IUPAC-NIST Solubilities Database

IUPAC-NIST Solubility Database
NIST Standard Reference Database 106

Solubility System: Ammonia with Phosphoric acid, Calcium oxide and Water

Components:
   (1) Ammonia; NH3; [7664-41-7]  NIST Chemistry WebBook for detail
   (2) Calcium oxide; CaO; [1305-78-8]  NIST Chemistry WebBook for detail
   (3) Phosphoric acid; H3PO4; [7664-38-2]  NIST Chemistry WebBook for detail
   (4) Water; H2O; [7732-18-5]  NIST Chemistry WebBook for detail

Original Measurements:
   Orekhov, I.I.; Slobodkina, G.I., Zh. Neorg. Khim. 1972, 17, 829.

Variables:

   Concentration = Temperature and composition at a NH₃:H₃PO₄ ratio = 0.5

Prepared By:
   J. Eysseltová

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

Part 1. Solubility in the (NH₄)₃PO₄-H₃PO₄-Ca₃(PO₄)₂-H₂O system with the ratio NH₃/H₃PO₄ = 0.5.
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^(b)	Solid Phase(s)^(c)
1	45	CaO	1.33	NH3	1.24	P2O5	9.88	H2O	87.55	H3PO4	13.6	H2O	83.79	A
2	45	CaO	1.62	NH3	1.80	P2O5	14.77	H2O	81.81	H3PO4	20.40	H2O	76.18	“
3	45	CaO	1.84	NH3	2.41	P2O5	19.64	H2O	76.11	H3PO4	27.12	H2O	68.63	“
4	45	CaO	2.10	NH3	3.01	P2O5	24.56	H2O	70.33	H3PO4	33.91	H2O	60.98	“
5	45	CaO	2.32	NH3	3.68	P2O5	29.35	H2O	64.65	H3PO4	40.53	H2O	53.47	A + B
6	45	CaO	2.49	NH3	4.21	P2O5	34.13	H2O	59.17	H3PO4	47.13	H2O	46.17	A + B + C
7	45	CaO	2.44	NH3	4.79	P2O5	39.06	H2O	53.71	H3PO4	53.94	H2O	38.83	B + C
8	45	CaO	1.91	NH3	5.47	P2O5	44.22	H2O	48.40	H3PO4	61.06	H2O	31.56	“
9	45	CaO	1.17	NH3	6.06	P2O5	49.35	H2O	43.42	H3PO4	68.15	H2O	24.62	“
10	45	CaO	0.50	NH3	6.73	P2O5	54.72	H2O	38.05	H3PO4	75.56	H2O	17.21	“
11	60	CaO	0.89	NH3	1.26	P2O5	9.91	H2O	87.96	H3PO4	13.7	H2O	84.19	A
12	60	CaO	1.26	NH3	1.82	P2O5	14.81	H2O	82.11	H3PO4	20.45	H2O	76.47	"
13	60	CaO	1.57	NH3	2.41	P2O5	19.69	H2O	76.33	H3PO4	27.19	H2O	68.83	"
14	60	CaO	1.75	NH3	3.03	P2O5	24.56	H2O	70.66	H3PO4	33.91	H2O	61.31	"
15	60	CaO	2.07	NH3	3.62	P2O5	29.38	H2O	64.93	H3PO4	40.57	H2O	53.74	A + B
16	60	CaO	2.30	NH3	4.21	P2O5	34.20	H2O	59.29	H3PO4	47.23	H2O	46.26	"
17	60	CaO	2.52	NH3	4.79	P2O5	37.04	H2O	55.65	H3PO4	51.15	H2O	41.54	"
18	60	CaO	2.39	NH3	5.45	P2O5	43.92	H2O	48.24	H3PO4	60.65	H2O	31.51	A + B + C
19	60	CaO	1.61	NH3	6.05	P2O5	49.19	H2O	43.15	H3PO4	67.92	H2O	24.42	B + C
20	60	CaO	0.83	NH3	6.71	P2O5	54.54	H2O	37.92	H3PO4	75.31	H2O	17.15	"
21	75	CaO	0.68	NH3	1.24	P2O5	9.93	H2O	88.15	H3PO4	13.7	H2O	84.37	A + B
22	75	CaO	0.99	NH3	1.82	P2O5	14.86	H2O	82.33	H3PO4	20.52	H2O	76.67	"
23	75	CaO	1.24	NH3	2.41	P2O5	19.75	H2O	76.60	H3PO4	27.27	H2O	69.08	"
24	75	CaO	1.38	NH3	3.03	P2O5	24.69	H2O	70.90	H3PO4	34.09	H2O	61.50	"
25	75	CaO	1.81	NH3	3.53	P2O5	29.45	H2O	65.21	H3PO4	40.67	H2O	53.99	"
26	75	CaO	2.01	NH3	4.22	P2O5	34.30	H2O	59.47	H3PO4	47.36	H2O	46.41	"
27	75	CaO	.2.07	NH3	4.92	P2O5	39.17	H2O	53.84	H3PO4	54.09	H2O	38.92	"
28	75	CaO	2.43	NH3	5.44	P2O5	43.87	H2O	48.26	H3PO4	60.58	H2O	31.55	"
29	75	CaO	2.09	NH3	6.02	P2O5	49.68	H2O	42.21	H3PO4	68.60	H2O	23.29	B + C
30	75	CaO	1.36	NH3	6.67	P2O5	54.25	H2O	37.72	H3PO4	74.91	H2O	17.06	"
31	90	CaO	0.55	NH3	1.24	P2O5	9.94	H2O	88.27	H3PO4	13.7	H2O	84.48	A + B
32	90	CaO	0.80	NH3	1.83	P2O5	14.88	H2O	82.49	H3PO4	20.55	H2O	76.82	"
33	90	CaO	1.04	NH3	2.42	P2O5	19.77	H2O	76.77	H3PO4	27.30	H2O	69.24	"
34	90	CaO	1.26	NH3	3.04	P2O5	24.69	H2O	71.01	H3PO4	34.09	H2O	61.61	"
35	90	CaO	1.45	NH3	3.65	P2O5	29.56	H2O	65.34	H3PO4	40.82	H2O	54.08	"
36	90	CaO	1.75	NH3	4.23	P2O5	34.39	H2O	59.63	H3PO4	47.49	H2O	46.53	"
37	90	CaO	1.87	NH3	4.83	P2O5	39.17	H2O	54.13	H3PO4	54.09	H2O	39.21	"
38	90	CaO	2.22	NH3	5.46	P2O5	44.00	H2O	48.32	H3PO4	60.76	H2O	31.56	"
39	90	CaO	2.40	NH3	6.00	P2O5	48.83	H2O	42.77	H3PO4	67.43	H2O	24.17	"
40	90	CaO	1.51	NH3	6.67	P2O5	54.17	H2O	37.65	H3PO4	74.80	H2O	17.02	B + C

Part 2. The compiler has used the data in Part 1 to calculate the following molalities.
Solution number	Chemical₁	m₁ [mol/kg]	Chemical₂	m₂ [mol/kg]	Chemical₃	m₃ [mol/kg]
1	CaO	0.283	NH3	0.870	H3PO4	1.66
2	CaO	0.379	NH3	1.39	H3PO4	2.732
3	CaO	0.478	NH3	2.06	H3PO4	4.032
4	CaO	0.614	NH3	2.90	H3PO4	5.675
5	CaO	0.774	NH3	4.05	H3PO4	7.745
6	CaO	0.962	NH3	5.36	H3PO4	10.42
7	CaO	1.12	NH3	7.25	H3PO4	11.47
8	CaO	1.08	NH3	10.2	H3PO4	19.74
9	CaO	0.847	NH3	14.5	H3PO4	28.24
10	CaO	0.52	NH3	23.0	H3PO4	44.80
11	CaO	0.19	NH3	0.66	H3PO4	1.66
12	CaO	0.294	NH3	1.40	H3PO4	2.729
13	CaO	0.407	NH3	2.06	H3PO4	4.031
14	CaO	0.509	NH3	2.91	H3PO4	5.645
15	CaO	0.687	NH3	3.96	H3PO4	7.703
16	CaO	0.886	NH3	5.35	H3PO4	10.42
17	CaO	1.08	NH3	6.78	H3PO4	12.56
18	CaO	1.35	NH3	10.2	H3PO4	19.64
19	CaO	1.18	NH3	14.6	H3PO4	28.39
20	CaO	0.86	NH3	23.0	H3PO4	44.82
21	CaO	0.14	NH3	0.864	H3PO4	1.66
22	CaO	0.23	NH3	1.40	H3PO4	2.731
23	CaO	0.322	NH3	2.05	H3PO4	4.029
24	CaO	0.401	NH3	2.90	H3PO4	5.657
25	CaO	0.598	NH3	3.84	H3PO4	7.685
26	CaO	0.772	NH3	5.35	H3PO4	10.41
27	CaO	0.948	NH3	7.43	H3PO4	14.18
28	CaO	1.37	NH3	10.1	H3PO4	19.59
29	CaO	1.60	NH3	15.2	H3PO4	30.06
30	CaO	1.42	NH3	23.0	H3PO4	44.81
31	CaO	0.12	NH3	0.863	H3PO4	1.66
32	CaO	0.19	NH3	1.40	H3PO4	2.730
33	CaO	0.268	NH3	2.05	H3PO4	4.023
34	CaO	0.365	NH3	2.90	H3PO4	5.647
35	CaO	0.478	NH3	3.97	H3PO4	7.702
36	CaO	0.671	NH3	5.34	H3PO4	10.41
37	CaO	0.850	NH3	7.24	H3PO4	14.08
38	CaO	1.25	NH3	10.2	H3PO4	19.64
39	CaO	1.77	NH3	14.6	H3PO4	28.46
40	CaO	1.58	NH3	23.0	H3PO4	44.85

Notes:
   Table 1  ^a  These values were calculated by the compiler.
   Table 1  ^b  This is the water content of the CaO-NH₃–H₃PO₄-H₂O system.
   Table 1  ^c  The solid phases are: A=CaHPO₄; B=NH₄H₂PO₄; C=Ca(H₂PO₄)₂·H₂O.

Method/Apparatus/Procedure:
   An isothermal method¹ was used. Phosphoric acid neutralized by NH₃ to the chosen ratio was placed in round 350 ml vessels and stirred. CaO was then added in small amounts until a steady turbidity appeared. Equilibrium was ascertained by repeated analysis of the liquid phase for Ca. This was done complexometrically using fluorexon as indicator.² Equilibrium was reached in 4-6 hrs. The composition of the solid phase was determined petrographically and by chemical analysis.

Source and Purity of Materials:
   Chemically pure H₃PO₄ and aqueous ammonia and reagent grade CaO were used. The CaO was powdered and sifted through a 0.16 mm mesh sieve.

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

References:
   ¹Bergman, A.G.; Luzhnaya, N.P. Fizikokhimicheskiye Osnovy Izucheniya i Ispol'zovaniya Solyanykh Mestorozhdeniy Khlorid-Sul'fatnogo Tipa, Moscow, IAN SSSR, 1951.
   ²Moyzhes, I.B.; Ershova, V.A. Eds.; Metody Analiza pri Kontrole Proizvodstva Fosfora I Fosfornoy Kisloty Leningrad, 1968.