Question

According to Fick's law of diffusion, the diffusion flux is proportional to:

• A. The concentration gradient
• B. The temperature gradient
• C. The pressure gradient
• D. The velocity of the fluid

Hint:

Remember: Fick’s law links flux with concentration gradient—not pressure, temperature, or velocity.

Answer 1

The Correct Option is A

Fick’s First Law of diffusion states that the rate of diffusion (diffusion flux) of a species is directly proportional to the negative gradient of concentration.
Mathematically, \[ J = -D \frac{dC}{dx} \] Where:
\( J \) = diffusion flux (amount of substance per unit area per unit time)
\( D \) = diffusion coefficient
\( \frac{dC}{dx} \) = concentration gradient
The negative sign indicates that diffusion occurs from a region of higher concentration to a region of lower concentration.
Hence, diffusion flux is proportional to the concentration gradient.