. Consider its diffusivity at 293K is 7106 m2/s. Calculate the rate of evaporation of naphthalene from the surface. 8) Please calculate the diffusivity of ethanol vapor and methane using Fuller et al. method, under atmospheric pressure at 350K and 500 K. Which diffusivity value is larger? Please explain