IUPAC-NIST Solubility Database
NIST Standard Reference Database 106

---

 Solubility System: Ammonium dihydrogenphosphate with Ammonium nitrate and Water

---

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:
   Bochkarev, P.F., Tr. Vostoch.-Sibir. Gosud. Inst. 3 (1935); Bergman, A.G.; Bochkarev, P.F., Zh. Prikl. Khim. (Leningrad) 10, 1531 (1937); Bergman, A.G.; Bochkarev, P.F., Izv. Akad. Nauk SSSR, Otd. Mat. Estestv. Nauk 237 (1938).

Variables:

   Concentration = Temperature and composition

Prepared By:
   L. V. Chernykh and J. Eysseltová

Experimental Remarks:

   Remarks: NOTE: These data are given in source paper (1) and repeated in source papers (2) and (3). The differences are due to typographical errors. In addition to the above data, source paper (3) also contains the following information about the composition and crystallization temperature of solutions saturated with two or three solid phases.

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

Solubility in the NH₄NO₃-NH₄H₂PO₄-H₂O system.

t/°C	Chemical1	Composition1(a)	102 * Mass Fraction w1	m1 [mol/kg](b)	Chemical2	Composition2(a)	102 * Mass Fraction w2	m2 [mol/kg](b)	Chemical3	Composition3(a)	102 * Mass Fraction w3	Solid Phase(s)(c)
-10	NH4NO3	100	27.2	4.7	NH4H2PO4	0	0.0	0.0	H2O	1188.5	72.8	A
-10	NH4NO3	85.1	22.0	3.8	NH4H2PO4	14.9	5.5	0.7	H2O	1245.8	72.5	A + B
-10	NH4NO3	91.6	28.8	5.3	NH4H2PO4	8.4	3.8	0.5	H2O	951.9	67.4	B
-10	NH4NO3	95.9	38.9	8.3	NH4H2PO4	4.1	2.4	0.4	H2O	642.6	58.7	B
-10	NH4NO3	97.1	45.0	10.6	NH4H2PO4	2.9	2	0.3	H2O	507.2	53	B
-10	NH4NO3	97.3	45.6	10.8	NH4H2PO4	2.7	1.8	0.3	H2O	498.3	52.6	B + C
-10	NH4NO3	100	47.0	11.1	NH4H2PO4	0	0.0	0.0	H2O	501.2	53.0	C
0	NH4NO3	0	0.0	0.0	NH4H2PO4	100	18.4	2.0	H2O	1830.6	81.6	B
0	NH4NO3	50.5	8.8	1.4	NH4H2PO4	49.5	12.4	1.4	H2O	1986.4	78.8	B
0	NH4NO3	76.3	18.3	3.1	NH4H2PO4	23.7	8.2	1.0	H2O	2360	73.5	B
0	NH4NO3	89.5	28.6	5.4	NH4H2PO4	10.5	4.8	0.6	H2O	926.6	66.6	B
0	NH4NO3	94.7	38.7	8.3	NH4H2PO4	5.3	3.1	0.5	H2O	633.6	58.2	B
0	NH4NO3	96.4	44.9	10.6	NH4H2PO4	3.6	2.4	0.4	H2O	502.6	52.7	B
0	NH4NO3	97.5	49.0	12.5	NH4H2PO4	2.5	1.9	0.3	H2O	433.9	49.1	B
0	NH4NO3	98.0	51.2	13.5	NH4H2PO4	2.0	1.5	0.3	H2O	402.0	47.3	B + C
0	NH4NO3	100	53.6	14.4	NH4H2PO4	0	0.0	0.0	H2O	384.5	46.4	C
10	NH4NO3	0.0	0.0	0.0	NH4H2PO4	100	21.4	2.4	H2O	2345.7	78.6	B
10	NH4NO3	43.75	8.4	1.4	NH4H2PO4	56.25	15.5	1.8	H2O	1760	76.1	B
10	NH4NO3	72.1	18.0	3.1	NH4H2PO4	27.9	10	1.2	H2O	1280	72	B
10	NH4NO3	81.4	23.5	4.3	NH4H2PO4	18.6	7.7	1.0	H2O	1057.9	68.8	B
10	NH4NO3	86.7	28.1	5.3	NH4H2PO4	13.3	6.2	0.8	H2O	890.9	65.7	B
10	NH4NO3	93.0	38.2	8.3	NH4H2PO4	7.0	4.1	0.6	H2O	624.4	57.7	B
10	NH4NO3	95.5	44.6	10.6	NH4H2PO4	4.5	3	0.5	H2O	498.8	52.4	B
10	NH4NO3	97.0	48.8	12.4	NH4H2PO4	3	2.2	0.4	H2O	432.4	49	B
10	NH4NO3	98.0	54.1	15.3	NH4H2PO4	2.0	1.6	0.3	H2O	356.4	44.3	B
10	NH4NO3	98.6	58.0	17.8	NH4H2PO4	1.4	1.2	0.3	H2O	308.2	40.8	B + C
10	NH4NO3	100	59.6	18.4	NH4H2PO4	0	0.0	0.0	H2O	301.6	40.4	C
20	NH4NO3	0	0.0	0.0	NH4H2PO4	100	25.5	3.0	H2O	1862.7	74.5	B
20	NH4NO3	38.3	8.1	1.4	NH4H2PO4	61.7	18.8	2.2	H2O	1536.7	73.1	B
20	NH4NO3	67.4	17.5	3.1	NH4H2PO4	32.6	12.2	1.5	H2O	1200.6	70.3	B
20	NH4NO3	83.1	27.6	5.4	NH4H2PO4	16.9	8.1	1.1	H2O	860.0	64.3	B
20	NH4NO3	86.2	30.5	6.1	NH4H2PO4	13.3	7	1.0	H2O	733.1	62.5	B
20	NH4NO3	91.5	37.9	8.3	NH4H2PO4	8.5	5.1	0.8	H2O	612	57	B
20	NH4NO3	94.5	44.3	10.6	NH4H2PO4	5.5	3.7	0.6	H2O	493.3	52	B
20	NH4NO3	96.2	48.6	12.5	NH4H2PO4	3.5	2.8	0.5	H2O	427.6	48.6	B
20	NH4NO3	97.2	53.8	15.3	NH4H2PO4	2.8	2.2	0.4	H2O	353.4	44	B
20	NH4NO3	98.1	59.0	18.7	NH4H2PO4	1.9	1.6	0.4	H2O	291.2	39.4	B
20	NH4NO3	98.8	64.0	23.0	NH4H2PO4	1.2	1.2	0.3	H2O	238.8	34.8	B + C
20	NH4NO3	100	65.1	23.3	NH4H2PO4	0	0.0	0.0	H2O	238.3	34.9	C
30	NH4NO3	0	0.0	0.0	NH4H2PO4	100	30.2	3.8	H2O	1478.6	69.8	B
30	NH4NO3	33.0	7.8	1.4	NH4H2PO4	67	22.7	2.8	H2O	1312.2	69.5	B
30	NH4NO3	61.7	16.9	3.1	NH4H2PO4	38.3	1.51	1.9	H2O	1103.5	68.0	B
30	NH4NO3	79.1	26.9	5.4	NH4H2PO4	20.9	10.3	1.4	H2O	820.2	62.8	B
30	NH4NO3	89.7	37.5	8.3	NH4H2PO4	10.3	6.2	1.0	H2O	598.7	56.3	B
30	NH4NO3	93.4	43.9	10.6	NH4H2PO4	6.6	4.5	0.8	H2O	487.9	51.6	B
30	NH4NO3	95.2	48.2	13.9	NH4H2PO4	4.8	8.5 (d)	0.6	H2O	424.2	43.5 (d)	B
30	NH4NO3	96.7	53.5	15.3	NH4H2PO4	3.3	2.7	0.5	H2O	351.8	43.8	B
30	NH4NO3	97.7	58.8	18.7	NH4H2PO4	2.3	2	0.4	H2O	289.7	39.2	B
30	NH4NO3	98.8	68.7	28.5	NH4H2PO4	1.2	1.2	0.3	H2O	192.5	30.1	B + C
30	NH4NO3	100	69.7	28.7	NH4H2PO4	0	0.0	0.0	H2O	193.1	30.3	C

Table 2. In addition to the above data, source paper (3) also contains the following information about the composition and crystallization temperature of solutions saturated with two or three solid phases.

t/°C	Chemical1	Composition1(a)	102 * Mass Fraction w1	m1 [mol/kg](b)	Chemical2	Composition2(a)	102 * Mass Fraction w2	m2 [mol/kg](b)	Chemical3	Composition3(a)	102 * Mass Fraction w3	Solid Phase(s)(c)
-4.4	NH4NO3	0	0	0	NH4H2PO4	100	17.4	1.83	H2O	3036.4	82.6	A + B
-4.6	NH4NO3	21.8	2.7	0.41	NH4H2PO4	78.2	14.1	1.47	H2O	2960.3	83.2	A +B
-6.3	NH4NO3	55.4	9	1	NH4H2PO4	44.6	10.4	1.12	H2O	2214.9	80.6	A + B
-6.9	NH4NO3	66.4	12	1.9	NH4H2PO4	33.6	8.8	0.97	H2O	1945.1	79.2	A + B
-9.0	NH4NO3	80.3	18.6	3.11	NH4H2PO4	13.7	6.6	0.77	H2O	1436.7	74.8	A + B
-12.9	NH4NO3	92.1	29.0	5.37	NH4H2PO4	7.9	3.6	0.46	H2O	951.9	67.4	A + B
-15.9	NH4NO3	96.3	39.1	8.42	NH4H2PO4	8.7 (d)	2.2	0.32	H2O	642.6	58.7	A + B
-11	NH4NO3	97.2	45.2	10.7	NH4H2PO4	2.8	1.8	0.30	H2O	506.4	53	B + C
-3.2	NH4NO3	97.8	49.2	12.5	NH4H2PO4	2.2	1.6	0.28	H2O	439.4	49.2	B + C
5.2	NH4NO3	98.4	54.2	15.2	NH4H2PO4	1.6	1.3	0.25	H2O	359.1	44.5	B + C
11.4	NH4NO3	98.5	59.3	18.8	NH4H2PO4	1.5	1.3	0.29	H2O	290.8	39.4	B + C
-16.4	NH4NO3	100	42.7	9.31	NH4H2PO4	0	0	0	H2O	596.8	57.3	A + C
-16.3	NH4NO3	98.3	41.1	8.87	NH4H2PO4	1.7	1.0	0.15	H2O	615.7	57.9	A + C
-16.8	NH4NO3	96.5	40.3	8.74	NH4H2PO4	3.5	2.1	0.32	H2O	613.6	57.6	A + B + C

Notes:
   Table 1  ^a  The composition unit is mol/100 mol solute.
   Table 1  ^b  The molalities were calculated by the compilers.
   Table 1  ^c  The solid phases are A=ice: B=NH₄H₂PO₄; C=NH₄NO₃.
   Table 1  ^d  The compilers believe these are erroneous, the proper values being 3.5 and 48.3 respectively.
   Table 2  ^a  The composition unit is mol/100 mol solute.
   Table 2  ^b  The molalities were calculated by the compilers.
   Table 2  ^c  The solid phases are: A=ice: B=NH₄H₂PO₄; C=NH₄NO₃
   Table 2  ^d  This is an obvious error. The compilers calculations are based on the 100w_i values.

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

Source and Purity of Materials:
   Chemically pure materials were recrystallized before use.

Estimated Errors:
   Solubility: No information is given.
   Temperature: No information is given.

---

Distributed by the Office of Data and Informatics of the National Institute of Standards and Technology (NIST) Material Measurement Laboratory (MML).
Website is owned by NIST (an agency of the U.S. Department of Commerce)

---

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