IUPAC-NIST Solubilities Database

IUPAC-NIST Solubility Database
NIST Standard Reference Database 106

Solubility System: Iron formate with Water

Components:
   (1) Iron formate; Fe(CHO2)2; [3047-59-4]  NIST Chemistry WebBook for detail
   (2) Water; H2O; [7732-18-5]  NIST Chemistry WebBook for detail

Original Measurements:
   Vasileva, V.; Karapetkova, A., Bulgarian Chemical Communications 28, 151-9 (1995).

Variables:
   Temperature = 10 ºC to 80 ºC

Prepared By:
   Chr. Balarew and St. Trendafilova

Experimental Data:   (Notes on the Nomenclature)
(Please see footnotes following the table(s).)

Solubility of the Fe(CHO₂)₂ - H₂O system
t/°C	Phase	Mass Fraction w₁	m₁ [mol kg-1]^a	Solid Phase(s)^b
10	Liquid phase Fe(CHO2)2	3.48	0.247	A
15	Liquid phase Fe(CHO2)2	3.72	0.264	A
20	Liquid phase Fe(CHO2)2	4.05	0.289	A
30	Liquid phase Fe(CHO2)2	4.41	0.316	A
35	Liquid phase Fe(CHO2)2	4.65	0.334	A
40	Liquid phase Fe(CHO2)2	4.85	0.349	A
45	Liquid phase Fe(CHO2)2	5.08	0.362	A
50	Liquid phase Fe(CHO2)2	5.22	0.377	A
55	Liquid phase Fe(CHO2)2	5.50	0.398	A
60	Liquid phase Fe(CHO2)2	5.70	0.414	A
65	Liquid phase Fe(CHO2)2	5.89	0.429	A
70	Liquid phase Fe(CHO2)2	6.12	0.447	A
75	Liquid phase Fe(CHO2)2	6.27	0.458	A
80	Liquid phase Fe(CHO2)2	6.50	0.476	A

Notes:
   ^a  These values were calculated by the compilers.
   ^b  The solid phase is: A = Fe(CHO₂)₂•2H₂O.

Method/Apparatus/Procedure:
   The isothermal solubility method was used. Equilibrium was reached in 5-7 hrs. in an argon atmosphere. Fe²⁺ was first oxidized to Fe³⁺ with H₂O₂ and then determined complexometrically at pH 1.5 and sulfosalicylic acid as indicator. The solid phase composition was determined by the graphic method of Schreinemakers for wet residues.¹ X-ray diffraction analysis was also used.

Source and Purity of Materials:
   Iron formate was prepared by dissolution of iron powder in dilute formic acid. All reagents were p.a. grade.

Estimated Errors:

References:
   ¹F. A. Schreinemakers, Z. Phys. Chem. 11, 76 (1983); 55 73 (1906).