IUPAC-NIST Solubility Database
NIST Standard Reference Database 106

Glass Ball as Bullet Solubility System: Ammonium dihydrogenphosphate with Diammonium dihydrogendiphosphate and Water

   (1) Ammonium dihydrogenphosphate; NH4H2PO4; [7722-76-1]  NIST Chemistry WebBook for detail
   (2) Diammonium dihydrogendiphosphate; (NH4)2H2P2O7; [13597-86-9]  NIST Chemistry WebBook for detail
   (3) Water; H2O; [7732-18-5]  NIST Chemistry WebBook for detail

Original Measurements:
   Chulanova, G.A.; Mukhina, L.S.; Shipyatskaya, R.I.; Taran, A.I., Zh. Prikl. Khim. (Leningrad) 1976, 49, 1933.


   Concentration = Composition at 50 °C and 70 °C

Prepared By:
   J. Eysseltová

Experimental Data:   (Notes on the Nomenclature)
(Please see footnotes following the table(s).)
t/°CChemical1102 * Mass Fraction w1m1 [mol/kg](a)Chemical2102 * Mass Fraction w2m2 [mol/kg](a)Chemical3102 * Mass Fraction w3m3 [mol/kg]Chemical4m4 [mol/kg]Solid Phase(s)(b)
50(NH4)2H2P2O70.00.0NH4H2PO440.55.92H2O (a)  pyro-P2O5     59.50.0ortho-P2O52.96A
50(NH4)2H2P2O76.30.53NH4H2PO437.75.85H2O (a)  pyro-P2O5     56.00.53ortho-P2O52.93A
50(NH4)2H2P2O79.10.79NH4H2PO436.45.81H2O (a)  pyro-P2O5     54.50.79ortho-P2O52.90A
50(NH4)2H2P2O716.31.51NH4H2PO432.75.57H2O (a)  pyro-P2O5     51.01.51ortho-P2O52.78A
50(NH4)2H2P2O726.72.70NH4H2PO426.74.98H2O (a)  pyro-P2O5     46.62.72ortho-P2O52.50A
50(NH4)2H2P2O734.83.91NH4H2PO423.24.80H2O (a)  pyro-P2O5     42.03.91ortho-P2O52.40A
50(NH4)2H2P2O740.04.72NH4H2PO420.04.35H2O (a)  pyro-P2O5     40.04.72ortho-P2O52.17A
50(NH4)2H2P2O748.06.29NH4H2PO416.03.86H2O (a)  pyro-P2O5     36.06.29ortho-P2O51.53 (c)B
50(NH4)2H2P2O751.06.64NH4H2PO412.83.07H2O (a)  pyro-P2O5      36.26.65ortho-P2O51.53B
50(NH4)2H2P2O753.66.74NH4H2PO48.92.1H2O (a)  pyro-P2O5     37.56.74ortho-P2O51.03B
50(NH4)2H2P2O761.07.38NH4H2PO40.00.0H2O (a)  pyro-P2O5     39.07.38ortho-P2O50.00B
Table 2. Solubility values for the (NH4)2H2P2O7-NH4H2PO4-H2O system.
t/°CChemical1102 * Mass Fraction w1m1 [mol/kg](a)Chemical2102 * Mass Fraction w2m2 [mol/kg](a)Chemical3102 * Mass Fraction w3m3 [mol/kg]Chemical4m4 [mol/kg]Solid Phase(s)(b)
70(NH4)2H2P2O70.00.0NH4H2PO449.58.52H2O (a) pyro-P2O5  50.50.0ortho-P2O54.26A
70(NH4)2H2P2O77.50.74NH4H2PO445.08.24H2O (a) pyro-P2O5  47.50.74ortho-P2O54.12A
70(NH4)2H2P2O710.81.10NH4H2PO443.08.09H2O (a) pyro-P2O5  46.21.10ortho-P2O54.04A
70(NH4)2H2P2O719.02.08NH4H2PO438.07.68H2O (a) pyro-P2O5  43.02.08ortho-P2O53.84A
70(NH4)2H2P2O731.13.88NH4H2PO431.17.15H2O (a) pyro-P2O5  37.83.88ortho-P2O53.57A
70(NH4)2H2P2O739.05.25NH4H2PO426.06.46H2O (a) pyro-P2O5  35.05.26ortho-P2O53.23A
70(NH4)2H2P2O744.96.47NH4H2PO422.45.95H2O (a) pyro-P2O5  32.76.48ortho-P2O53.00A
70(NH4)2H2P2O752.58.25NH4H2PO417.55.07H2O (a) pyro-P2O5  30.08.25ortho-P2O52.53B
70(NH4)2H2P2O755.58.55NH4H2PO413.93.95H2O (a) pyro-P2O5  30.68.56ortho-P2O51.97B
70(NH4)2H2P2O759.59.17NH4H2PO49.92.8H2O (a) pyro-P2O5  30.69.17ortho-P2O51.40B
70(NH4)2H2P2O767.09.57NH4H2PO40.00.0H2O (a) pyro-P2O5  33.010.02ortho-P2O50.00B
   Table 1  a  These values were calculated by the computer
   Table 1  b  The solid phases are: A=NH4H2PO4: B=(NH4)2H2P2O7.
   Table 1  c  This is an obvious error. The compiler thinks this value should be 1.9.3.
   Table 2  a  These values were calculated by the compiler.
   Table 2  b  The solid phases are: A=NH4H2PO4: B=(NH4)2H2P2O7.

   The visual polythermic method was used. All experimental details are described in Ref (1).

Source and Purity of Materials:
   The only information given is that (NH4)2H2P2O7 was prepared by heating (NH4)4P2O7 to 125 °C.

Estimated Errors:
   Solubility: No information is given.

   1G. A. Chulanova, R. I. Shipyatskaya, and L. S. Mukhina, Zh. Prikl. Khim. (Leningrad) 47, 1637 (1974).