Given this concentration profile, I am to (1) determine at which side substance A will diffuse out of the membrane and (2) chose one of the following profiles below which represents the concentration of a substance A at steady-state.
(1) Diffusion occurs from an area of high concentration to an area of low concentration. Therefore, substance A would diffuse from the left to the right. However, in the question when they ask "at which side will the substance diffuse out of the membrane", should I answer at the right side or that the substance stays within the membrane?
(2) I know that the concentration profile at steady-state should be linear, however I'm wondering what the difference between (A) and (B) is. I assume that (A) is the correct answer to this question since substance A has a higher concentration than the concentrations at the membrane wall and hence the slope should start a little above the concentration at the wall. Is this correct or does steady-state affect the concentration profile of the substance?