The Solvent Extraction Behavior of Inorganic Compounds. IV. Variation of the Distribution Quotient with Chloride, Hydrogen Ion Held Constant

Abstract

The variation in the distribution quotient for tracer indium(III) distributing between the oxygenated solvents, diethyl, butyl ethyl, dibutyl and BETA , BETA '-dichlorodiethyl ether, methyl isobutyl and diisobutyl ketone, dibutyl phthalate, methyl benzoate, methyl salicylate, 2-ethylhexanol and decanol, and aqueous solutions of hydrochloric acid, in which the concentration of HCl was varied while keeping the total ionic strength constant with HClO/sub 4/ or HNO/sub 3/, was studied. The results are compared with the behavior expected from expressions derived for D and d log D/d log STAHCl!. It is shown that certain aspects of the variation in D are indeed indicated by the derived expressions, particularly a common ion'' effect when the ion InCl/sub 4/sup-/ is the principal organic phase indium-containing species and an increase in D when ion associations containing InCl/sub 4//sup -/ are possible in the organic phase. The remaining major effect is interpreted on the basis of a previous suggestion that the availability, or non-availability, of water in the aqueous phase for solvating ionic species is an important factor in the extraction process. These considerations are not restricted to the indium(III) chloride system, but appear to hold generally for those metal halides which extract into oxygenated organic solventsmore » as the anions of strong acids. (auth)« less