IUPAC-NIST Solubility Database
NIST Standard Reference Database 106

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 Solubility System: Ammonium dihydrogenphosphate with 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) Water; H2O; [7732-18-5]  NIST Chemistry WebBook for detail

Original Measurements:
   Fridman, S.D.; Polyakov, N.N.; Skum, L.S.; Kirindasova, R.Ya., Khim. Prom. (Moscow) 1967, 43, 206.

Variables:

   Concentration = Temperature and composition

Prepared By:
   J. Eysseltová

Experimental Remarks:

   Remarks: The temperature of disappearance of the last crystal is reported as a linear function of the water content of the saturated solution, Eq. [1]: t=a–h(100w₃)          [1] The values of the constants a and b depend on the NH₄H₂PO₄/NH₄NO₃ ratio only and are given in Table I. NOTE: The solubility isotherms were derived from the experimental data. NOTE: For all these solutions, NH₄H₂PO₄ was the equilibrium solid phase.

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

Table I. Values of the constants a and b in equation (1).

Chemical1	Comment(s)
Relation of NH<4>H<2>PO<4>/NH<4>NO<3> = 10:90	a= 155.0, b=2.08
20:80	a= 170.5, b=2.12
30:70	a= 176.0, b=2.12
42:58	a= 180.5, b=2.12
55:45	a= 182.5, b=2.12
70:30	a= 188.5, b=2.33
80:20	a= 191.5, b=2.45

Table II. Solubility in the NH₄H₂PO₄-NH₄NO₃-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
100	NH4H2PO4	7.4	2.46	NH4NO3	66.5	31.8	H2O	26.1
100	NH4H2PO4	13.4	3.52	NH4NO3	53.5	20.2	H2O	33.1
100	NH4H2PO4	19.2	4.64	NH4NO3	44.8	15.5	H2O	36.0
100	NH4H2PO4	43.5	9.98	NH4NO3	18.6	6.13	H2O	37.9
100	NH4H2PO4	50.4	11.8	NH4NO3	12.6	4.25	H2O	37.0
110	NH4H2PO4	7.9	3.22	NH4NO3	70.8	41.5	H2O	21.3
110	NH4H2PO4	14.3	4.38	NH4NO3	57.3	25.2	H2O	28.4
110	NH4H2PO4	20.7	5.79	NH4NO3	48.2	19.4	H2O	31.1
110	NH4H2PO4	28.0	7.31	NH4NO3	38.7	14.5	H2O	33.3
110	NH4H2PO4	36.2	9.23	NH4NO3	29.7	10.9	H2O	34.1
110	NH4H2PO4	46.5	12.0	NH4NO3	19.9	7.40	H2O	33.6
110	NH4H2PO4	53.6	14.1	NH4NO3	13.4	5.07	H2O	33.0
120	NH4H2PO4	8.3	4.37	NH4NO3	75.2	56.9	H2O	16.5
120	NH4H2PO4	15.3	5.64	NH4NO3	61.1	32.3	H2O	23.6
120	NH4H2PO4	22.0	7.22	NH4NO3	51.5	24.3	H2O	26.5
120	NH4H2PO4	30.0	9.15	NH4NO3	41.5	8.2	H2O	28.5
120	NH4H2PO4	38.8	11.5	NH4NO3	31.8	13.5	H2O	29.4
120	NH4H2PO4	49.4	14.6	NH4NO3	21.2	9.01	H2O	29.4
120	NH4H2PO4	56.8	17.0	NH4NO3	14.2	6.12	H2O	29.0
130	NH4H2PO4	8.8	6.5	NH4NO3	79.4	84.1	H2O	11.8
130	NH4H2PO4	16.2	7.41	NH4NO3	64.8	42.6	H2O	19.0
130	NH4H2PO4	23.5	9.37	NH4NO3	54.7	31.4	H2O	21.8
130	NH4H2PO4	32.0	11.6	NH4NO3	44.1	23.0	H2O	23.9
130	NH4H2PO4	41.5	14.7	NH4NO3	33.9	17.2	H2O	24.6
130	NH4H2PO4	52.4	18.2	NH4NO3	22.5	11.2	H2O	25.1
130	NH4H2PO4	60.08	20.97	NH4NO3	15.02	7.535	H2O	24.9
140	NH4H2PO4	9.3	11.5	NH4NO3	83.7	149.4	H2O	7.0
140	NH4H2PO4	17.2	10.5	NH4NO3	68.6	60.3	H2O	14.2
140	NH4H2PO4	24.9	12.7	NH4NO3	58.0	42.4	H2O	17.1
140	NH4H2PO4	33.9	15.3	NH4NO3	46.9	30.5	H2O	19.2
140	NH4H2PO4	44.0	19.1	NH4NO3	36.0	22.5	H2O	20.0
140	NH4H2PO4	55.5	23.3	NH4NO3	23.8	14.4	H2O	20.7
140	NH4H2PO4	63.4	26.5	NH4NO3	15.8	9.49	H2O	20.8
150	NH4H2PO4	9.8	38.7	NH4NO3	88.0	499.7	H2O	2.2
150	NH4H2PO4	18.1	16.6	NH4NO3	72.4	95.2	H2O	9.5
150	NH4H2PO4	26.3	18.4	NH4NO3	61.3	61.8	H2O	12.4
150	NH4H2PO4	35.9	21.5	NH4NO3	49.6	42.7	H2O	14.5
150	NH4H2PO4	46.6	26.5	NH4NO3	38.1	31.1	H2O	15.3
150	NH4H2PO4	59.9	36.2	NH4NO3	25.7	22.3	H2O	14.4
150	NH4H2PO4	66.6	34.5	NH4NO3	16.6	12.3	H2O	16.8
160	NH4H2PO4	19.0	34.4	NH4NO3	76.2	198.3	H2O	4.8
160	NH4H2PO4	27.7	30.9	NH4NO3	64.5	103.3	H2O	7.8
160	NH4H2PO4	37.9	33.6	NH4NO3	52.3	66.7	H2O	9.8
160	NH4H2PO4	49.1	39.9	NH4NO3	40.2	46.9	H2O	10.7
160	NH4H2PO4	61.5	43.8	NH4NO3	26.3	26.9	H2O	12.2
160	NH4H2PO4	69.8	47.4	NH4NO3	17.4	17.0	H2O	12.8
170	NH4H2PO4	20.0	869.3	NH4NO3	79.8	4984.5	H2O	0.2
170	NH4H2PO4	29.1	87.2	NH4NO3	68.0	292.9	H2O	2.9
170	NH4H2PO4	39.9	68.0	NH4NO3	55.0	134.7	H2O	5.1
170	NH4H2PO4	51.1	67.3	NH4NO3	42.3	80.1	H2O	6.6
170	NH4H2PO4	64.4	70.0	NH4NO3	27.6	43.1	H2O	8.0
170	NH4H2PO4	73.0	72.9	NH4NO3	18.3	26.3	H2O	8.7
180	NH4H2PO4	41.9	1214.1	NH4NO3	57.8	2406.8	H2O	0.3
180	NH4H2PO4	54.3	363.1	NH4NO3	44.4	426.7	H2O	1.3
180	NH4H2PO4	67.4	158.3	NH4NO3	28.9	97.6	H2O	3.7
180	NH4H2PO4	76.2	140.9	NH4NO3	19.1	50.8	H2O	4.7

Notes:
   Table 1  ^a  The molalities were calculated by the compiler.

Method/Apparatus/Procedure:
   A visual polythermic method was used.

Source and Purity of Materials:
   No information is given.

Estimated Errors:
   Solubility: No information is given.
   Temperature: The precision of the temperature of disappearance of the last crystal was ± 0.5 K.

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