IUPAC-NIST Solubilities Database

IUPAC-NIST Solubility Database
NIST Standard Reference Database 106

Solubility System: Ammonium dihydrogenphosphate with Diammonium carbonate, Potassium dihydrogenphosphate, Dipotassium carbonate and Water

Components:
   (1) Ammonium dihydrogenphosphate; NH4H2PO4; [7722-76-1]  NIST Chemistry WebBook for detail
   (2) Diammonium carbonate; (NH4)2CO3; [506-87-6]  NIST Chemistry WebBook for detail
   (3) Dipotassium carbonate; K2CO3; [584-08-7]  NIST Chemistry WebBook for detail
   (4) Potassium dihydrogenphosphate; KH2PO4; [7778-77-0]  NIST Chemistry WebBook for detail
   (5) Water; H2O; [7732-18-5]  NIST Chemistry WebBook for detail

Original Measurements:
   Syromyatnikova, M.N.; Torocheshnikov, A.B.; Kuznetsova, Zh. Prikl. Kim (Leningrad) 52, 568 (1979).

Variables:

   Concentration = Composition at 0 ºC, 10 ºC, 20 ºC and 30 ºC.

Prepared By:
   J. Eysseltová

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

Solubility in the NH₄H₂PO₄-K₂CO₃-H₂O system.
t/°C	Chemical₁	10² * Mass Fraction w₁	Chemical₂	10² * Mass Fraction w₂	Chemical₃	10² * Mass Fraction w₃	Chemical₄	10² * Mass Fraction w₄	Mass Ratio	Solid Phase(s)^(b)
0	N	2.25	P2O5	11.40	K2O	---	E (a)	13.65	1 : 5.07 : 0 (N : P2O5 : K2O)	-
0	N	3.56	P2O5	20.07	K2O	14.70	E	38.83	1 : 5.64 : 4.14	A + B + C
0	N	3.12	P2O5	20.40	K2O	15.31	E	38.83	1 : 5.54 : 4.91	A + B + C
0	N	3.13	P2O5	16.31	K2O	16.00	E	35.44	1 : 5.20 : 5.10	A + B
0	N	1.54	P2O5	8.40	K2O	13.38	E	23.32	1 : 5.45 : 8.68	-
0	N	1.72	P2O5	9.27	K2O	14.89	E	25.88	1 : 5.40 : 8.50	A + D + E(tr)
0	N	1.47	P2O5	8.70	K2O	19.10	E	29.27	1 : 5.92 : 12.99	A + D + E(tr)
0	N	1.08	P2O5	9.76	K2O	26.46	E	37.30	1 : 9.07 : 24.60	A + D + F(tr)
0	N	0.7	P2O5	6.55	K2O	29.35	E	36.60	1 : 9.34 : 41.81	-
0	N	0.5	P2O5	6.36	K2O	28.88	E	35.74	1 : 12.60 : 57.7	A + B + E(tr) +F(tr)
0	N	0.39	P2O5	3.17	K2O	29.00	E	32.56	1 : 8.12 : 74.0	-
10	N	2.77	P2O5	14.10	K2O	---	E	16.87	1 : 5.09 : 0	-
10	N	4.98	P2O5	24.60	K2O	4.34	E	33.92	1 : 4.92 : 0.87	-
10	N	6.05	P2O5	26.70	K2O	9.16	E	41.92	1 : 4.40 : 1.51	-
10	N	5.45	P2O5	22.70	K2O	8.15	E	36.30	1 : 4.18 : 1.50	-
10	N	5.18	P2O5	23.60	K2O	13.14	E	41.92	1 : 4.56 : 2.54	-
10	N	4.80	P2O5	19.80	K2O	14.70	E	39.30	1 : 4.13 : 4.50	--
10	N	4.33	P2O5	21.00	K2O	15.70	E	41.03	1 : 4.85 : 3.64	-
10	N	3.53	P2O5	19.95	K2O	16.10	E	39.58	1 : 5.66 : 4.57	-
10	N	3.05	P2O5	19.40	K2O	16.25	E	38.70	1 : 6.40 : 5.3	-
10	N	2.70	P2O5	17.42	K2O	15.91	E	36.03	1 : 6.46 : 5.9	-
10	N	2.10	P2O5	13.77	K2O	16.50	E	32.37	1 : 6.58 : 7.96	-
10	N	2.89	P2O5	14.30	K2O	18.90	E	36.09	1 : 5.14 : 6.78	-
10	N	1.59	P2O5	11.70	K2O	22.10	E	35.39	1 : 7.35 : 13.9	-
10	N	1.27	P2O5	10.12	K2O	26.00	E	37.39	1 : 9.96 : 20.45	-
10	N	0.7	P2O5	12.00	K2O	26.90	E	39.60	1 : 17.10 : 38.20	-
10	N	0.44	P2O5	4.99	K2O	31.80	E	37.23	1 : 11.4 : 72.4	-
20	N	3.31	P2O5	16.78	K2O	---	E	20.09	1 : 5.08 : 0	-
20	N	6.30	P2O5	29.50	K2O	7.25	E	43.05	1 : 4.68 : 1.15	A + B + C
20	N	4.79	P2O5	27.20	K2O	15.28	E	47.27	1 : 3.65 : 3.18	A + B + C
20	N	4.01	P2O5	25.90	K2O	18.90	E	48.81	1 : 0.45 : 4.7	A + B + C
20	N	3.80	P2O5	22.00	K2O	16.55	E	42.35	1 : 5.78 : 4.35	A + B + C
20	N	3.48	P2O5	25.00	K2O	20.90	E	49.38	1 : 7.18 : 6.0	A + B + C
20	N	2.70	P2O5	15.90	K2O	17.90	E	36.50	1 : 5.89 : 6.62	A + D
20	N	0.47	P2O5	8.27	K2O	25.60	E	34.34	1 : 17.6 : 54.5	A + G
20	N	1.09	P2O5	4.30	K2O	29.75	E	35.14	1 : 3.95 : 27.3	A + G
30	N	3.86	P2O5	19.55	K2O	---	E	23.41	1 : 5.07 : 0	-
30	N	6.12	P2O5	32.17	K2O	8.81	E	47.10	1 : 5.26 : 1.44	-
30	N	4.56	P2O5	27.58	K2O	17.19	E	49.33	1 : 6.05 : 3.77	-
30	N	3.84	P2O5	21.10	K2O	18.05	E	42.99	1 : 5.49 : 4.7	-
30	N	3.50	P2O5	24.58	K2O	22.32	E	50.40	1 : 7.02 : 6.38	-
30	N	4.42	P2O5	26.80	K2O	17.20	E	48.42	1 : 6.06 : 3.89	-
30	N	3.56	P2O5	25.36	K2O	20.78	E	49.70	1 : 7.12 : 5.84	-
30	N	3.02	P2O5	16.10	K2O	19.48	E	38.60	1 : 5.33 : 6.45	-
30	N	2.64	P2O5	13.42	K2O	26.30	E	42.36	1 : 5.08 : 9.96	-
30	N	0.04	P2O5	5.00	K2O	30.92	E	35.96	1 :125 :733	-

Notes:
   Table 1  ^a  This is the total plant nutrient.
   Table 1  ^b  The solid phases are: A=KHCO₃; B=NH₄H₂PO₄; C=K₂HPO₄; C=K₂HPO₄; E=(NH₄)₂CO₃·H₂O; F=K₂CO₃·1.5H₂O; G=K₂HPO₄·3H₂O; (tr)=traces.

Method/Apparatus/Procedure:
   The isothermal method was used. Mixtures were prepared in 100 ml glass vessels by adding solid NH₄H₂PO₄ to satd solns of K₂CO₃ and by adding solid K₂CO₃ to satd solns of NH₄H₂PO₄. The mixtures were placed in a water thermostat and agitated for 3.5 hrs. The phases were separated from each other by filtration. The liquid phase was analyzed for ammonia,¹ phosphate ion ² and potassium ² The identity of the solid phase was determined by X-ray analysis.

Source and Purity of Materials:
   Pure K₂CO₃ and reagent grade NH₄H₂PO₄ were used.

Estimated Errors:
   Solubility: No information given.
   Temperature: The temperature was controlled to within ± 0.05 K.

References:
   ¹ Shokin, I.N.; Krasheninikov, S.A.; et al. Tekhnicheskiy Analiz i Kontrol' v Proizvodstve Neorganicheskikh Veshchestv, Izd. Vysshaya Shkola, Moscow 1968.
   ² Kel'man, F.N.; Bruckus, E.B.; Osherovich, R.F. Metody Analiza pri Kontrole Proizvodstva Sernoy Kisloty i Fosfornykh Udobreniy, Goskhimizdat, Moscow 1963.