Home
Introduction
Search Menu
IUPAC Series (PDF)
Reference
Version History
About the Project
Disclaimer
Contact Us
Acknowledgements
IUPAC-NIST Solubility Database
NIST Standard Reference Database 106
Solubility System:
Manganese formate with Cobalt formate and Water
Components:
(1) Cobalt formate; Co(CHO2)2; [544-18-3]
NIST Chemistry WebBook
for detail
(2) Manganese formate; Mn(CHO2)2; [3251-96-5]
NIST Chemistry WebBook
for detail
(3) Water; H2O; [7732-18-5]
NIST Chemistry WebBook
for detail
Original Measurements:
Balarew, C.; Stoilova, D.; Vassileva, V., J. Solid State Chem. 57, 260-6 (1985).
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 Mn(CHO
2
)
2
-Co(CHO
2
)
2
-H
2
O system at 25 °C.
Chemical
1
Phase
Mass Fraction w
1
m
1
[mol kg-1]
a
Chemical
2
Mass Fraction w
2
m
2
[mol kg-1]
a
Solid Phase(s)
b
Distribution Coefficient
Mn2+/Co2+
Distribution Coefficient
Co2+/Mn2+
Mn(CHO2)2
Liquid
6.28
0.462
Co(CHO2)2
0.00
0.00
A
---
---
Mn(CHO2)2
Liquid
5.38
0.398
Co(CHO2)2
1.29
0.093
B
0.24
4.17
Mn(CHO2)2
Liquid
3.95
0.287
Co(CHO2)2
1.00
0.071
B
0.27
3.74
Mn(CHO2)2
Liquid
3.84
0.279
Co(CHO2)2
1.11
0.078
B
0.28
3.57
Mn(CHO2)2
Liquid
2.28
0.163
Co(CHO2)2
1.49
0.104
B
0.21
4.93
Mn(CHO2)2
Liquid
0.00
0.00
Co(CHO2)2
2.44
0.168
C
---
---
Notes:
a
The molality values were calculated by the compilers.
b
The solid phases are: A = Mn(CHO
2
)
2
•2H
2
O; B = (Mn,Co)(CHO
2
)
2
•2H
2
O; C = Co(CHO
2
)
2
•2H
2
O.
Method/Apparatus/Procedure:
The method used was the isothermal decrease of supersaturation, under stirring, for 15-20 hrs. The Mn
2+
content of the liquid and solid phases was determined complexometrically at
p
H 9.5-10 using Eriochrome Black T as indicator after masking CO
2+
as cyanide. The sum of Mn
2+
and CO
2+
was also determined complexometrically using Xylenol Orange 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 cobalt formates were prepared by action of dilute formic acid on the manganese and cobalt carbonates, respectively.
Estimated Errors:
Solubility: The solubility of the salts was determined in a slight excess of formic acid (about 2%) to suppress salt hydrolysis.
Temperature: Not given.
References:
1
D. Trendafelov and Chr. Balarew, Comm. Dept. Chem. Bulg. Acad. Sci.
1
, 73 (1968).