A simple simulation that shows how a sodium chloride crystal dissolves.
Fantastic resource, helps pupils visualise what is happening at a particle level.
sorry but this does not show hydration by the water molecules. it does not show the intermolecular attractions between the sodium ions and the negatively charged end of the water molecule (oxygen), or the intermolecular attraction between the chlorine ions and the positively charged end of the water moleucule (Hydrogens). The water molecules should be shown surrounding each ion, which is what happens at the particulate level.
Agreed. In this simulation there is a very weak hydration effect, but it is much too small to be representative of real life.
In the simulation, each positive attracts each negative, each negative attracts each positive, positive charges repel each other, and negative charges repel each other. The net result is a crystal that dissolves only if the temperature is great enough to cause the ions in the crystal lattice to separate from each other.
I believe the reason that hydration complexes don’t form is that I am mapping 3D Coulombic forces into 2D, and attempting to run a simulation. In this simulation, the attractive/repulsive forces are actually 2D, and as a result, are not dropping off according to 1/r^2. The net result is that the hydration complexes around each ion don’t form as cleanly as they do in real life (3D).
When I get some time I will try to go back and make a true 3D model of the crystal and water molecules. Hopefully this will fix the problem of the hydration complexes not forming.
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