IUPAC-NIST Solubility Database
NIST Standard Reference Database 106


Glass Ball as Bullet Solubility System: Strontium formate with Copper formate and Water

Components:
   (1) Copper formate; Cu(CHO2)2; [544-19-4]  NIST Chemistry WebBook for detail
   (2) Strontium formate; Sr(CHO2)2; [592-89-2]  NIST Chemistry WebBook for detail
   (3) Water; H2O; [7732-18-5]  NIST Chemistry WebBook for detail

Original Measurements:
   Vasileva, V., Cryst. Res.Technol. 30, 339-343 (1995).

Variables:

   Concentration = Composition at 25 ºC

Prepared By:
   Chr. Balarew and St. Trendafilova

Experimental Data:   (Notes on the Nomenclature)
(Please see footnotes following the table(s).)
  
Solubility values in the Sr(CHO2)2-Cu(CHO2)2-H2O system at 25 °C.
Chemical1PhaseMass Fraction w1m1 [mol kg-1]aChemical2Mass Fraction w2m2 [mol kg-1]aSolid Phase(s)b
Cu(CHO2)2Liquid8.800.628Sr(CHO2)20.000.00A
Cu(CHO2)2Liquid7.700.566Sr(CHO2)23.770.374A
Cu(CHO2)2Liquid7.600.571Sr(CHO2)25.750.374A
Cu(CHO2)2Liquid8.070.630Sr(CHO2)28.630.583A
Cu(CHO2)2Liquid8.950.725Sr(CHO2)210.700.750A
Cu(CHO2)2Liquid9.090.742Sr(CHO2)211.180.789eutonic
Cu(CHO2)2Liquid9.120.745Sr(CHO2)211.150.787eutonic
Cu(CHO2)2Liquid8.520.688Sr(CHO2)210.900.761B
Cu(CHO2)2Liquid7.930.635Sr(CHO2)210.800.748B
Cu(CHO2)2Liquid7.000.557Sr(CHO2)211.160.767B
Cu(CHO2)2Liquid4.900.380Sr(CHO2)211.150.747B
Cu(CHO2)2Liquid3.820.292Sr(CHO2)210.990.726B
Cu(CHO2)2Liquid3.220.245Sr(CHO2)211.350.748eutonic
Cu(CHO2)2Liquid2.510.190Sr(CHO2)211.720.769C
Cu(CHO2)2Liquid0.000.00Sr(CHO2)212.200.782C
Notes:
   a  The molality values were calculated by the compilers.
   b  The solid phases are: A = Cu(CHO2)2•4H2O; B = CuSr(CHO2)4•8H2O; C = Sr(CHO2)2•2H2O.

Method/Apparatus/Procedure:
   The solubility in the system was studied by the Khlopin method of isothermal decrease of supersaturation.1 Equilibrium was reached in 10-15 hr. Cu2+ was determined complexometrically at pH 5.5-6.0 using Xylenol Orange as indicator. Sr2+ was determined also complexometrically at pH 11 using Thymolphtalexon as indicator. The solid phase composition was determined by the graphic method of Schreinemakers' for wet residues. X-ray diffraction analysis, DT and TG analysis were also used.

Source and Purity of Materials:
   The formates of copper and strontium were prepared by dissolving copper carbonate, and strontium carbonate respectively, in diluted formic acid. The reagents used were "p.a.''.

Estimated Errors:

   Temperature: Not given.

References:
   1Chr. Balarew, V. Karaivanova, and T. Oikova, Comm. Dept. Chem. Bulg. Acad. Sci. 3, 637 (1970).