IUPAC-NIST Solubilities Database

IUPAC-NIST Solubility Database
NIST Standard Reference Database 106

Solubility System: Ammonium dihydrogenphosphate with Ammonium chloride, Sodium dihydrogenphosphate, Sodium chloride and Water

Components:
   (1) Ammonium chloride; NH4Cl; [12125-02-9]  NIST Chemistry WebBook for detail
   (2) Ammonium dihydrogenphosphate; NH4H2PO4; [7722-76-1]  NIST Chemistry WebBook for detail
   (3) Sodium chloride; NaCl; [7647-14-5]  NIST Chemistry WebBook for detail
   (4) Sodium dihydrogenphosphate; NaH2PO4; [7558-80-7]  NIST Chemistry WebBook for detail
   (5) Water; H2O; [7732-18-5]  NIST Chemistry WebBook for detail

Original Measurements:
   Solov'ev, A.P.; Balashova, E.F.; Verendykina, N.A.; Zyuzina, L.F., Vzaimodeistvie Khloridov Kaliya, Magniya, Ammoniya s ikh Nitratami i Fosfatami 1977, 3.

Variables:

   Concentration = Composition at 25 ºC.

Prepared By:
   J. Eysseltová

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

Solubility in the Na⁺, NH₄⁺||Cl^–, H₂PO₄^–-H₂O system at 25 °C.
Chemical₁	10² * Mass Fraction w₁	m₁^(a)	Chemical₂	10² * Mass Fraction w₂	m₂^(a)	Chemical₃	10² * Mass Fraction w₃	m₃^(a)	Chemical₄	10² * Mass Fraction w₄	m₄^(a)	Chemical₅	Chemical₆	Solid Phase(s)^(b)
NaH2PO4	25.01	3.48	NaCl	15.13	4.33	NH4H2PO4	---	---	NH4Cl	---	---	Na+	H2PO4-	A + B
NaH2PO4	24.74	3.63	NaCl	13.97	4.21	NH4H2PO4	4.55	0.70	NH4Cl	---	---	Na+	H2PO4-	A + B
NaH2PO4	23.26	3.51	NaCl	12.90	4.00	NH4H2PO4	8.59	1.35	NH4Cl	---	---	Na+	H2PO4-	A + B
NaH2PO4	24.19	3.85	NaCl	11.01	3.60	NH4H2PO4	12.40	2.06	NH4Cl	---	---	Na+	H2PO4-	A + B + C
NaH2PO4	43.47	8.12	NaCl	---	---	NH4H2PO4	11.93	2.35	NH4Cl	---	---	Na+	H2PO4-	B + C
NaH2PO4	38.32	7.25	NaCl	4.54	1.76	NH4H2PO4	13.11	2.59	NH4Cl	---	---	Na+	H2PO4-	B + C
NaH2PO4	32.90	5.20	NaCl	8.00	2.96	NH4H2PO4	12.79	2.40	NH4Cl	---	---	Na+	H2PO4-	B + C
NaH2PO4	30.54	5.37	NaCl	9.33	3.37	NH4H2PO4	12.78	2.35	NH4Cl	---	---	Na+	H2PO4-	B + C
NaH2PO4	12.30	1.78	NaCl	16.87	4.96	NH4H2PO4	12.58	1.88	NH4Cl	---	---	Na+	H2PO4-	A + C
NaH2PO4	---	---	NaCl	20.85	5.75	NH4H2PO4	17.10	2.40	NH4Cl	---	---	Na+	H2PO4-	A + C
NaH2PO4	---	---	NaCl	16.07	4.21	NH4H2PO4	5.64	0.75	NH4Cl	12.93	3.70	Na+	H2PO4-	A + C + D
NaH2PO4	---	---	NaCl	17.07	4.41	NH4H2PO4	2.82	0.37	NH4Cl	13.88	3.92	Na+	H2PO4-	A + D
NaH2PO4	---	---	NaCl	17.15	4.40	NH4H2PO4	---	---	NH4Cl	16.14	4.52	Na+	H2PO4-	A + D
NaH2PO4	---	---	NaCl	8.68	2.18	NH4H2PO4	4.48	0.57	NH4Cl	18.75	5.15	Na+	H2PO4-	C + D
NaH2PO4	---	---	NaCl	5.89	1.48	NH4H2PO4	5.15	0.66	NH4Cl	21.11	5.82	Na+	H2PO4-	C + D
NaH2PO4	---	---	NaCl	1.59	0.39	NH4H2PO4	5.60	0.70	NH4Cl	22.91	6.13	Na+	H2PO4-	C + D
NaH2PO4	---	---	NaCl	---	---	NH4H2PO4	6.12	0.78	NH4Cl	25.54	6.98	Na+	H2PO4-	C + D

Notes:
   Table 1  ^a  These values were calculated by the compiler.
   Table 1  ^b  The solid phases are: A=NCl; B=NaH₂PO₄·2H₂O; C=NH₄H₂PO₄; D=NH₄Cl.
   Table 1  ^c  In the original article these values were designated as ion %. The compiler believes that the units here are: mol/100 mol of solute.

Method/Apparatus/Procedure:
   The method of invariant points was used. A third component was added to eutectic systems until a new solid phase appeared. At equilibrium both liquid and solid phases were analyzed. Chloride ion content was determined by the Volhard method. H₂PO₄^– ions were precipitated as NH₄MgPO₄·6H₂O, and the excess of Mg was titrated complexometrically.¹. Ammonium ions were removed and the excess of base was titrated with HCl.

Source and Purity of Materials:
   No information is given.

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

References:
   ¹F. M. Shemyakin, E. N. Zelenina, Zavod. Lab. 6 (1969).