Book excerpt: Properties of Aqueous Solutions of Electrolytes is a handbook that systematizes the information on physico-chemical parameters of multicomponent aqueous electrolyte solutions. This important data collection will be invaluable for developing new methods for more efficient chemical technologies, choosing optimal solutions for more effective methods of using raw materials and energy resources, and other such activities. This edition, the first available in English, has been substantially revised and augmented. Many new tables have been added because of a significantly larger list of electrolytes and their properties (electrical conductivity, boiling and freezing points, pressure of saturated vapors, activity and diffusion coefficients). The book is divided into two sections. The first section provides tables that list the properties of binary aqueous solutions of electrolytes, while the second section deals with the methods for calculating their properties in multicomponent systems. All values are given in PSI units or fractional and multiple units. Metrological characteristics of the experimental methods used for the determination of physico-chemical parameters are indicated as a relative error and those of the computational methods as a relative error or a root-mean square deviation.