“How can we purify a crystal by dissolving it?”
Crystals are some of the most omnipresent structures in the universe. However, often times such crystals will have impurities to be found inside their crystal lattice, changing the properties of the material. So what is one way that we could get rid of such an impurity? Well, let’s think about it. We know that crystal lattice element and the impurities are made from different molecules, therefore having different melting and cooling points. We also know that if we were to dissolve this compound into a hot solvent, we could effectively decouple the elements from one another. So what if we were to take these two concepts, combine them, and make a system in which the crystal with the impurity would be dissolved and then cooled down to the point that the crystal reforms but the impurity does not? Well, it turns out that this is a process known as recrystallization, and is used by chemists and material scientists to purify crystal elements.