liquid B Z=0 3. Consider a liquid "B" flowing inside a rectangular duct under laminar flow conditions, as shown below. The wall located at y = O is pure A and it is soluble in B. As A diffuses into the liquid, it is consumed by a homogeneous first-order reaction. Using a shell mass balance or the appropriate species continuity equation, find the governing differential equation that describes the concentration of A (CA) in the duct, and the appropriate boundary conditions. State any assumptions you make, do not attempt to solve. The wall located at y = b is impermeable to species A. soluble wall of A ZEL y = 0 y = b