1) Solvent extraction is a technique used to separate components in a mixture based on differences in solubility between two immiscible liquid phases. 2) It involves transferring a solute from one liquid phase to another, such as transferring a compound from an aqueous phase to an organic phase like benzene. 3) The amount of solute extracted into each phase can be calculated using the partition coefficient K, which is a ratio of concentrations in the two phases at equilibrium.