IUPAC-NIST Solubilities Database

IUPAC-NIST Solubility Database
NIST Standard Reference Database 106

Solubility System: Ammonia with Phosphoric acid, Sulfuric acid and Water

Components:
   (1) Ammonia; NH3; [7664-41-7]  NIST Chemistry WebBook for detail
   (2) Phosphoric acid; H3PO4; [7664-38-2]  NIST Chemistry WebBook for detail
   (3) Sulfuric acid; H2SO4; [7664-93-9]  NIST Chemistry WebBook for detail
   (4) Water; H2O; [7732-18-5]  NIST Chemistry WebBook for detail

Original Measurements:
   Kaganskiy, I.M.; Babenko, A.M., Zh. Prikl. Khim. (Leningrad) 1975, 48, 1387.

Variables:

   Concentration = Concentration of (NH₄)₂SO₄ at 0 ºC and –10 ºC in an equimolar mixture of NH₄H₂PO₄ and (NH₄)₂HPO₄.

Prepared By:
   J. Eysseltová

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

Solubility isotherms in the NH₄H₂PO₄-(NH₄)₂HPO₄-(NH₄)₂SO₄-H₂O system.
Solution number	t/°C	Chemical₁	10² * Mass Fraction w₁	Chemical₂	10² * Mass Fraction w₂	Chemical₃	10² * Mass Fraction w₃	Chemical₄	10² * Mass Fraction w₄	Chemical₅	10² * Mass Fraction w₅	Chemical₆	10² * Mass Fraction w₆	Mass Ratio^(a)
1	-10	"Mixture" (a)	14.706	NH4H2PO4	6.8945	(NH4)2HPO4	7.9152	(NH4)2SO4	18.3	H2O	66.94	(N + P2O5)	19.25	0.75:1:0.52 (N:P2O5:S)
2	-10	"Mixture" (a)	11.6	NH4H2PO4	5.44	(NH4)2HPO4	6.24	(NH4)2SO4	26.52	H2O	61.88	(N + P2O5)	20.6	1.14:1:0.96
3	-10	"Mixture" (a)	19.481	NH4H2PO4	9.1331	(NH4)2HPO4	10.485	(NH4)2SO4	15.3	H2O	65.219	(N + P2O5)	21.44	0.58:1:0.32
4	-10	"Mixture" (a)	21.5	NH4H2PO4	10.1	(NH4)2HPO4	11.6	(NH4)2SO4	14.0	H2O	64.5	(N + P2O5)	22.35	0.55:1:0.28
5	-10	"Mixture" (a)	24.752	NH4H2PO4	11.604	(NH4)2HPO4	13.322	(NH4)2SO4	11.6	H2O	63.648	(N + P2O5)	23.68	0.47:1:0.20
6	-10	"Mixture" (a)	13.76	NH4H2PO4	6.451	(NH4)2HPO4	7.4060	(NH4)2SO4	31.2	H2O	55.04	(N + P2O5)	24.4	1.14:1:0.97
7	-10	"Mixture" (a)	19.4	NH4H2PO4	9.10	(NH4)2HPO4	10.4	(NH4)2SO4	22.4	H2O	58.2	(N + P2O5)	24.6	0.71:1:0.48
8	-10	"Mixture" (a)	31.02	NH4H2PO4	14.54	(NH4)2HPO4	16.70	(NH4)2SO4	6.0	H2O	62.98	(N + P2O5)	25.8	0.37:1:0.081
9	-10	"Mixture" (a)	15.91b	NH4H2PO4	7.459	(NH4)2HPO4	8.563	(NH4)2SO4	30.8	H2O	53.284	(N + P2O5)	25.8	1.0:1:0.81
10	-10	"Mixture" (a)	30.6b	NH4H2PO4	14.3	(NH4)2HPO4	16.5	(NH4)2SO4	7.2	H2O	62.176	(N + P2O5)	26.0	0.38:1:0.099
11	-10	"Mixture" (a)	24.42	NH4H2PO4	11.45	(NH4)2HPO4	13.14	(NH4)2SO4	18.6	H2O	56.98	(N + P2O5)	26.6	0.58:1:0.32
12	0	"Mixture" (a)	21.8	NH4H2PO4	10.2	(NH4)2HPO4	11.7	(NH4)2SO4	15.64	H2O	62.56	(N + P2O5)	23.32	0.56:1:0.30
13	0	"Mixture" (a)	16.4	NH4H2PO4	7.69	(NH4)2HPO4	8.83	(NH4)2SO4	25.08	H2O	58.52	(N + P2O5)	23.58	0.86:1:0.63
14	0	"Mixture" (a)	11.916	NH4H2PO4	5.5865	(NH4)2HPO4	6.4135	(NH4)2SO4	33.8	H2O	54.284	(N + P2O5)	24.24	1.33:1:1.18
15	0	"Mixture" (a)	13.52	NH4H2PO4	6.338	(NH4)2HPO4	7.277	(NH4)2SO4	32.4	H2O	54.08	(N + P2O5)	24.74	1.19:1:0.34
16	0	"Mixture" (a)	22.68	NH4H2PO4	10.63	(NH4)2HPO4	12.21	(NH4)2SO4	19.0	H2O	58.32	(N + P2O5)	25.5	0.59:1:0.34
17	0	"Mixture" (a)	15.732b	NH4H2PO4	7.3755	(NH4)2HPO4	8.4674	(NH4)2SO4	31.6	H2O	52.68	(N + P2O5)	26.0	1.04:1:0.85
18	0	"Mixture" (a)	24.18	NH4H2PO4	11.34	(NH4)2HPO4	13.01	(NH4)2SO4	19.4	H2O	56.42	(N + P2O5)	26.8	0.59:1:0.33
19	0	"Mixture" (a)	29.106b	NH4H2PO4	13.646	(NH4)2HPO4	15.666	(NH4)2SO4	11.8	H2O	59.09	(N + P2O5)	27.0	0.45:1:0.17
20	0	"Mixture" (a)	33.075	NH4H2PO4	15.506	(NH4)2HPO4	17.802	(NH4)2SO4	5.5	H2O	61.425	(N + P2O5)	27.0	0.35:1:0.06
21	0	"Mixture" (a)	41.832	NH4H2PO4	19.612	(NH4)2HPO4	22.515	(NH4)2SO4	0.4	H2O	57.768	(N + P2O5)	31.3	0.30:1:0.003

Part 2. The compiler has used the authors’ data (Part 1) to calculated the following values.
Solution number	Chemical₁	10² * Mass Fraction w₁	m₁ [mol/kg]	Chemical₂	10² * Mass Fraction w₂	m₂ [mol/kg]	Chemical₃	10² * Mass Fraction w₃	m₃ [mol/kg]	Chemical₄	10² * Mass Fraction w₄
1	NH3	7.757	6.799	H3PO4	11.66	1.776	H2SO4	13.58	2.067	H2O	67.00
2	NH3	9.233	8.761	H3PO4	9.200	1.517	H2SO4	19.68	3.243	H2O	61.88
3	NH3	7.971	7.176	H3PO4	15.45	2.417	H2SO4	11.36	1.775	H2O	65.22
4	NH3	8.053	7.331	H3PO4	17.05	2.698	H2SO4	10.39	1.642	H2O	64.50
5	NH3	8.107	7.479	H3PO4	19.63	3.147	H2SO4	8.609	1.379	H2O	63.65
6	NH3	10.89	11.61	H3PO4	10.91	2.023	H2SO4	23.16	4.289	H2O	55.04
7	NH3	9.784	9.871	H3PO4	16.39	2.698	H2SO4	16.62	2.912	H2O	58.20
8	NH3	7.960	7.421	H3PO4	24.60	3.986	H2SO4	4.453	0.721	H2O	62.98
9	NH3	11.23	12.37	H3PO4	12.62	2.416	H2SO4	22.86	4.373	H2O	53.29
10	NH3	8.182	7.724	H3PO4	24.27	3.981	H2SO4	5.344	0.876	H2O	62.20
11	NH3	9.843	10.14	H3PO4	19.37	3.468	H2SO4	13.81	2.470	H2O	56.98
12	NH3	8.538	8.013	H3PO4	17.29	2.820	H2SO4	11.61	1.892	H2O	62.56
13	NH3	9.855	9.888	H3PO4	13.01	2.268	H2SO4	18.61	3.243	H2O	58.52
14	NH3	11.18	12.09	H3PO4	9.451	1.776	H2SO4	25.09	4.711	H2O	54.29
15	NH3	11.15	12.10	H3PO4	10.72	2.023	H2SO4	24.05	4.533	H2O	54.08
16	NH3	9.586	9.651	H3PO4	17.99	3.147	H2SO4	14.10	2.465	H2O	58.32
17	NH3	11.40	12.71	H3PO4	12.48	2.417	H2SO4	23.45	4.540	H2O	52.67
18	NH3	9.999	10.41	H3PO4	19.18	3.468	H2SO4	14.40	2.602	H2O	56.42
19	NH3	9.059	9.001	H3PO4	23.09	3.986	H2SO4	8.758	1.511	H2O	59.10
20	NH3	8.256	7.891	H3PO4	26.23	4.358	H2SO4	4.082	0.678	H2O	61.43
21	NH3	8.752	8.895	H3PO4	33.18	5.860	H2SO4	0.29	0.052	H2O	57.77

Notes:
   Table 1  ^a  "Mixture" is an equimolar mixture of NH₄H₂PO₄ and (NH₄)₂HPO₄.
   Table 1  ^b  There is a typographical error on this line. The sum of the components does not equal 100.

Method/Apparatus/Procedure:
   An improved polythermic method was used.¹

Source and Purity of Materials:
   Chemically pure or reagent grade salts were used. They were recrystallized twice and dried at 40 °C to 50 °C.The material designated "mixture" was prepared by grinding an equimolar mixture of NH₄H₂PO₄ and (NH₄)₂HPO₄ in a mortar.

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

References:
   ¹Erayzer, L.N.; Kaganskiy, I.M. Zavod. Lab. 1967, 1, 119.