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IUPAC-NIST Solubility Database
NIST Standard Reference Database 106
Solubility System:
Ammonium dihydrogenphosphate with Thiourea and Water
Components:
(1) Ammonium dihydrogenphosphate; NH4H2PO4; [7722-76-1]
NIST Chemistry WebBook
for detail
(2) Thiourea; CH4N2S; [62-56-6]
NIST Chemistry WebBook
for detail
(3) Water; H2O; [7732-18-5]
NIST Chemistry WebBook
for detail
Original Measurements:
Zakirov, B.S.; Tukhtaev, S.; Beglov, B.M., Uzb. Khim. Zh. 1974, 19.
Variables:
Concentration = Composition and temperature.
Prepared By:
J. Eysseltová
Experimental Remarks:
Remarks: Additional Data: Solubility isotherms in the 0 ºC to 50 ºC temperature range are given, but only in graphical form.
Experimental Data:
(Notes on the Nomenclature)
(Please see footnotes following the table(s).)
Points of simultaneous crystallization of two or three solid phases in the NH
4
H
2
PO
4
-CS(NH
2
)
2
-H
2
O system.
t/°C
Chemical
1
10
2
* Mass Fraction w
1
m
1
[mol/kg]
(a)
Chemical
2
10
2
* Mass Fraction w
2
m
2
[mol/kg]
(a)
Chemical
3
10
2
* Mass Fraction w
3
Solid Phase(s)
(b)
-0.6
NH4H2PO4
0
0
CS(NH2)2
5.2
0.72
H2O
94.8
A + B
-2.0
NH4H2PO4
4.8
0.46
CS(NH2)2
4.1
0.59
H2O
91.1
A + B
-3.1
NH4H2PO4
9.6
0.96
CS(NH2)2
3.5
0.53
H2O
86.9
A + B
-4.2
NH4H2PO4
14.5
1.53
CS(NH2)2
3.2
0.51
H2O
82.3
A + B
-4.5
NH4H2PO4
15.8
1.70
CS(NH2)2
3.2
0.52
H2O
81.0
A + B + C
-4.2
NH4H2PO4
18.0
1.91
CS(NH2)2
0
0
H2O
82.0
A + D
1.0
NH4H2PO4
17.2
1.90
CS(NH2)2
4.2
0.70
H2O
78.6
B + D
7.5
NH4H2PO4
18.9
2.17
CS(NH2)2
5.3
0.92
H2O
75.8
B + D
22.5
NH4H2PO4
22.7
2.84
CS(NH2)2
7.8
1.5
H2O
69.5
B + D
28.0
NH4H2PO4
24.5
3.20
CS(NH2)2
9.0
1.8
H2O
66.5
B + D + E
33.0
NH4H2PO4
32.4
4.17
CS(NH2)2
0
0
H2O
67.6
D + E
36.8
NH4H2PO4
27.0
3.79
CS(NH2)2
11.0
2.33
H2O
62.0
B + E
50.6
NH4H2PO4
30.8
4.83
CS(NH2)2
13.8
3.27
H2O
55.4
B + E
Notes:
Table 1
a
These values were calculated by the compiler.
Table 1
b
The solid phases are: A=ice; B=CS(NH
2
)
2
; C-NH
4
H
2
PO
4
; D=α-NH
4
H
2
PO
4
; E=β-NH
4
H
2
PO
4
.
Method/Apparatus/Procedure:
A visual polythermic method was used.
Source and Purity of Materials:
"Chemically pure" NH
4
H
2
PO
4
was used. The thiourea was recrystallized twice.
Estimated Errors:
Solubility: No information is given.
Temperature: No information is given.