Electrolyte and water activities in very concentrated solutions

New equations to calculate electrolyte activities in very concentrated aqueous solutions are proposed in the framework of the adsorption theory of electrolytes. They are based on additivity properties regarding the adsorption parameters which may be viewed as consequences of structural features of hydrate melts found to conform to the theory: preservation of the chemical species on mixing water and electrolytes, predominance of short range interactions, existence of short range order in connection with the presence of holes. (C) 2000 Elsevier Science Ltd. All rights reserved.