Ion mobilities of trivalent f-elements in aqueous electrolytes

Individual ion mobilities usub(Me3+)0 of carrier-free La(III), kEu(III), Gd(III), Tb(III), Tm(III) Yb(III), Lu(III), Am(III) and Cf(III) were measured in dependence on the pH of aqueous perchlorate electrolytes at μ = 0.10,T = 298.1 K. Two different levels of ion mobilities were found in neutral (Ph > 5) and acidic (pH < 2.5) solutions for most of the cations investigated. Exceptions are Eu(III) and Cf(III). The observed relationships between the crystallographic radii of the trivalent f-elements and their usub(Me3+)0 data in acidic and neutral electrolytes confirm the hypothesis of S-shaped changes of hydratation parameters within the lanthanide and actinide series. (orig.)