Crystallization separates salt from water by evaporating the water, leaving salt crystals behind.
Here's a breakdown of the process:
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Dissolve the Salt: Begin by dissolving the salt in water. Stir until no more salt will dissolve. This creates a salt solution.
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Heat the Solution: Gently heat the salt solution. The goal is to evaporate the water, but not to boil the solution vigorously. Heat it to about halfway (as shown in the video reference), or until you see crystals starting to form at the edges of the container.
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Evaporate the Water: Continue heating until most of the water has evaporated. You'll notice salt crystals beginning to form and grow.
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Cool and Crystallize: Remove the heat and allow the remaining solution to cool slowly. As the solution cools, more salt will come out of solution and form larger, purer crystals. Slow cooling promotes the formation of larger, well-defined crystals.
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Collect the Crystals: Once the solution has cooled and crystallization is complete, carefully pour off any remaining liquid (the "mother liquor"). You can then collect the salt crystals from the container. You may want to rinse the crystals with a small amount of distilled water to remove any remaining impurities, and then allow them to dry.
In essence, crystallization relies on the principle that the solubility of salt in water decreases as the temperature decreases. By evaporating the water and then cooling the solution, we force the salt to come out of solution and form crystals.
