CO$2$ is being absorbed in a strongly alkaline solution from a gas mixture containing $12\%$ CO$2,$

$22\%$ N$2$ and $66\%$ H$2.$ Nitrogen and Hydrogen are virtually insoluble. Calculate the rate of

absorption in kmol$/$m$2.$sec through a gas$-$film of $1\mathrm{.}5$ mm thickness if the ratio of volume

fractions of N$2$ and H$2$ remains constant over the diffusion path. The temperature if $50$oC

and the total pressure is $5$ bar. Assume that CO$2$ reaching the solution is absorbed

instantaneously.

Given data of experimental diffusivity values: DCO$2-$N$2=2\mathrm{.}12\backslash$times $10-5$ m$2/$sec $[$at $296$ K and $1\mathrm{.}013$

bar$]$; DCO$2-$H$2=6\mathrm{.}46\backslash$times $10-5$ m$2/$sec $[$at $298$ K and $1\mathrm{.}013$ bar$]$; DH$2-$N$2=7\mathrm{.}73\backslash$times $10-5$ m$2/$sec $[$at $297$ K

and $1\mathrm{.}013$ bar$].$