21.2-1. Dimensional Analysis in Mass Transfer. A fluid is flowing in a vertical pipe and mass transfer is occurring from the pipe wall to the fluid. Relate the convective mass-transfer coefficient $k_c$ to the variables $D$, $\rho$, $\mu$, $v$, $D_{AB}$, $g$, and $\Delta \rho$, where $D$ is pipe diameter, $L$ is pipe length, and $\Delta \rho$ is the density difference.\nAns. $\frac{k_c D}{D_{AB}} = f \left( \frac{gL^2 \rho \Delta \rho}{\mu^2}, \frac{D \mu}{\rho D_{AB}} \right)$
