Diffusion with chemical reaction: A gas is absorbed by a solution with which it reacts chemically. The rate of diffusion in the liquid can be assumed proportional to the concentration gradient, and the diffusing gas is eliminated as it diffuses by a first$-$order chemical reaction. The reaction rate is proportional to the concentration of the solute gas in the liquid. Obtain an expression for the concentration in the liquid as a function of the distance from the gas$-$liquid interface $.$ Hint A $1-$D mass balance with chemical reaction is obtained using a $1-D$ shell balance as follows: $A[J_x{]}_x-A[J_x{]}_x+dx=$kCAd, where $kC$ is rate of reaction.