2. The molar mass transfer rate from a 50mm diameter naphthalene sphere placed in stagnant air at 85.8C and atmospheric pressure is 1.5107kmol/s. If air starts flowing across the surface of naphthalene with a velocity of 3m/s, by what factor will the mass transfer rate increase, all other conditions remaining the same? At 85.8C vapor pressure of naphthalene is 13.3mbar, the viscosity and density of air are 2.1105kg/m.s and 0.974kg/m3. Assume that bulk concentration of naphthalene in air is negligible