Mass Transfer

Step 1: State Fick's First Law of Diffusion. The law describes the relationship between the flux of a component and its concentration profile.

Step 2: Write the mathematical expression for the law. Where:


is the mass flux (mass flowing per unit area per unit time).
is the diffusion coefficient (a proportionality constant).
is the concentration gradient, which is the change in concentration (dC) over a change in position (dx). \end{itemize} The law explicitly states that the flux is directly proportional to the concentration gradient. The negative sign indicates that diffusion occurs from a region of higher concentration to a region of lower concentration.