Question

We're learning about flux and Fick's law and there's one point I'm having trouble understanding. Assuming we have a higher concentration of a species on one side of a membrane, I understand that increasing the concentration will increase the flux (net particle movement/(time*area)). We were told as well that increasing the concentration also decreases the time it takes to reach equilibrium. Why would that be?

Rephrased: If you have 10 particles on one side of the membrane and 0 on the other, it takes X amount of time to reach equilibrium (~ 5 particles on each side). If you have 10 million particles, why would it take
Thanks

Answer 1

The time it takes to reach equilibrium is influenced by the concentration gradient. Increasing the concentration of a species on one side of a membrane not only increases the flux but also decreases the time it takes to reach equilibrium due to the steepness of the concentration gradient.

Step-by-step explanation:

The time it takes to reach equilibrium is influenced by the concentration gradient. When there is a higher concentration of particles on one side of the membrane, the concentration gradient is steeper.

This means that there is a greater difference in concentration between the two sides, leading to a more rapid diffusion. As the concentration gradient decreases and the distribution of particles gets closer to equilibrium, the rate of diffusion slows down.

For example, if you have 10 particles on one side of the membrane and 0 on the other, it may take a certain amount of time (X) for the system to reach equilibrium, which is approximately 5 particles on each side. However, if you have 10 million particles, the concentration gradient is much larger, and diffusion is faster. Therefore, it would take a shorter amount of time to reach equilibrium compared to the scenario with 10 particles.

Overall, increasing the concentration of a species on one side of a membrane not only increases the flux but also decreases the time it takes to reach equilibrium due to the steepness of the concentration gradient.