Author/Authors :
Ciavatta، Liberato نويسنده , , Tommaso، Gaetano De نويسنده , , Iuliano، Mauro نويسنده ,
Abstract :
The solubility, at 25°C, of calcium citrate, Ca3(C6H5O7)2. 4H2O, in NaClO4 solutions in the molality (m) range 0–3.5, has been determined by potentiometric titration with EDTA, using the Hg2+/Hg half-cell. The increase of solubility with m has been explained with the specific interaction theory by assuming, for Ca3(C6 H5 O7)2.4 H2 O (s) 3Ca2+ + 26H55O73-, log Ks0= -17.81 ± 0.03 and the interaction coefficient between Na+ and C6H5O73- ions equal to 0.08 ± 0.03 -(0.06 ± 0.01)m. This coefficient allows the extrapolation to the infinite dilution reference state of stability constants determined in concentrated ionic media. Results of calculations compare well with those of the literature.
