Solvent Extraction Equilibrium
The equilibrium established when a solute is transferred between two immiscible liquid phases in a separating funnel.
Formula / equation
efficiency = P V₁ / (P V₁ + V₂)
Unit
Dimensionless
In depth
The fraction extracted depends on the partition coefficient and the volume ratio of the phases. Because each extraction leaves a fixed fraction behind, several small extractions are far more efficient than one large one, a result that follows directly from the multiplicative form of the recovery.
Examples in the real world
Three 10 mL extractions removing far more solute than a single 30 mL extraction of the same aqueous solution.