SDS Volume (4618)
Volume 73. Metal and Ammonium Formate Systems, p None
Original Measurements
Vasileva, V.; Cryst. Res. Technol. 30, 339-343 (1995).
Variables:
Room Temp: Composition at 50 °C
Prepared by:
St. Trendafilova, Chr. Balarew
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. $\ce{Cu^{2+}}$ was determined complexometrically at pH 5.5-6.0 using Xylenol Orange as indicator. $\ce{Sr^{2+}}$ was also determined 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:
Ambient temperature: Not given.
References
1 Balarew, Chr.; Karaivanova, V.; Oikova, T.; Comm. Dept. Chem. Bulg. Acad. Sci. 3, 637 (1970).
Components:
- Strontium formate, $\ce{ Sr(CHO2)2 }$; [592-89-2] NIST WebBook
- Copper formate, $\ce{ Cu(CHO2)2 }$; [544-19-4] NIST WebBook
- Water, $\ce{ H2O }$; [7732-18-5] NIST WebBook
Experimental Data
Solubility values in the Sr(CHO2)2-Cu(CHO2)2-H2O system at 50°C.
| 100w2 | 100w1 | m2 (mol/kg) | m1 (mol/kg) | Phase (s) () |
|---|---|---|---|---|
| 25.17 | 0.00 | 2.190 | 0.00 | A |
| 23.35 | 6.73 | 2.74 | 0.542 | A |
| 22.81 | 12.30 | 2.291 | 1.068 | A |
| 24.01 | 17.50 | 2.673 | 1.684 | A |
| 25.07 | 19.20 | 2.929 | 1.939 | Eutonic |
| 24.31 | 19.16 | 2.800 | 1.902 | B |
| 21.98 | 19.20 | 2.433 | 1.837 | B |
| 19.86 | 19.53 | 2.133 | 1.814 | B |
| 17.51 | 19.60 | 1.813 | 1.754 | B |
| 15.68 | 19.90 | 1.585 | 1.713 | B |
| 14.10 | 21.02 | 1.417 | 1.826 | Eutonic |
| 12.60 | 20.23 | 1.221 | 1.695 | C |
| 8.01 | 18.13 | 0.706 | 1.382 | C |
| 4.75 | 17.76 | 0.399 | 1.290 | C |
| 0.00 | 17.16 | 0.00 | 1.166 | C |
(a) The molality values were calculated by the compilers.
(b) The solid phases are: A = Cu(CHO2)2·2H2O; B = CuSr(CHO2)4·4H2O; C = Sr(CHO2)2·2H2O.
