Solubility equations for the ethylsulphates of trivalent Y, Pm, Pu, Am and Cm as determined by co-crystallization

Abstract

Assuming that the correlation between the cocrystallization coefficients and solubilities of the co-crystallizing ethylsulphates in the [(Ln,M) (H2O)9] (C2H5SO4)3−H2O system is valid when M is changed from lanthanides into the title elements, the solubilities of the ethylsulphates of trivalent Y, Pm, Pu, Am and Cm in water at 288–318 K have been determined “from the matrix”. The solubilities of Y, Pm, Pu, Am and Cm ethylsulphates and of all the lanthanide ethylsulphates are given in the form of smoothing equations of the lg molality=A+B/T type. From the B parameters of the solubility equations the enthalpies of solution have been estimated. The crystallization behaviour of yttrium in the ethylsulphate system is between that of holmium and that of erbium.