Contribution to the Thermodynamics of Sc~(3+), Y~(3+), La~(3+) and Trivalent Lanthanide Cations in the Two-Phase Water-Nitrobenzene Extraction System

摘要

From the exchange extraction constants corresponding to the general equilibrium M~(3+)(aq) + 3H~+(nb) <=> M~(3+)(nb) + 3H~+(aq) occurring in the two-phase water-nitrobenzene system (M~(3+) = Sc~(3+), Y~(3+), La~(3+), Ce~(3+), Pr~(3+), Nd~(3+), Sm~(3+), Eu~(3+), Gd~(3+), Tb~(3+), Dy~(3+), Ho~(3+), Er~(3+), Tm~(3+), Yb~(3+), Lu~(3+); aq = aqueous phase, nb = nitrobenzene phase), the individual extraction constants of 16 trivalent metal cations were calculated. It was found that these individual extraction constants in the mentioned two-phase system increase in the following cation order: Sc~(3+) < Yb~(3+)< Ho~(3+) < Er~(3+) < Tm~(3+), Lu~(3+) < Y~(3+), Dy~(3+) < Tb~(3+) < Gd~(3+) < Eu~(3+) < Sm~(3+) < Nd~(3+) < Pr~(3+) < La~(3+), Ce~(3+).