$5\mathrm{.}4.$ A wet$-$walled column with a diameter of $40mm$ and a length of $1m$ is used for the experimental determination of the liquid phase average mass transfer coefficient $k_x$ for the $S{O}_2-$ air$-$water system at $1$ atm and $30C.$ The speed of the gas entering the column is $0\mathrm{.}2\frac{m}{s}$ and the concentration of $S{O}_2$ in it is $2\%.$ The concentration of $S{O}_2$ in the released gas is $0\mathrm{.}2\%.$ The entering water is pure water. The concentration of $S{O}_2$ in the exiting water is XAL$=0\mathrm{.}00012.$ Under experimental conditions, the interfacial concentration on the liquid phase side can be taken as constant throughout the column and xa$=0\mathrm{.}00018.$ Calculate the liquid phase mass transfer coefficient in$\{\begin{array}{c}\frac{\text{k}\text{m}\text{o}\text{l}}{m^{2}s.x}\end{array}$