$($a$)($i$)$ What is on impermeable surface in mou trander $($ii$)$ How is is express and mass bavis mathematicalty, and $()$ vhat is the counterpat of the impermectie surface in heat transter? $($b$)$ Dry ofr af $40C$ and $0\mathrm{.}85$ pitm flowns over on $8$ m long wet flot surface with an average velocity of $2\mathrm{.}5\frac{m}{s}$ in acider to dry the surface. Determine the mass transfer coefficient on the plate. Tloke the properties of the diny at the specified temperafure to be; Kinemaric viscosity $=0\mathrm{.}03601702\frac{m^2}{s}.$ Dimp $=1\mathrm{.}3710\frac{871}{5}{c}^{\frac{1}{3}}.$