Consider the case in which liquid A evaporates and diffuses through stagnant gas B as

shown in Figure $1.$ Assuming that the process is carried out isothermically at $25C$

and the total pressure is $1$ atm, calculate the molar flux and the convective mass

transfer coefficient when the level of liquid $A$ is $0\mathrm{.}05m$ below the top of the container.

Assume that $D_{AB}=1\mathrm{.}0{10}^{-5}\frac{m^2}{s}.$ The mole fraction of $A$ at the gas$-$liquid interface

is $0\mathrm{.}2.$ At the top of the container, the mole fraction is $0\mathrm{.}001.[$Ans: $1\mathrm{.}82{10}^{-4}$kmo$\frac{l}{m^2}s$;

$9\mathrm{.}13{10}^4$kmo$\frac{l}{m^2}*s*atm|$