uudelleenkiteytys

Uudelleenkiteytys refers to the process of recrystallization, a common laboratory technique used to purify solid compounds. The principle behind uudelleenkiteytys is based on the difference in solubility of the desired compound and its impurities in a chosen solvent at different temperatures. Ideally, the desired compound should be highly soluble in the solvent at elevated temperatures but poorly soluble at cooler temperatures, while the impurities should either remain soluble at low temperatures or be insoluble at high temperatures.

To perform uudelleenkiteytys, the impure solid is dissolved in a minimum amount of hot solvent. As the solution cools, the solubility of the desired compound decreases, causing it to crystallize out of the solution in a purer form. Impurities that are more soluble will remain dissolved in the mother liquor, while those that are less soluble might be removed by hot filtration before cooling. Once crystallization is complete, the pure crystals are separated from the mother liquor by filtration and then dried. This method is widely applicable in organic and inorganic chemistry for obtaining pure samples of solid substances.