what happens when a saturated solution cools?!?

Question

does is crystalize or what does it do??

Answer 1

if a saturated solution is left to cool undisturbed it will form a super saturated solution- a seed crystal can then be added and will act as a template causing the solution to crystallize rapidly

Answer 2

It depends on the solubility of the solute (the stuff dissolved in it).
For some, the solubility stays the same regardless of temperature, like sodium chloride. So cooling would not do much.
For most other mineral salts, the solubility decreases as temperature decreases, so cooling will cause some of the solute to precipitate out.
For most gases on the other hand, cooling actually increases solubility.

As for crystallization, when the solution can no longer hold onto the solute, the solute precipitate out. This often occurs on impurities and inconsistencies like the micro-cracks of the container. However, if there is a pre-existing crystal, and cooling is slow enough, the solute will crystallize on this 'seed' crystal. Smaller crystals will also form on the crystals that form on the micro-cracks.