Liquid-liquid extraction is a technique that exploits the differential solubilities of compounds between two liquid phases to extract the compound we want into a single phase. The liquids being used must be immiscible, meaning that they form two separate layers when placed in the same container. The goal is to have our compound of interest dissolved exclusively in a single liquid phase and also to have it be the only chemical compound dissolved in that phase. If this can be achieved, the liquid layer containing the desired compound is then separated and the solvent is removed, yielding the pure substance.