IUPAC-NIST Solubility Database
NIST Standard Reference Database 106

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 Solubility System: Ammonium dihydrogenphosphate with Urea, Ammonium nitrate and Water

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Components:
   (1) Ammonium dihydrogenphosphate; NH4H2PO4; [7722-76-1]  NIST Chemistry WebBook for detail
   (2) Ammonium nitrate; NH4NO3; [6484-52-2]  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 NH₄H₂PO₄-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	----	----	NH4NO3	71.77	34.32	NH4H2PO4	2.11	0.702	H2O	26.12	A + B
2	CO(NH2)2	13.90	11.66	NH4NO3	64.00	40.28	NH4H2PO4	2.25	0.985	H2O	19.85	A + B
3	CO(NH2)2	22.05	26.49	NH4NO3	61.89	55.78	NH4H2PO4	2.20	1.38	H2O	13.86	A + B
4	CO(NH2)2	32.06	47.53	NH4NO3	54.69	60.84	NH4H2PO4	2.02	1.56	H2O	11.23	A + B
5	CO(NH2)2	34.63	54.04	NH4NO3	53.25	62.34	NH4H2PO4	1.45	1.18	H2O	10.67	A + B
6	CO(NH2)2	46.50	XX (c)	NH4NO3	51.66	XX (c)	NH4H2PO4	1.84	XX (c)	H2O	---	A + B
7	CO(NH2)2	48.92	XX (c)	NH4NO3	48.58	XX (c)	NH4H2PO4	2.51	XX (c)	H2O	---	B + C
8	CO(NH2)2	51.40	56.56	NH4NO3	30.97	25.57	NH4H2PO4	2.50	1.44	H2O	15.13	B + C
9	CO(NH2)2	52.62	59.89	NH4NO3	30.00	25.62	NH4H2PO4	2.75	1.63	H2O	14.63	B + C
10	CO(NH2)2	52.95	38.12	NH4NO3	16.44	8.88	NH4H2PO4	7.48	2.81	H2O	23.13	B + C
11	CO(NH2)2	53.30	33.91	NH4NO3	8.25	3.94	NH4H2PO4	12.28	4.08	H2O	26.17	B + C
12	CO(NH2)2	51.30	30.80	NH4NO3	----	----	NH4H2PO4	20.97	6.57	H2O	27.73	B + C
13	CO(NH2)2	----	----	NH4NO3	77.05	41.94	NH4H2PO4	----	----	H2O	22.95	A
14	CO(NH2)2	66.52	33.08	NH4NO3	----	----	NH4H2PO4	----	----	H2O	33.48	C
15	CO(NH2)2	----	----	NH4NO3	----	----	NH4H2PO4	41.60	6.19	H2O	58.40	B

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

Solution number	Chemical1	Composition1(a)	Chemical2	Composition2(a)	Chemical3	Composition3(a)	Chemical4	Composition4(a)
1	CO(NH2)2	97.10 (b)	NH4NO3	----	NH4H2PO4	2.9	H2O	35.40
2	CO(NH2)2	17.40	NH4NO3	79.79	NH4H2PO4	2.81	H2O	24.75
3	CO(NH2)2	25.50	NH4NO3	71.95	NH4H2PO4	2.55	H2O	16.10
4	CO(NH2)2	36.12	NH4NO3	61.69	NH4H2PO4	2.19	H2O	12.65
5	CO(NH2)2	38.78	NH4NO3	59.60	NH4H2PO4	1.62	H2O	11.96
6	CO(NH2)2	46.50	NH4NO3	51.66	NH4H2PO4	1.84	H2O	----
7	CO(NH2)2	48.92	NH4NO3	48.58	NH4H2PO4	2.51	H2O	----
8	CO(NH2)2	60.50	NH4NO3	36.55	NH4H2PO4	2.95	H2O	17.85
9	CO(NH2)2	61.60	NH4NO3	35.18	NH4H2PO4	3.22	H2O	17.20
10	CO(NH2)2	69.60	NH4NO3	21.40	NH4H2PO4	9.00	H2O	30.13
11	CO(NH2)2	77.20	NH4NO3	11.18	NH4H2PO4	16.62	H2O	35.60
12	CO(NH2)2	71.03	NH4NO3	----	NH4H2PO4	25.57	H2O	38.63
13	CO(NH2)2	----	NH4NO3	100.0	NH4H2PO4	----	H2O	29.78
14	CO(NH2)2	100.0	NH4NO3	----	NH4H2PO4	----	H2O	50.33
15	CO(NH2)2	----	NH4NO3	----	NH4H2PO4	100.0	H2O	140.60

Notes:
   Table 1  ^a  The compiler calculated the molalities as mol/kg H₂O values.
   Table 1  ^b  The solid phases are: A=NHNO₃; B=NH₄H₂PO₄; 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.
   Table 2  ^b  This is an obvious error. The correct values are: ---- for urea and 97.10 for NH₄NO₃ (compiler).

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 is 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)