SDS Volume (4639)

Volume 73. Metal and Ammonium Formate Systems, p None

Original Measurements

Balarew, C. C.; Vassileva, V. Z.; Compt. Rend. Acad. Bulg. Sci. 43, 51-4 (1990).

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, for 15-20 hrs. The $\ce{Co^{2+}}$ content of the liquid and solid phases was determined complexometrically using Complexon III at pH 5.5-6 with Xylenol Orange as indicator after removing $\ce{Zn^{2+}}$ with an ion exchange resin. The sum of $\ce{Co^{2+}}$ and $\ce{Zn^{2+}}$ was determined complexometrically by back titration with $\ce{ZnSO4}$ at pH 5.5-6.0 using Xylenol Orange as indicator. The composition of the suction-dried mixed crystals was determined by the algebraic indirect identification of the solid phase composition method [1].

Source and Purity of Materials:

1. The reagents used were of p.a. grade. Cobalt and zinc formates were prepared by the action of dilute formic acid with cobalt and zinc normal or basic 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).