Abstract
Under kinetic conditions the rate of extraction depends on the rate of one or two slow reactions in the aqueous phase with the ion A– or the molecule HA and also on the rate of reaction in the aqueous phase not involving the extractant. This has been examined for the extraction of trace amounts of bivalent and tervalent elements from aqueous solutions of their salts by solutions of an acid HA in organic solvents. The rate of extraction varies in a complex manner both with the rate constants for the corresponding reactions and with the stability constants of the complex ions formed; for this reason, studies on the mechanism of the reactions determining the rate of extraction in which no account was taken of complex formation in general give erroneous results. The possibility of using the proposed methods to determine the mechanism of the extraction of macroamounts of a univalent element has been demonstrated.
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