IUPAC-NIST Solubility Database
NIST Standard Reference Database 106

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 Solubility System: Ammonium dihydrogenphosphate with Diammonium hydrogenphosphate, Potassium sulfate and Water

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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) Potassium sulfate; K2SO4; [7778-80-5]  NIST Chemistry WebBook for detail
   (4) Water; H2O; [7732-18-5]  NIST Chemistry WebBook for detail

Original Measurements:
   Tishchenko, I.N.; Kuznetsova, A.G., VINITI 1981, 2594, 12

Variables:

   Concentration = Composition at 0 ºC

Prepared By:
   J. Eysseltová

Experimental Data:   (Notes on the Nomenclature)
  

Solubility in the (NH₄)₂HPO₄-NH₄H₂PO₄-K₂SO₄-H₂O system at 0 °C.

Solution number	Chemical1	102 * Mass Fraction w1	Chemical2	102 * Mass Fraction w2	Chemical3	102 * Mass Fraction w3	Comment(s)
1	N	6.31	P2O5	21.40	K2O	9.00	original mixture
2	N	6.98	P2O5	23.07	K2O	9.00	original mixture
3	N	6.65	P2O5	20.72	K2O	9.00	original mixture
4	N	6.52	P2O5	22.04	K2O	9.00	original mixture
5	N	6.81	P2O5	22.98	K2O	9.00	original mixture
6	N	7.35	P2O5	24.92	K2O	9.00	original mixture
7	N	8.50	P2O5	28.75	K2O	9.00	original mixture
8	N	9.87	P2O5	33.58	K2O	9.00	original mixture
9	N	8.42	P2O5	27.61	K2O	9.00	original mixture
10	N	9.73	P2O5	31.88	K2O	9.00	original mixture
11	N	7.39	P2O5	23.10	K2O	9.00	original mixture
12	N	8.53	P2O5	27.32	K2O	9.00	original mixture
13	N	9.95	P2O5	31.03	K2O	9.00	original mixture
14	N	10.80	P2O5	32.99	K2O	9.00	original mixture
1	N	6.75	P2O5	21.96	K2O	3.81	equilibrium liquid phase
2	N	7.66	P2O5	23.35	K2O	3.62	equilibrium liquid phase
3	N	7.02	P2O5	21.92	K2O	3.83	equilibrium liquid phase
4	N	6.99	P2O5	23.78	K2O	4.19	equilibrium liquid phase
5	N	7.53	P2O5	24.95	K2O	3.51	equilibrium liquid phase
6	N	7.98	P2O5	26.00	K2O	4.01	equilibrium liquid phase
7	N	8.52	P2O5	26.57	K2O	3.88	equilibrium liquid phase
8	N	8.28	P2O5	27.77	K2O	3.60	equilibrium liquid phase
9	N	8.03	P2O5	25.88	K2O	3.60	equilibrium liquid phase
10	N	8.35	P2O5	26.78	K2O	3.01	equilibrium liquid phase
11	N	8.05	P2O5	25.44	K2O	3.23	equilibrium liquid phase
12	N	8.25	P2O5	27.48	K2O	3.58	equilibrium liquid phase
13	N	8.32	P2O5	27.40	K2O	3.70	equilibrium liquid phase
14	N	8.26	P2O5	26.97	K2O	3.52	equilibrium liquid phase

Method/Apparatus/Procedure:
   K₂SO₄ was added to 50 g of a soln saturated with ammonium phosphates or a suspension of proper overall composition. The equilibrium vessels were thermostated in an ice-water bath for 4 hrs. The equilibrium liquid phase was analyzed for NH₄⁺, PO₄^3– and K⁺.¹

Source and Purity of Materials:
   No information is given.

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

References:
   ¹Vinnik, M.M.; Erbanova, L.N.; et al. Metody Analiza Fosfatnogo Syrya, Moscow 1975.

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