Equilibrium Constants of Liquid-liquid Distribution Reactions Introduction, and Part 1: Organophosphorus Extractants focuses on the numerical representations, formulas, reactions, and characteristics of equilibrium constants of organophosphorus extractants. The text underscores that only a number of papers focusing on equilibrium constants for distribution reactions involving metal complexes are published before 1947. The book also states that no equilibrium constants have been reported on several organophosphorus extractants although they are used in practical extraction work. The publication provides a list of extractants, ligands, and metal ions. These include distribution and dissociation of extractants; dimerization and aggregation of extractants; homogeneous equilibria of extractants with metal ions; extraction of metal ions with extractants as ligands; and reactions of extractants with diluents and other solvents. The manuscript also highlights reactions, temperature, and equilibrium constants. The book is a valuable source of data for readers interested in the equilibrium constants of organophosphorus extractants.