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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 NH
4
H
2
PO
4
-K
2
CO
3
-H
2
O system.
t/°C
Chemical
1
10
2
* Mass Fraction w
1
Chemical
2
10
2
* Mass Fraction w
2
Chemical
3
10
2
* Mass Fraction w
3
Chemical
4
10
2
* Mass Fraction w
4
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=KHCO
3
; B=NH
4
H
2
PO
4
; C=K
2
HPO
4
; C=K
2
HPO
4
; E=(NH
4
)
2
CO
3
·H
2
O; F=K
2
CO
3
·1.5H
2
O; G=K
2
HPO
4
·3H
2
O; (tr)=traces.
Method/Apparatus/Procedure:
The isothermal method was used. Mixtures were prepared in 100 ml glass vessels by adding solid NH
4
H
2
PO
4
to satd solns of K
2
CO
3
and by adding solid K
2
CO
3
to satd solns of NH
4
H
2
PO
4
. 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 K
2
CO
3
and reagent grade NH
4
H
2
PO
4
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.