A solid containing species a has been analyzed and the mole fraction profile has been found to obey the following function of y alone: a. Assuming a constant value for the diffusivity, Dab = Dabo, and...

A solid containing species a has been analyzed and the mole fraction profile has been found to obey the following function of y alone:

a. Assuming a constant value for the diffusivity, Dab = Dabo, and a dilute solution of a in b, has the system reached a steady state, i.e., does it obey the continuity equation in one dimension?

b. Assuming a diffused through stagnant b (Nb ≈ 0) and has reached steady state, what can you say about how the diffusivity varies as a function of composition?