Interaction of europium oxide (II) with NaBr-Nal (0.31:0.69) melt at 973 K

T.P. Rebrova, V.L. Cherginets


Solubility product (Ks,EuO=3.6∙10-9 mol2∙kg-2) and dissociation constant of EuO (KEuO=2.9∙10-6 mol∙kg-1) in molten NaBr-NaI (0.31:0.69) at 973 K are determined by potentiometric method. The sum of concentrations of ionic (Eu2++O2 ) and non-dissociated forms (EuO) in the saturated solution (s.s.) is 1.35∙10-3 mol∙kg-1, that is somewhat higher than in NaI melt. The increase of Eu2+ and O2- in s.s. of EuO can be explained by the presence in the mixed melt of harder Pearson’s base (Br-).