IUPAC-NIST Solubilities Database

IUPAC-NIST Solubility Database
NIST Standard Reference Database 106

Solubility System: Ammonium dihydrogenphosphate with Diammonium sulfate and Water

Components:
   (1) Ammonium dihydrogenphosphate; NH4H2PO4; [7722-76-1]  NIST Chemistry WebBook for detail
   (2) Diammonium sulfate; (NH4)2SO4; [7783-20-2]  NIST Chemistry WebBook for detail
   (3) Water; H2O; [7732-18-5]  NIST Chemistry WebBook for detail

Original Measurements:
   Shenkin, Ya.S.; Freyman, O.I., Zh. Neorg. Khim. 1970, 15, 3151.

Variables:

   Concentration = Temperature and composition at atmospheric pressure.

Prepared By:
   J. Eysseltová

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

Solubility in the (NH₄)₂SO₄-NH₄H₂PO₄-H₂O system at atmospheric pressure.
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	Mole Fraction₃^{-lg N (c)}	Solid Phase(s)
8.95	(NH4)2SO4	50.75	7.80	NH4H2PO4	0.00	0.00	H2O	49.25	0.063	(NH4)2SO4
9.5	(NH4)2SO4	49.22	7.83	NH4H2PO4	3.21	0.59	H2O	47.57	0.061	(NH4)2SO4
9.6	(NH4)2SO4	47.50	7.75	NH4H2PO4	6.11	1.14	H2O	46.39	0.065	(NH4)2SO4
10.2	(NH4)2SO4	45.45	7.46	NH4H2PO4	8.43	1.59	H2O	46.12	0.064	(NH4)2SO4
10.2	(NH4)2SO4	42.50	7.00	NH4H2PO4	11.58	2.19	H2O	45.92	0.067	(NH4)2SO4
10.3	(NH4)2SO4	40.93	6.79	NH4H2PO4	13.48	2.57	H2O	45.59	0.066	(NH4)2SO4
10.4	(NH4)2SO4	38.50	6.68	NH4H2PO4	17.90	3.57	H2O	43.60	0.072	(NH4)2SO4
10.7	(NH4)2SO4	37.50	6.68	NH4H2PO4	20.05	4.10	H2O	42.45	0.077	(NH4)2SO4
11.1	(NH4)2SO4	35.50	6.40	NH4H2PO4	22.50	4.66	H2O	42.00	0.080	(NH4)2SO4
11.4	(NH4)2SO4	34.50	6.37	NH4H2PO4	24.51	5.20	H2O	40.99	0.084	(NH4)2SO4
11.4	(NH4)2SO4	33.50	6.29	NH4H2PO4	26.21	5.65	H2O	40.29	0.085	(NH4)2SO4
11.5	(NH4)2SO4	32.50	6.15	NH4H2PO4	27.50	5.97	H2O	40.00	0.086	(NH4)2SO4
11.9	(NH4)2SO4	31.10	5.98	NH4H2PO4	29.56	6.53	H2O	39.34	0.091	(NH4)2SO4
12.6	(NH4)2SO4	30.20	6.13	NH4H2PO4	32.52	7.58	H2O	37.28	0.105	(NH4)2SO4
12.7	(NH4)2SO4	27.83	5.66	NH4H2PO4	34.98	8.17	H2O	37.19	0.096	(NH4)2SO4
12.7	(NH4)2SO4	26.98	5.74	NH4H2PO4	37.47	9.16	H2O	35.55	0.105	(NH4)2SO4
12.9	(NH4)2SO4	25.50	5.51	NH4H2PO4	39.50	9.81	H2O	35.00	0.106	(NH4)2SO4
13.6	(NH4)2SO4	24.51	5.62	NH4H2PO4	42.51	11.20	H2O	32.98	0.110	(NH4)2SO4
14.5	(NH4)2SO4	23.52	5.64	NH4H2PO4	44.91	12.36	H2O	31.57	0.122	(NH4)2SO4
14.9	(NH4)2SO4	23.03	5.73	NH4H2PO4	46.53	13.28	H2O	30.44	0.128	(NH4)2SO4
15.1	(NH4)2SO4	22.50	5.70	NH4H2PO4	47.62	13.85	H2O	29.88	0.130	(NH4)2SO4
15.8	(NH4)2SO4	22.50	5.87	NH4H2PO4	48.51	14.54	H2O	28.99	0.137	(NH4)2SO4
16.1	(NH4)2SO4	22.40	6.15	NH4H2PO4	50.05	15.79	H2O	27.55	0.146	(NH4)2SO4
17.9	(NH4)2SO4	22.41	6.75	NH4H2PO4	52.47	18.15	H2O	25.12	0.160	(NH4)2SO4
18.3	(NH4)2SO4	22.40	6.86	NH4H2PO4	52.89	18.60	H2O	24.71	0.164	(NH4)2SO4
17.8	(NH4)2SO4	20.84	6.28	NH4H2PO4	54.06	18.72	H2O	25.10	0.162	NH4H2PO4
16.1	(NH4)2SO4	19.75	6.04	NH4H2PO4	55.50	19.49	H2O	24.75	1.666d	NH4H2PO4
15.4	(NH4)2SO4	17.97	5.33	NH4H2PO4	56.51	19.24	H2O	25.52	1.660d	NH4H2PO4
14.8	(NH4)2SO4	16.10	4.61	NH4H2PO4	57.45	18.88	H2O	26.45	0.153	NH4H2PO4
15.3	(NH4)2SO4	15.98	4.57	NH4H2PO4	57.55	18.89	H2O	26.47	0.154	NH4H2PO4
13.7	(NH4)2SO4	13.01	3.65	NH4H2PO4	60.04	19.36	H2O	26.95	0.151	NH4H2PO4
13.1	(NH4)2SO4	12.50	3.45	NH4H2PO4	60.07	19.03	H2O	27.43	0.149	NH4H2PO4
12.4	(NH4)2SO4	10.04	2.74	NH4H2PO4	62.25	19.52	H2O	27.71	0.147	NH4H2PO4
11.8	(NH4)2SO4	7.52	2.02	NH4H2PO4	64.30	19.83	H2O	28.18	0.144	NH4H2PO4
10.9	(NH4)2SO4	3.51	0.92	NH4H2PO4	67.52	20.25	H2O	28.97	0.141	NH4H2PO4
9.4	(NH4)2SO4	0.00	0.00	NH4H2PO4	71.08	21.36	H2O	28.92	0.142	NH4H2PO4

Notes:
   Table 1  ^a  These values were calculated by the compiler. The unit is: mol kg^–1.
   Table 1  ^b  This is the difference between the boiling point of the saturated solution and the boiling point of water.
   Table 1  ^c  N is the mol fraction of water.
   Table 1  ^d  These are obvious typographical errors. The correct values should be 0.167 and 0.166, respectively.

Method/Apparatus/Procedure:
   The method was the same as that described earlier.¹

Source and Purity of Materials:
   No information is given.

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

References:
   ¹Shenkin, Ya.S.; Ruchnova, S.A.; Shenkina, A.P. Zh. Neorg. Khim. 1968, 13, 256.