IUPAC-NIST Solubility Database
NIST Standard Reference Database 106

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 Solubility System: Diammonium hydrogenphosphate with Urea, Ammonium nitrate and Water

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Components:
   (1) Ammonium nitrate; NH4NO3; [6484-52-2]  NIST Chemistry WebBook for detail
   (2) Diammonium hydrogenphosphate; (NH4)2HPO4; [7783-28-0]  NIST Chemistry WebBook for detail
   (3) Urea; CH4N2O; [57-13-6]  NIST Chemistry WebBook for detail
   (4) Water; H2O; [7732-18-5]  NIST Chemistry WebBook for detail

Original Measurements:
   Tudorovskaya, G.L.; Margolis, F.G., Khim. Prom. (Moscow) 1966, 42, 678.

Variables:

   Concentration = Composition at 50 ºC

Prepared By:
   J. Eysseltová

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

Part 1. Solubility in the (NH₄)₂HPO₄-NH₄NO₃-CO(NH₂)₂-H₂O system at 50 °C

Solution number	Chemical1	102 * Mass Fraction w1	m1 [mol/kg](a)	Chemical2	102 * Mass Fraction w2	m2 [mol/kg](a)	Chemical3	102 * Mass Fraction w3	m3 [mol/kg](a)	Chemical4	102 * Mass Fraction w4	Solid Phase(s)(b)
1	CO(NH2)2	0.000	0.000	NH4NO3	67.95	30.39	(NH4)2HPO4	4.12	1.12	H2O	27.93	A + B
2	CO(NH2)2	9.44	7.15	NH4NO3	65.77	37.36	(NH4)2HPO4	2.80	0.964	H2O	21.99	A + B
3	CO(NH2)2	16.65	14.51	NH4NO3	62.59	40.92	(NH4)2HPO4	1.65	0.654	H2O	19.11	A + B
4	CO(NH2)2	29.86	50.22	NH4NO3	58.77	74.16	(NH4)2HPO4	1.47	1.12	H2O	9.90	A + B
5	CO(NH2)2	38.74	71.19	NH4NO3	51.00	70.32	(NH4)2HPO4	1.20	1.00	H2O	9.06	A + B
6	CO(NH2)2	46.50	XXc	NH4NO3	52.08	XXc	(NH4)2HPO4	1.42	XXc	H2O	---	A + B
7	CO(NH2)2	48.80	XXc	NH4NO3	49.35	XXc	(NH4)2HPO4	1.85	XXc	H2O	---	B + C
8	CO(NH2)2	49.70	106.09	NH4NO3	41.30	66.14	(NH4)2HPO4	1.20	1.16	H2O	7.80	B + C
9	CO(NH2)2	53.41	48.25	NH4NO3	26.20	17.76	(NH4)2HPO4	1.96	0.805	H2O	18.43	B + C
10	CO(NH2)2	56.54	42.64	NH4NO3	19.32	10.93	(NH4)2HPO4	2.06	0.706	H2O	22.08	B + C
11	CO(NH2)2	60.96	37.72	NH4NO3	9.37	4.35	(NH4)2HPO4	2.76	0.777	H2O	26.91	B + C
12	CO(NH2)2	61.00	34.09	NH4NO3	5.61	2.35	(NH4)2HPO4	3.60	0.915	H2O	29.79	B + C
13	CO(NH2)2	62.77	35.54	NH4NO3	0.000	0.000	(NH4)2HPO4	7.82	2.01	H2O	29.41	B + C
14	CO(NH2)2	0.000	0.000	NH4NO3	77.05	41.94	(NH4)2HPO4	0.000	0.000	H2O	22.95	A
15	CO(NH2)2	66.52	33.08	NH4NO3	0.000	0.000	(NH4)2HPO4	0.000	0.000	H2O	33.48	C
16	CO(NH2)2	0.000	0.000	NH4NO3	0.000	0.000	(NH4)2HPO4	46.50	6.58	H2O	53.50	B

Part 2. The authors express the composition of the solutions in Part 1 in the following way also.

Solution number	Chemical1	Composition1(a)	Chemical2	Composition2	Chemical3	Composition3	Chemical4	Composition4
1	CO(NH2)2	---	NH4NO3	94.28	(NH4)2HPO4	5.72	H2O	38.45
2	CO(NH2)2	12.20	NH4NO3	84.21	(NH4)2HPO4	3.59	H2O	28.19
3	CO(NH2)2	20.55	NH4NO3	77.41	(NH4)2HPO4	2.04	H2O	23.61
4	CO(NH2)2	33.17	NH4NO3	65.20	(NH4)2HPO4	1.63	H2O	11.10
5	CO(NH2)2	42.80	NH4NO3	56.25	(NH4)2HPO4	0.94	H2O	9.90
6	CO(NH2)2	46.50	NH4NO3	52.08	(NH4)2HPO4	1.42	H2O	---
7	CO(NH2)2	48.80	NH4NO3	49.35	(NH4)2HPO4	1.85	H2O	---
8	CO(NH2)2	53.90	NH4NO3	44.80	(NH4)2HPO4	1.30	H2O	8.45
9	CO(NH2)2	65.45	NH4NO3	32.15	(NH4)2HPO4	2.40	H2O	22.60
10	CO(NH2)2	72.56	NH4NO3	24.80	(NH4)2HPO4	2.64	H2O	28.33
11	CO(NH2)2	83.40	NH4NO3	12.85	(NH4)2HPO4	3.75	H2O	36.83
12	CO(NH2)2	86.86	NH4NO3	8.00	(NH4)2HPO4	5.14	H2O	42.42
13	CO(NH2)2	88.91	NH4NO3	---	(NH4)2HPO4	11.09	H2O	41.66
14	CO(NH2)2	---	NH4NO3	100.00	(NH4)2HPO4	---	H2O	29.78
15	CO(NH2)2	100.00	NH4NO3	---	(NH4)2HPO4	---	H2O	50.33
16	CO(NH2)2	---	NH4NO3	---	(NH4)2HPO4	100.00	H2O	115.04

Notes:
   Table 1  ^a  The molalitiese were calculated by the compiler.
   Table 1  ^b  The solid phases are: A=NH₄NO₃; B=(NH₄)₂HPO₄; C=CO(NH₂)₂.
   Table 1  ^c  The molalities designated as XX cannot be calculated because the solutions are anhydrous.
   Table 2  ^a  The authors state that the composition unit is g H₂O/100 g solute. The compiler's opinion is that this is a typographical error and the composition unit is g/100 g solute.

Method/Apparatus/Procedure:
   An isothermal method was used. Equilibrium was checked by repeated analysis.

Source and Purity of Materials:
   No information is given.

Estimated Errors:
   Solubility: No information given.
   Temperature: The temperature was kept constant to within 0.1 K.

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Last updated: February 18, 2015 (Created: August 17, 2007)