IUPAC-NIST Solubility Database
NIST Standard Reference Database 106

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

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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:
   Uno, S., Kogyo Kagaku Zashi 1940, 43, 399; J. Soc. Chim. Ind., Japan, Suppl. Binding 1940, 43, 168B/70B.

Variables:

   Concentration = Composition at 0 ºC, 25 ºC, 40 ºC, 70 ºC and 100 ºC

Prepared By:
   Hiroshi Miyamoto and J. Eysseltová

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

Composition of saturated solutions in the (NH₄)₂SO₄-H₃PO₄-H₂O system.

Solution number	t/°C	Chemical1	102 * Mass Fraction w1	Chemical2	102 * Mass Fraction w2	Solid Phase(s)(a)
1	25	(NH4)2SO4	43.3	H3PO4	0.0	A
2	25	(NH4)2SO4	41.0	H3PO4	10.6	A
3	25	(NH4)2SO4	39.9	H3PO4	15.6	A
4	25	(NH4)2SO4	39.7	H3PO4	19.4	A + B
5	25	(NH4)2SO4	39.8	H3PO4	19.4	A + B
6	25	(NH4)2SO4	36.5	H3PO4	22.8	B
7	25	(NH4)2SO4	33.8	H3PO4	25.1	B
8	25	(NH4)2SO4	29.7	H3PO4	31.7	B
9	25	(NH4)2SO4	24.0	H3PO4	40.6	B
10	25	(NH4)2SO4	18.3	H3PO4	52.3	B
11	25	(NH4)2SO4	15.8	H3PO4	58.6	B
12	25	(NH4)2SO4	13.3	H3PO4	64.4	B
13	70	(NH4)2SO4	47.8	H3PO4	0.0	A
14	70	(NH4)2SO4	45.7	H3PO4	9.46	A
15	70	(NH4)2SO4	44.6	H3PO4	17.3	A
16	70	(NH4)2SO4	44.1	H3PO4	23.9	A
17	70	(NH4)2SO4	44.0	H3PO4	27.3	A
18	70	(NH4)2SO4	44.2	H3PO4	29.6	A + B
19	70	(NH4)2SO4	43.4	H3PO4	30.3	B
20	70	(NH4)2SO4	42.2	H3PO4	31.3	B
21	70	(NH4)2SO4	38.6	H3PO4	36.3	B
22	70	(NH4)2SO4	35.1	H3PO4	41.2	B
23	70	(NH4)2SO4	30.6	H3PO4	47.7	B
24	70	(NH4)2SO4	28.3	H3PO4	52.0	B
25	70	(NH4)2SO4	24.1	H3PO4	59.9	B

Composition of saturated solutions in the (NH₄)₂H₃(PO₄(SO₄)-(NH₄)₂SO₄-H₂O system.

Solution number	t/°C	Chemical1	Composition1 [g/100 g H2O](a)	Chemical2	Composition2 [g/100 g H2O](a)	Solid Phase(s)(b)
26	0	(NH4)2SO4	70.6	(NH4)2H3(PO4)(SO4)	0	A
27	0	(NH4)2SO4	60.8	(NH4)2H3(PO4)(SO4)	20.1	"
28	0	(NH4)2SO4	45.2	(NH4)2H3(PO4)(SO4)	51.9	"
29	0	(NH4)2SO4	36.1	(NH4)2H3(PO4)(SO4)	72.6	A + B
30	0	(NH4)2SO4	27.7	(NH4)2H3(PO4)(SO4)	80.1	B
31	0	(NH4)2SO4	10.9	(NH4)2H3(PO4)(SO4)	93.2	"
32	0	(NH4)2SO4	0	(NH4)2H3(PO4)(SO4)	107.9	"
33	25	(NH4)2SO4	76.2	(NH4)2H3(PO4)(SO4)	0	A
34	25	(NH4)2SO4	55.1	(NH4)2H3(PO4)(SO4)	51.4	"
35	25	(NH4)2SO4	37.2	(NH4)2H3(PO4)(SO4)	100.3	"
36	25	(NH4)2SO4	33.0	(NH4)2H3(PO4)(SO4)	111.7	A + B
37	25	(NH4)2SO4	33.3	(NH4)2H3(PO4)(SO4)	111.4	"
38	25	(NH4)2SO4	16.1	(NH4)2H3(PO4)(SO4)	125.2	B
39	25	(NH4)2SO4	0	(NH4)2H3(PO4)(SO4)	143.4	"
40	40	(NH4)2SO4	80.8	(NH4)2H3(PO4)(SO4)	0	A
41	40	(NH4)2SO4	60.6	(NH4)2H3(PO4)(SO4)	51.4	"
42	40	(NH4)2SO4	43.4	(NH4)2H3(PO4)(SO4)	104.6	"
43	40	(NH4)2SO4	27.6	(NH4)2H3(PO4)(SO4)	150.2	A + B
44	40	(NH4)2SO4	27.7	(NH4)2H3(PO4)(SO4)	149.3	"
45	40	(NH4)2SO4	13.4	(NH4)2H3(PO4)(SO4)	163.1	B
46	40	(NH4)2SO4	0	(NH4)2H3(PO4)(SO4)	176.0	"
47	70	(NH4)2SO4	91.4	(NH4)2H3(PO4)(SO4)	0	A
48	70	(NH4)2SO4	73.5	(NH4)2H3(PO4)(SO4)	49.6	"
49	70	(NH4)2SO4	55.8	(NH4)2H3(PO4)(SO4)	106.4	"
50	70	(NH4)2SO4	37.0	(NH4)2H3(PO4)(SO4)	175.4	"
51	70	(NH4)2SO4	24.9	(NH4)2H3(PO4)(SO4)	223.3	"
52	70	(NH4)2SO4	16.4	(NH4)2H3(PO4)(SO4)	265.8	A + B
53	70	(NH4)2SO4	9.44	(NH4)2H3(PO4)(SO4)	270.8	B
54	70	(NH4)2SO4	0	(NH4)2H3(PO4)(SO4)	277.5	"
55	100	(NH4)2SO4	103.6	(NH4)2H3(PO4)(SO4)	0	A
56	100	(NH4)2SO4	73.2	(NH4)2H3(PO4)(SO4)	105.3	"
57	100	(NH4)2SO4	43.2	(NH4)2H3(PO4)(SO4)	218.1	"
58	100	(NH4)2SO4	27.4	(NH4)2H3(PO4)(SO4)	296.9	"
59	100	(NH4)2SO4	17.6	(NH4)2H3(PO4)(SO4)	375.6	"
60	100	(NH4)2SO4	13.4	(NH4)2H3(PO4)(SO4)	441.0	"
61	100	(NH4)2SO4	11.2	(NH4)2H3(PO4)(SO4)	481.6	A + B
62	100	(NH4)2SO4	12.0	(NH4)2H3(PO4)(SO4)	480.2	"
63	100	(NH4)2SO4	5.27	(NH4)2H3(PO4)(SO4)	482.4	B
64	100	(NH4)2SO4	0	(NH4)2H3(PO4)(SO4)	490.0	"

Composition of saturated solutions in the (NH₄)₂H₃(PO₄)(SO₄)-NH₄H₂PO₄-H₃PO₄-H₂O system.

Solution number	t/°C	Chemical1	Composition1 [g/100g H2O](a)	Chemical2	Composition2 [g/100g H2O](a)	Chemical3	Composition3 [g/100g H2O](a)
65	25	NH4H2PO4	19.3	(NH4)2H3(PO4)(SO4)	132.7	H3PO4	0
66	25	NH4H2PO4	21.6	(NH4)2H3(PO4)(SO4)	113.9	H3PO4	8.31
67	25	NH4H2PO4	25.2	(NH4)2H3(PO4)(SO4)	79.2	H3PO4	23.3
68	25	NH4H2PO4	36.7	(NH4)2H3(PO4)(SO4)	58.1	H3PO4	33.0
69	25	NH4H2PO4	68.4	(NH4)2H3(PO4)(SO4)	37.1	H3PO4	53.7
70	70	NH4H2PO4	74.5	(NH4)2H3(PO4)(SO4)	234.6	H3PO4	0
71	70	NH4H2PO4	70.1	(NH4)2H3(PO4)(SO4)	217.9	H3PO4	3.65
72	70	NH4H2PO4	58.8	(NH4)2H3(PO4)(SO4)	177.1	H3PO4	22.1
73	70	NH4H2PO4	72.7	(NH4)2H3(PO4)(SO4)	123.2	H3PO4	44.1

Part 2. The compilers used the data in Part 1 to calculate 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	11.1	11.6	H3PO4	0.0	0.0	H2SO4	32.2	5.78	H2O	56.7
2	NH3	10.6	12.8	H3PO4	10.6	2.23	H2SO4	30.4	6.41	H2O	48.4
3	NH3	10.3	13.6	H3PO4	15.6	3.58	H2SO4	29.6	6.79	H2O	44.5
4	NH3	10.2	14.7	H3PO4	19.4	4.84	H2SO4	29.5	7.35	H2O	40.9
5	NH3	10.3	14.8	H3PO4	19.4	4.85	H2SO4	29.5	7.38	H2O	40.8
6	NH3	9.41	13.6	H3PO4	22.8	5.72	H2SO4	27.1	6.79	H2O	40.7
7	NH3	8.71	12.4	H3PO4	25.1	6.23	H2SO4	25.1	6.22	H2O	41.1
8	NH3	7.66	11.6	H3PO4	31.7	8.38	H2SO4	22.0	5.82	H2O	38.6
9	NH3	6.19	10.3	H3PO4	40.6	11.7	H2SO4	17.8	5.13	H2O	35.4
10	NH3	4.72	9.42	H3PO4	52.3	18.2	H2SO4	13.6	4.71	H2O	29.4
11	NH3	4.07	9.34	H3PO4	58.6	23.4	H2SO4	11.7	4.67	H2O	25.6
12	NH3	3.43	6.82	H3PO4	64.4	29.5	H2SO4	9.87	3.41	H2O	29.5
13	NH3	12.3	13.9	H3PO4	0.0	0.0	H2SO4	35.5	6.93	H2O	52.2
14	NH3	11.8	15.4	H3PO4	9.46	2.15	H2SO4	33.9	7.71	H2O	44.8
15	NH3	11.5	17.7	H3PO4	17.3	4.63	H2SO4	33.1	8.86	H2O	38.1
16	NH3	11.4	20.9	H3PO4	23.9	7.62	H2SO4	32.7	10.4	H2O	32.0
17	NH3	11.3	23.2	H3PO4	27.3	9.71	H2SO4	32.7	11.6	H2O	28.7
18	NH3	11.4	25.5	H3PO4	29.6	11.5	H2SO4	32.8	12.8	H2O	26.2
19	NH3	11.2	25.0	H3PO4	30.3	11.8	H2SO4	32.2	12.5	H2O	26.3
20	NH3	10.9	24.1	H3PO4	31.3	12.1	H2SO4	31.3	12.1	H2O	26.5
21	NH3	9.95	23.3	H3PO4	36.3	14.8	H2SO4	28.7	11.6	H2O	25.1
22	NH3	9.05	22.4	H3PO4	41.2	17.7	H2SO4	26.1	11.2	H2O	23.7
23	NH3	7.89	21.3	H3PO4	47.7	22.4	H2SO4	22.7	10.7	H2O	21.7
24	NH3	7.29	21.7	H3PO4	52.0	26.9	H2SO4	21.0	10.9	H2O	19.7
25	NH3	6.21	22.8	H3PO4	59.9	38.2	H2SO4	17.9	11.4	H2O	16.0
26	NH3	10.7	10.7	H3PO4	0.0	0.0	H2SO4	30.7	5.34	H2O	58.6
27	NH3	10.3	10.9	H3PO4	4.72	0.873	H2SO4	29.7	5.47	H2O	55.3
28	NH3	9.81	11.4	H3PO4	11.2	2.26	H2SO4	28.2	5.68	H2O	50.7
29	NH3	9.61	11.8	H3PO4	14.8	3.15	H2SO4	27.7	5.89	H2O	47.9
30	NH3	9.14	11.2	H3PO4	16.4	3.48	H2SO4	26.3	5.58	H2O	48.1
31	NH3	8.13	9.75	H3PO4	19.4	4.05	H2SO4	23.4	4.87	H2O	49.0
32	NH3	7.68	9.38	H3PO4	22.1	4.69	H2SO4	22.1	4.69	H2O	48.1
33	NH3	11.1	11.5	H3PO4	0.0	0.0	H2SO4	32.1	5.77	H2O	56.8
34	NH3	10.6	12.8	H3PO4	10.6	2.23	H2SO4	30.4	6.40	H2O	48.4
35	NH3	10.3	14.3	H3PO4	18.0	4.36	H2SO4	29.6	7.17	H2O	42.1
36	NH3	10.2	14.7	H3PO4	19.4	4.85	H2SO4	29.5	7.35	H2O	40.9
37	NH3	10.2	14.7	H3PO4	19.4	4.84	H2SO4	29.5	7.36	H2O	40.9
38	NH3	9.40	13.3	H3PO4	22.1	5.44	H2SO4	27.1	6.66	H2O	41.4
39	NH3	8.72	12.5	H3PO4	25.1	6.23	H2SO4	25.1	6.23	H2O	41.1
40	NH3	11.5	12.2	H3PO4	0.0	0.0	H2SO4	33.2	6.11	H2O	55.3
41	NH3	11.0	13.6	H3PO4	10.3	2.23	H2SO4	31.5	6.82	H2O	47.2
42	NH3	10.8	15.7	H3PO4	18.0	4.55	H2SO4	31.0	7.83	H2O	40.3
43	NH3	10.6	17.2	H3PO4	23.0	6.53	H2SO4	30.4	8.61	H2O	36.0
44	NH3	10.6	17.2	H3PO4	23.0	6.49	H2SO4	30.4	8.58	H2O	36.1
45	NH3	9.98	16.2	H3PO4	25.1	7.09	H2SO4	28.7	8.10	H2O	36.2
46	NH3	9.44	15.3	H3PO4	27.2	7.65	H2SO4	27.2	7.65	H2O	36.2
47	NH3	12.3	13.8	H3PO4	0.0	0.0	H2SO4	35.4	6.92	H2O	52.2
48	NH3	11.8	15.4	H3PO4	9.47	2.16	H2SO4	33.9	7.72	H2O	44.8
49	NH3	11.5	17.7	H3PO4	17.3	4.62	H2SO4	33.1	8.85	H2O	38.1
50	NH3	11.4	20.8	H3PO4	23.9	7.62	H2SO4	32.7	10.4	H2O	32.0
51	NH3	11.3	23.2	H3PO4	27.3	9.70	H2SO4	32.7	11.6	H2O	28.7
52	NH3	11.4	25.6	H3PO4	29.6	11.5	H2SO4	32.8	12.8	H2O	26.2
53	NH3	11.2	25.0	H3PO4	30.3	11.8	H2SO4	32.2	12.5	H2O	26.3
54	NH3	10.9	24.1	H3PO4	31.3	12.1	H2SO4	31.3	12.1	H2O	26.5
55	NH3	13.1	15.7	H3PO4	0.0	0.0	H2SO4	37.8	7.84	H2O	49.1
56	NH3	12.4	20.2	H3PO4	16.1	4.58	H2SO4	35.6	10.1	H2O	35.9
57	NH3	12.0	25.5	H3PO4	25.7	9.48	H2SO4	34.6	12.7	H2O	27.7
58	NH3	12.0	29.9	H3PO4	29.8	12.9	H2SO4	34.6	15.0	H2O	23.6
59	NH3	12.2	35.3	H3PO4	32.4	16.3	H2SO4	35.1	17.7	H2O	20.3
60	NH3	12.4	40.4	H3PO4	33.9	19.2	H2SO4	35.7	20.2	H2O	18.0
61	NH3	12.5	43.5	H3PO4	34.6	20.9	H2SO4	36.0	21.8	H2O	16.9
62	NH3	12.5	43.5	H3PO4	34.5	20.9	H2SO4	36.1	21.8	H2O	16.9
63	NH3	12.4	42.7	H3PO4	35.0	21.0	H2SO4	35.6	21.4	H2O	17.0
64	NH3	12.3	42.6	H3PO4	35.4	21.3	H2SO4	35.4	21.3	H2O	16.9
65	NH3	8.93	13.2	H3PO4	28.9	7.44	H2SO4	22.4	5.775	H2O	39.7
66	NH3	8.17	11.6	H3PO4	30.8	7.59	H2SO4	19.7	4.868	H2O	41.4
67	NH3	6.79	9.07	H3PO4	34.5	8.01	H2SO4	14.8	3.441	H2O	43.9
68	NH3	6.16	8.24	H3PO4	39.1	9.08	H2SO4	10.9	2.525	H2O	43.9
69	NH3	6.02	9.17	H3PO4	49.3	13.0	H2SO4	6.10	1.612	H2O	38.6
70	NH3	11.2	26.9	H3PO4	39.9	16.7	H2SO4	24.4	10.2	H2O	24.4
71	NH3	10.9	25.0	H3PO4	39.9	15.9	H2SO4	23.7	9.49	H2O	25.5
72	NH3	9.75	20.5	H3PO4	41.2	15.1	H2SO4	21.1	7.70	H2O	27.9
73	NH3	8.53	17.0	H3PO4	46.6	16.2	H2SO4	15.4	5.35	H2O	29.4

Notes:
   Table 1  ^a  The solid phases are: A=(NH₄)₂SO₄; B=(NH₄)₂H₃(PO₄)(SO₄).
   Table 2  ^a  The composition unit is: g/100g H₂O.
   Table 2  ^b  The solic phases are A=(NH₄)₂SO₄; B=(NH₄)₂H₃(PO₄)(SO₄).
   Table 3  ^a  The composition unit is: g/100g H₂O.

Method/Apparatus/Procedure:
   The isothermal method was used. Ammonium sulfate, phosphoric acid and water were placed in ampules. The mixtures were shaken in a thermostat at 25 °C and 70 °C. After equilibrium was established, the mixtures were allowed to settle. A pipet was used to obtain aliquots of the saturated solution for analysis. The saturated solution was evaporated to dryness and the solid obtained was dried at 110 °C to 115 °C to determine total solid content. The NH₃ content was determined by the distillation method. The phosphate and sulfate contents were determined gravimetrically as Mg(NH₄)PO₄ and BaSO₄, respectively.

Source and Purity of Materials:
   Chemically pure reagents were used. Ammonium sulfate was recrystallized.

Estimated Errors:
   Solubility: nothing specified.
   Temperature: precision ±0.05 K at 298 K and ±0.5 K at 343 K.

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