Then I am going to perform an experiment about rapid crystallization. I will prepare a supersaturated solution of
potassium nitrate. To do this I will heat some water to get the maximum amount of solute dissolved. Add more amount of solute … ie, potassium nitrate. It seems that it has dissolved all, then more solute … Potassium nitrate is mainly used as fertilizer. A little more… It seems that it wants to more … Even more … As you can see, the solubility of potassium nitrate in water when we are almost at 100 degrees celsius is very high. And now I will pour the solution in this glass Petri dish. I have spilled out a bit. We observe how the part that has been spilled has already crystallized practically all. By lowering the temperature, since at lower temperature It can not be maintained dissolved so much solute, so it crystallizes. Because we have put too much of potassium nitrate we can’t see the wood for the trees. Let’s repeat the experiment, but with a lower concentration of potassium nitrate so you can see how crystals grow in the solution. Time x20