SDS Volume (4628)
Volume 73. Metal and Ammonium Formate Systems, p None
Original Measurements
Balarew, C.; Stoilova, D.; Vassileva, V.; J. Solid State Chem. 57, 260-6 (1985).
Variables:
Room Temp: Composition at 25 °C
Prepared by:
St. Trendafilova, Chr. Balarew
Method/Apparatus/Procedure:
The method used was the isothermal decrease of supersaturation. The $\ce{Mn^{2+}}$ content of the liquid and solid phases was determined complexometrically at pH 9.5-1 0 using Eriochrome Black T as indicator after masking $\ce{Zn^{2+}}$ as cyanide. The sum of $\ce{Mn^{2+}}$ and $\ce{Zn^{2+}}$ was also determined complexometrically using Xylenol Orange at pH 5.5 as indicator. The composition of the suction-dried solid phase was calculated using the algebraic indirect identification of solid phase composition method [1]. The mixed crystals were also studied by X-ray diffraction.
Source and Purity of Materials:
- The reagents used were of p. a. grade. The manganese and zinc formates were prepared by action of dilute formic acid on manganese and basic zinc carbonates, respectively.
Estimated Errors:
Ambient temperature: Not given.
Mass concentration (m/v) (1): The solubility of the salts was determined in a slight excess of formic acid (about 2%) to suppress salt hydrolysis.
References
1 Trendafelov, D.; Balarew, Chr.; Comm. Dept. Chem. Bulg. Acad. Sci. 1 , 73 (1968).
Components:
- Manganese(II) formate, $\ce{ Mn(CHO2)2 }$; [3251-96-5] NIST WebBook
- Zinc formate, $\ce{ Zn(CHO2)2 }$; [557-41-5] NIST WebBook
- Water, $\ce{ H2O }$; [7732-18-5] NIST WebBook
Experimental Data
Solubility values in the Mn(CHO2)2-Zn(CHO2)2-H2O system at 25°C.
| 100w1 | 100w2 | D1|2 | D2|1 | m1 (mol/kg) | m2 (mol/kg) | Phase (s) () |
|---|---|---|---|---|---|---|
| 6.28 | 0.00 | - | - | 0.462 | 0.00 | A |
| 5.38 | 1.29 | 0.68 | 1.47 | 0.398 | 0.089 | B |
| 4.20 | 2.02 | 0.74 | 1.36 | 0.309 | 0.139 | B |
| 2.50 | 3.20 | 0.59 | 1.70 | 0.183 | 0.218 | B |
| 0.00 | 5.38 | - | - | 0.00 | 0.366 | C |
(a) The molality values were calculated by the compiler.
(b) The solid phases are: A = Mn(CHO2)2·2H2O; B = (Mn,Zn)(CHO2)2·2H2O; C = Zn(CHO2)2·2H2O.
