IUPAC-NIST Solubilities Database

IUPAC-NIST Solubility Database
NIST Standard Reference Database 106

Solubility System: Nickel formate with Water

Components:
   (1) Nickel formate; Ni(CHO2)2; [3349-06-2]  NIST Chemistry WebBook for detail
   (2) Water; H2O; [7732-18-5]  NIST Chemistry WebBook for detail

Original Measurements:
   Balarew, C.; Vassileva, V.; Stoilova, D., Comm. Dept. Chem. Bulg. Acad. Sci. 14, 57 (1981).

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 polytherm of the Ni(CHO₂)₂-H₂O system.
t/°C	Phase	Mass Fraction w₁	m₁ [mol kg-1]^a	Solid Phase(s)^b
10	Liquid	1.72	0.118	A
15	Liquid	1.86	0.127	A
20	Liquid	2.00	0.137	A
25	Liquid	2.13	0.146	A
30	Liquid	2.29	0.158	A
35	Liquid	2.46	0.170	A
40	Liquid	2.55	0.176	A
45	Liquid	2.69	0.186	A
50	Liquid	2.78	0.192	A
55	Liquid	2.89	0.200	A
60	Liquid	3.04	0.211	A
65	Liquid	3.17	0.220	A
70	Liquid	3.30	0.229	A
75	Liquid	3.48	0.242	A
80	Liquid	3.53	0.246	A

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

Method/Apparatus/Procedure:
   The decrease of supersaturation was studied isothermally in about a 2% excess of formic acid to suppress hydrolysis of the salt. Equilibrium was reached in 2 days. The nickel content of both the liquid and solid phases was determined by complexometric back-titration at pH 5.5-6 using Xylenol orange as indicator. The composition of the solid phase was also determined by x-ray diffraction and microscopic observations.

Source and Purity of Materials:
   Nickel formate was prepared by dissolving basic nickel carbonate in dilute formic acid.

Estimated Errors:
   Solubility: The solubilities were determined in a slight excess of formic acid (about 2%) in order to inhibit salt hydrolysis.