IUPAC-NIST Solubilities Database

IUPAC-NIST Solubility Database
NIST Standard Reference Database 106

Solubility System: Ammonia with Phosphoric acid, Hydrogen chloride and Water

Components:
   (1) Ammonia; NH3; [7664-41-7]  NIST Chemistry WebBook for detail
   (2) Hydrogen chloride; HCl; [7647-01-0]  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:
   Grantscharov, I.N., Dokl. Bolg. Akad. Nauk 1976, 29, 669.

Variables:

   Concentration = Composition and temperature.

Prepared By:
   J. Eysseltová

Experimental Remarks:

   Remarks: The following two empirical equations are also given in the paper. N + P₂O₅ = a + b(P₂O₅/N) [1] This is valid in all crystallization fields in this system. N and P₂O₅ are the respective concentrations in mass %. a and b are constants which depend only on temperature. N + P₂O₅ = 7.29 + 0.105t + 2.615(P₂O₅/N) + 0.0459t(P₂O₅/N)[2] This equation is valid only in the crystallization field of NH₄H₂PO₄.

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

Monovariant points in the NH₄Cl-NH₄H₂PO₄-(NH₄)₂HPO₄-H₂O system when the ratio NH₃:H₃PO₄ = 1.2.
Solution number	t/°C	Chemical₁	10² * Mass Fraction w₁	Chemical₂	10² * Mass Fraction w₂	Chemical₃	10² * Mass Fraction w₃	Solid Phase(s)^(a)
1	-14.5	NH4Cl	19.5	(NH4)1.2H1.8PO4	0.0	H2O	80.5	A + B
2	-15.2	NH4Cl	17.6	(NH4)1.2H1.8PO4	4.2	H2O	78.2	"
3	-15.0	NH4Cl	17.1	(NH4)1.2H1.8PO4	5.3	H2O	77.6	A + C
4	-13.5	NH4Cl	13.6	(NH4)1.2H1.8PO4	8.7	H2O	77.7	"
5	-12.0	NH4Cl	12.6	(NH4)1.2H1.8PO4	10.0	H2O	77.4	"
6	-11.0	NH4Cl	8.5	(NH4)1.2H1.8PO4	14.0	H2O	77.5	"
7	-10.0	NH4Cl	7.6	(NH4)1.2H1.8PO4	13.9	H2O	78.5	"
8	-7.5	NH4Cl	4.0	(NH4)1.2H1.8PO4	19.0	H2O	77.0	"
9	-7.4	NH4Cl	3.0	(NH4)1.2H1.8PO4	19.4	H2O	77.6	"
10	-6.4	NH4Cl	1.0	(NH4)1.2H1.8PO4	22.8	H2O	76.2	"
11	-5.8	NH4Cl	0.0	(NH4)1.2H1.8PO4	25.0	H2O	75.0	"
12	-7.5	NH4Cl	19.0	(NH4)1.2H1.8PO4	5.0	H2O	76.0	B + C
13	0.0	NH4Cl	20.9	(NH4)1.2H1.8PO4	5.6	H2O	73.5	"
14	9.5	NH4Cl	22.7	(NH4)1.2H1.8PO4	5.8	H2O	71.5	"
15	19.0	NH4Cl	24.3	(NH4)1.2H1.8PO4	6.8	H2O	68.9	"
16	25.6	NH4Cl	25.2	(NH4)1.2H1.8PO4	7.5	H2O	67.3	"
17	30.5	NH4Cl	25.7	(NH4)1.2H1.8PO4	8.5	H2O	65.8	"
18	41.0	NH4Cl	27.0	(NH4)1.2H1.8PO4	10.0	H2O	63.0	"

Part 2. The compiler has calculated the following values from the data in Part 1.
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	Mass Fraction w₄^{mass %}
1	NH3	6.2	4.5	H3PO4	0.0	0.0	HCl	13.3	4.53	H2O	80.5
2	NH3	6.3	4.8	H3PO4	3.5	0.46	HCl	12.0	4.21	H2O	78.2
3	NH3	6.4	4.8	H3PO4	4.4	0.58	HCl	11.7	4.12	H2O	77.6
4	NH3	5.8	4.4	H3PO4	7.3	0.95	HCl	9.3	3.3	H2O	77.7
5	NH3	5.8	4.4	H3PO4	8.4	1.1	HCl	8.6	3.0	H2O	77.4
6	NH3	5.2	3.9	H3PO4	11.7	1.54	HCl	5.8	2.0	H2O	77.5
7	NH3	4.8	3.6	H3PO4	11.6	1.51	HCl	5.2	1.8	H2O	78.5
8	NH3	4.6	3.5	H3PO4	15.9	2.10	HCl	2.7	0.97	H2O	77.0
9	NH3	4.3	3.3	H3PO4	16.2	2.13	HCl	2.0	0.72	H2O	77.6
10	NH3	4.3	3.3	H3PO4	19.1	2.55	HCl	0.7	0.2	H2O	76.2
11	NH3	4.4	3.4	H3PO4	20.9	2.84	HCl	0.0	0.0	H2O	75.0
12	NH3	6.9	5.4	H3PO4	4.2	0.56	HCl	13.0	4.67	H2O	76.0
13	NH3	7.6	6.1	H3PO4	4.7	0.65	HCl	14.2	5.32	H2O	73.5
14	NH3	8.2	6.8	H3PO4	4.8	0.69	HCl	15.5	5.93	H2O	71.5
15	NH3	8.9	7.6	H3PO4	5.7	0.84	HCl	16.6	6.59	H2O	68.9
16	NH3	9.3	8.1	H3PO4	6.3	0.95	HCl	17.2	7.00	H2O	67.3
17	NH3	9.7	8.6	H3PO4	7.1	1.1	HCl	17.5	7.30	H2O	65.8
18	NH3	10.3	9.64	H3PO4	8.4	1.4	HCl	18.4	8.01	H2O	63.0

Notes:
   Table 1  ^a  The solid phases are : A=ice; B=NH₄Cl; C=NH₄H₂PO₄

Method/Apparatus/Procedure:
   A visual polythermic method was used. The apparatus was self-constructed.¹

Source and Purity of Materials:
   Reagent grade salts were recrystallized and dried at 30 °C to 50 °C.

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

References:
   ¹Grantscharov, I.N.; Ivanov, D.G. God. na VKhTI 1968, 15, 127.