What happens to a solute's potential energy during diffusion?

I was thinking, if you have a large amount of water, with an uneven solute concentration, diffusion will lead to an even concentration of solute throughout the solution.


Intuitively,that would mean that our system initially has a large amount of potential energy, and that it decreases to a minimum.


![Text](https://upload.wikimedia.org/wikipedia/commons/thumb/1/12/Diffusion.svg/800px-Diffusion.svg.png)


I feel like this raises two questions :


Firstly, from which force does this inital "osmotic" potential energy derive ?


Secondly, under what form is this potential energy realeased once concentration equilibrium is reached ?


What's more, if you consider a cell membrane with a great concentration difference between one side, and another, simple diffusion will lead solute molecules to pass through the membrane. So, in order to pass through the membrane, a solute would have to expend potential energy : the diffusion reaction would have a certain activation energy.
Under what form is this energy then dissipated ? It would first become kinetic enrgy, allowing the solute to pass through the membrane, but what form would it then take ? Simply heat energy ?


Any answer would be greatly appreciated, thanks.




Energy *can* be recovered across a concentration gradient, as in [osmotic power production](https://en.wikipedia.org/wiki/Osmotic_power).


But you ask, if I understand correctly what happens if the energy is *not* harvested? The same thing that would happen if you dropped a weight:


* If the weight is attached so as to spin a generator, then the potential energy can be converted to electric energy.
* If the weight is allowed to impact a surface, instead, then the potential energy is converted to heat.


If economics is considered the [dismal science](https://en.wikipedia.org/wiki/The_dismal_science), thermodynamics is equally grim. Consider [Ginsberg's Theorem](https://www.barrypopik.com/index.php/new_york_city/entry/you_cant_win_you_cant_break_even)


1. You can’t win.
2. You can’t break even.
3. You can’t get out of the game.


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