In liquid-liquid extraction, if two solvents are immiscible, what will be the result?

In liquid-liquid extraction, when two solvents are immiscible, they do not mix uniformly but instead form two distinct layers. This occurs because immiscible liquids have different densities and polarities, which prevents them from mixing at the molecular level. As a result, one solvent will typically form a layer on top of the other, depending on their respective densities—commonly, the less dense solvent will sit above the denser one.

This property is critical in liquid-liquid extraction processes, where the goal is to separate compounds based on their solubility in each solvent. The distinct layers allow for easier separation and collection of the desired compound from one of the solvent layers, enhancing the efficiency of the extraction process.

The other choices imply interactions or processes that would not occur in the case of immiscible solvents. Complete mixing would suggest that the solvents are miscible, which contradicts their immiscible nature. Evaporation relates to changes in physical state rather than the behavior of immiscible liquids. An emulsion would involve the dispersion of one liquid within another, usually requiring agitation, and is not a characteristic of immiscible solvents at rest.