Air at $65\mathrm{.}6C,101\mathrm{.}3$kPa, flows at a velocity of $0\mathrm{.}8\frac{m}{s}$ through a packed bed of naphthalene spheres having a diameter of $6\mathrm{.}7mm.$ The total surface area of the spheres in the bed is $0\mathrm{.}015m^2$ and the void fraction is $0\mathrm{.}44.$ The tower diameter is $0\mathrm{.}067m.$ The vapor pressure of naphthalene is $340\mathrm{.}76Pa.$ Calculate the mass transfer coefficient and predict the outlet concentration of naphthalene in the exit air.

$[20\%]$

Given: $D_{AB}$ of naphthalene in air at $318K$ is $6\mathrm{.}92{10}^{-6}\frac{m^2}{s}.$