IUPAC-NIST Solubilities Database

IUPAC-NIST Solubility Database
NIST Standard Reference Database 106

Solubility System: Ammonium dihydrogenphosphate with Diammonium hydrogenphosphate, Triethylamine hydrochloride and Water

Components:
   (1) Ammonium dihydrogenphosphate; NH4H2PO4; [7722-76-1]  NIST Chemistry WebBook for detail
   (2) Diammonium hydrogenphosphate; (NH4)2HPO4; [7783-28-0]  NIST Chemistry WebBook for detail
   (3) Triethylamine hydrochloride; C6H16ClN; [554-68-7]  NIST Chemistry WebBook for detail
   (4) Water; H2O; [7732-18-5]  NIST Chemistry WebBook for detail

Original Measurements:
   Mazunin, S.A.; Sosnina, O.E.; Volkov, A.A.; Danina, T.L., Termicheskiy Analiz i Fazovye Ravnovesiya, Perm, 79 (1985).; Sosnina, O.E.; Volkov, A.A., Uch. Zap. Perm. Gos. Univ., Ser. Khim. 289, 20 (1973).

Variables:

   Concentration = Composition at 20 ºC and 60 ºC.

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

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

Solubility isotherms in the NH₄H₂PO₄-(NH₄)₂HPO₄-(C₂H₅)₃N·HCl-H₂O system.
t/°C	Chemical₁	10² * Mass Fraction w₁	m₁ [mol/kg]^(a)	Chemical₂	10² * Mass Fraction w₂	m₂ [mol/kg]^(a)	Chemical₃	10² * Mass Fraction w₃	m₃ [mol/kg]^(a)	Chemical₄	10² * Mass Fraction w₄	Solid Phase(s)^(b)
20	NH4H2PO4	1.2	0.24	(NH4)2HPO4	0.2	0.04	(C2H5)3N.HCl	56.0	9.90	H2O	42.6	A + B + C
20	NH4H2PO4	3.1	0.55	(NH4)2HPO4	1.0	0.15	(C2H5)3N.HCl	46.5	7.09	H2O	49.4	A + B
20	NH4H2PO4	5.7	0.90	(NH4)2HPO4	3.0	0.41	(C2H5)3N.HCl	36.3	4.97	H2O	55.0	"
20	NH4H2PO4	16.4	2.59	(NH4)2HPO4	11.9	1.64	(C2H5)3N.HCl	16.7	2.29	H2O	55.0	A (c)
20	NH4H2PO4	9.8	1.48	(NH4)2HPO4	6.4	0.84	(C2H5)3N.HCl	26.3	3.45	H2O	57.5	"
20	NH4H2PO4	22.9	4.08	(NH4)2HPO4	21.7	3.37	(C2H5)3N.HCl	6.6	1.0	H2O	48.8	-
20	NH4H2PO4	7.0	1.1	(NH4)2HPO4	4.0	0.53	(C2H5)3N.HCl	32.2	4.27	H2O	56.8	A (c)
20	NH4H2PO4	23.7	4.52	(NH4)2HPO4	26.4	4.38	(C2H5)3N.HCl	4.3	0.71	H2O	45.6	-
20	NH4H2PO4	5.8	0.91	(NH4)2HPO4	3.3	0.45	(C2H5)3N.HCl	35.3	4.78	H2O	55.6	A + B (c)
20	NH4H2PO4	24.4	4.94	(NH4)2HPO4	29.2	5.15	(C2H5)3N.HCl	3.5	0.61	H2O	42.9	-
20	NH4H2PO4	6.0	0.93	(NH4)2HPO4	3.7	0.50	(C2H5)3N.HCl	34.1	4.57	H2O	56.2	B (c)
20	NH4H2PO4	22.9	4.52	(NH4)2HPO4	29.4	5.06	(C2H5)3N.HCl	3.7	0.63	H2O	44.0	-
20	NH4H2PO4	5.8	0.84	(NH4)2HPO4	5.8	0.74	(C2H5)3N.HCl	28.7	3.62	H2O	59.7	B (c)
20	NH4H2PO4	19.2	3.52	(NH4)2HPO4	28.8	4.60	(C2H5)3N.HCl	4.6	0.73	H2O	47.4	-
20	NH4H2PO4	5.8	0.84	(NH4)2HPO4	6.3	0.80	(C2H5)3N.HCl	28.0	3.52	H2O	59.9	B (c)
20	NH4H2PO4	17.1	3.02	(NH4)2HPO4	28.7	4.41	(C2H5)3N.HCl	4.9	0.75	H2O	49.3	-
20	NH4H2PO4	7.0	1.0	(NH4)2HPO4	12.4	1.54	(C2H5)3N.HCl	19.8	2.45	H2O	60.8	B (c)
20	NH4H2PO4	12.3	1.96	(NH4)2HPO4	25.1	3.49	(C2H5)3N.HCl	8.1	1.1	H2O	54.5	-
20	NH4H2PO4	9.2	1.37	(NH4)2HPO4	21.0	2.73	(C2H5)3N.HCl	11.5	1.49	H2O	58.3	B
60	NH4H2PO4	4.0	1.0	(NH4)2HPO4	0.3	0.06	(C2H5)3N.HCl	60.6	13.0	H2O	35.1	A + B + C
60	NH4H2PO4	24.0	4.28	(NH4)2HPO4	9.1	1.4	(C2H5)3N.HCl	18.1	2.79	H2O	48.8	B
60	NH4H2PO4	16.9	2.93	(NH4)2HPO4	4.3	0.65	(C2H5)3N.HCl	28.7	4.32	H2O	50.1	A (c)
60	NH4H2PO4	28.6	5.55	(NH4)2HPO4	12.3	2.08	(C2H5)3N.HCl	14.3	2.40	H2O	44.8	-
60	NH4H2PO4	12.8	2.23	(NH4)2HPO4	3.5	0.53	(C2H5)3N.HCl	33.7	5.08	H2O	50.0	A (c)
60	NH4H2PO4	34.0	7.54	(NH4)2HPO4	20.7	4.00	(C2H5)3N.HCl	6.1	1.17	H2O	39.2	-
60	NH4H2PO4	9.8	1.8	(NH4)2HPO4	2.2	0.34	(C2H5)3N.HCl	39.5	6.14	H2O	48.5	A (c)
60	NH4H2PO4	35.4	8.72	(NH4)2HPO4	25.0	5.36	(C2H5)3N.HCl	4.3	0.92	H2O	35.3	-
60	NH4H2PO4	8.1	1.5	(NH4)2HPO4	1.6	0.26	(C2H5)3N.HCl	44.5	7.32	H2O	45.8	A (c)
60	NH4H2PO4	34.9	9.14	(NH4)2HPO4	28.5	6.50	(C2H5)3N.HCl	3.4	0.77	H2O	33.2	-
60	NH4H2PO4	6.6	1.35	(NH4)2HPO4	1.1	0.20	(C2H5)3N.HCl	49.9	8.87	H2O	42.4	A + B (c)
60	NH4H2PO4	34.0	9.85	(NH4)2HPO4	33.4	8.43	(C2H5)3N.HCl	2.6	0.65	H2O	30.0	-
60	NH4H2PO4	5.7	1.03	(NH4)2HPO4	2.4	0.38	(C2H5)3N.HCl	43.9	6.89	H2O	48.0	B (c)
60	NH4H2PO4	26.9	6.86	(NH4)2HPO4	35.3	7.84	(C2H5)3N.HCl	3.7	0.82	H2O	34.1	-
60	NH4H2PO4	4.7	0.77	(NH4)2HPO4	4.1	0.58	(C2H5)3N.HCl	37.9	5.36	H2O	53.3	B (c)
60	NH4H2PO4	19.6	4.22	(NH4)2HPO4	36.6	6.86	(C2H5)3N.HCl	3.4	0.63	H2O	40.4	-
60	NH4H2PO4	4.0	0.62	(NH4)2HPO4	5.4	0.73	(C2H5)3N.HCl	34.9	4.72	H2O	55.7	B (c)
60	NH4H2PO4	15.7	3.27	(NH4)2HPO4	38.6	7.01	(C2H5)3N.HCl	4.0	0.72	H2O	41.7	-
60	NH4H2PO4	2.4	0.35	(NH4)2HPO4	8.8	1.1	(C2H5)3N.HCl	29.4	3.73	H2O	59.4	B (c)
60	NH4H2PO4	7.1	1.3	(NH4)2HPO4	37.8	5.83	(C2H5)3N.HCl	6.0	0.92	H2O	49.1	-
60	NH4H2PO4	---	---	(NH4)2HPO4	19.0	2.37	(C2H5)3N.HCl	20.4	2.54	H2O	60.6	B (c)
60	NH4H2PO4	---	---	(NH4)2HPO4	35.8	5.01	(C2H5)3N.HCl	10.1	1.41	H2O	54.1	-

Notes:
   Table 1  ^a  The molalities were calculated by the compilers.
   Table 1  ^b  The solid phases are: A=NH₄H₂PO₄; B=(NH₄)₂HPO₄; C=(C₂H₅)₃)N·HCl.
   Table 1  ^c  Two layers of immiscible solutions were formed at these experimental points. The upper and lower lines refer to the upper and lower solution layer respectively.

Method/Apparatus/Procedure:
   The refractometric variation of the isothermal method was used. The compilers assume that it was the method described elsewhere.¹ NH₄H₂PO₄ and (NH₄)₂HPO₄ were determined by potentiometric titration. The composition of the solid phase was determined by the Schreinemaker's method.

Source and Purity of Materials:
   No information is given, but the compilers assume that the materials were the same as those used in.²

Estimated Errors:

   Temperature: The NH₄H₂PO₄ and (NH₄)₂HPO₄ contents have a precision of ±0.2 and ±0.6%, respectively.

References:
   ¹Zhuravlev, E.F.; Sheveleva, A.D. Zh. Neorg. Khim. 1960, 5, 2630.
   ²Sosnina, O.E.; Volkov, A.A. Uch. Zap. Perm. Gos. Univ., Ser. Khim. 1973, 289, 20.