IUPAC-NIST Solubilities Database

IUPAC-NIST Solubility Database
NIST Standard Reference Database 106

Solubility System: Diammonium hydrogenphosphate with Urea nitrate and Water

Components:
   (1) Diammonium hydrogenphosphate; (NH4)2HPO4; [7783-28-0]  NIST Chemistry WebBook for detail
   (2) Urea nitrate; CO(NH2)2.HNO3; [17687-37-5]  NIST Chemistry WebBook for detail
   (3) Water; H2O; [7732-18-5]  NIST Chemistry WebBook for detail

Original Measurements:
   Nabiev, M.N.; Tukhtaev, S., Narkhodzaev, A.Kh., and Yunusov, D.Kh., Zh. Neorg. Khim. 21, 3152 (1976).

Variables:

   Concentration = Temperature and composition.

Prepared By:
   J. Eysseltová

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

Nonvariant and monovariant points in the (NH₄)₂HPO₄-CO(NH₂)₂.HNO₃-H₂O system.
t/°C	Chemical₁	10² * Mass Fraction w₁	m₁ [mol/kg]^(a)	Chemical₂	10² * Mass Fraction w₂	m₂ [mol/kg]^(a)	Chemical₃	10² * Mass Fraction w₃	Solid Phase(s)^(b)
-2.8	CO(NH2)2@HNO3	8.0	0.7	(NH4)2HPO4	0.0	0.0	H2O	92.0	ice + A
-3.6	CO(NH2)2@HNO3	9.8	0.9	(NH4)2HPO4	2.0	0.2	H2O	88.2	ice + A
-8.0	CO(NH2)2@HNO3	15.8	1.7	(NH4)2HPO4	8.4	0.8	H2O	75.8	ice + A
-12.4	CO(NH2)2@HNO3	17.8	2.0	(NH4)2HPO4	11.0	1.2	H2O	71.2	ice + A + B
-8.5	CO(NH2)2@HNO3	23.0	3.0	(NH4)2HPO4	15.4	1.9	H2O	61.6	A + B
-5.5	CO(NH2)2@HNO3	32.0	5.4	(NH4)2HPO4	20.0	3.2	H2O	48.0	A + B
-7.0	CO(NH2)2@HNO3	32.6	5.6	(NH4)2HPO4	20.2	3.2	H2O	47.2	A + B
30.0	CO(NH2)2@HNO3	40.0	9.0	(NH4)2HPO4	24.0	5.0	H2O	36.0	A + B
-9.0	CO(NH2)2@HNO3	12.4	1.4	(NH4)2HPO4	17.4	1.9	H2O	70.2	ice + B + C
-7.2	CO(NH2)2@HNO3	8.0	0.9	(NH4)2HPO4	20.0	2.1	H2O	72.0	ice + C
-5.5	CO(NH2)2@HNO3	0.0	0.0	(NH4)2HPO4	25.0	2.5	H2O	75.0	ice + C
-10.0	CO(NH2)2@HNO3	12.0	1.5	(NH4)2HPO4	22.0	2.5	H2O	66.0	B + C
-17.5	CO(NH2)2@HNO3	11.0	1.4	(NH4)2HPO4	26.6	3.2	H2O	62.4	B + C + D
-10.5	CO(NH2)2@HNO3	6.8	0.9	(NH4)2HPO4	31.3	3.8	H2O	61.9	C + D
15.0	CO(NH2)2@HNO3	0.0	0.0	(NH4)2HPO4	39.2	4.9	H2O	60.8	C + D
-11.0	CO(NH2)2@HNO3	13.8	2.0	(NH4)2HPO4	31.0	4.3	H2O	55.2	B + D
-2.0	CO(NH2)2@HNO3	15.6	2.5	(NH4)2HPO4	33.6	5.0	H2O	50.8	B + D
28.0	CO(NH2)2@HNO3	19.6	4.0	(NH4)2HPO4	40.2	7.6	H2O	40.2	B + D
49.0	CO(NH2)2@HNO3	22.2	5.4	(NH4)2HPO4	44.4	10.1	H2O	33.4	B + D

Notes:
   Table 1  ^a  The molalities were calculated by the compiler.
   Table 1  ^b  The solid phases are: A=(CO(NH₂)₂·HNO₃; B=NH₄H₂PO₄; C=(NH₄)₂HPO₄·2H₂O; D=NH₄NO₃; E=(NH₄)₂HPO₄.

Method/Apparatus/Procedure:
   Presumably some sort of visual polythermic method was used (compiler), but no details are given.

Source and Purity of Materials:
   Diammonium hydrogenphosphate was recrystallized before use. Urea nitrate was synthesized from urea and reagent grade nitric acid.

Estimated Errors:
   Solubility: No details are given.
   Temperature: No details are given.