IUPAC-NIST Solubility Database
NIST Standard Reference Database 106

Glass Ball as Bullet Solubility System: Ammonium dihydrogenphosphate with Ammonium nitrate, Urea nitrate, Urea phosphate and Water

   (1) Ammonium dihydrogenphosphate; NH4H2PO4; [7722-76-1]  NIST Chemistry WebBook for detail
   (2) Ammonium nitrate; NH4NO3; [6484-52-2]  NIST Chemistry WebBook for detail
   (3) Urea nitrate; CO(NH2)2.HNO3; [17687-37-5]  NIST Chemistry WebBook for detail
   (4) Urea phosphate; CO(NH2)2.H3PO4; [4861-19-2]  NIST Chemistry WebBook for detail
   (5) Water; H2O; [7732-18-5]  NIST Chemistry WebBook for detail

Original Measurements:
   Kummel, R.; Fahsl, R., Z. Anorg. Allg. Chem. 1973, 402, 305.


   Concentration = Composition at 20 ºC and 40 ºC.

Prepared By:
   J. Eysseltová

Experimental Data:   (Notes on the Nomenclature)
(Please see footnotes following the table(s).)
Table 1. Composition of invariant points in the NH4H2PO4-NH4NO3-CO(NH2)2.HNO3-CO(NH2)2·H3PO4-H2O system at
t/°CChemical1102 * Mass Fraction w1m1 [mol/kg](a)Chemical2102 * Mass Fraction w2m2 [mol/kg](a)Chemical3102 * Mass Fraction w3m3 [mol/kg](a)Chemical4102 * Mass Fraction w4Solid Phase(s)(b)
20CO(NH2)2.HNO315.263.245CO(NH2)2.H3PO414.922.469NH4H2PO431.597.183H2O38.23A + B + C
40CO(NH2)2.HNO319.536.255CO(NH2)2.H3PO420.735.168NH4H2PO434.3611.77H2O25.38A + B + C
Table 2
t/°CChemical1102 * Mass Fraction w1m1 [mol/kg](a)Chemical2102 * Mass Fraction w2m2 [mol/kg](a)Chemical3102 * Mass Fraction w3m3 [mol/kg](a)Chemical4102 * Mass Fraction w4Solid Phase(s)(b)
20NH4NO351.8920.10CO(NH2)2.HNO37.851.98NH4H2PO48.011.57H2O32.25A + C + D
40NH4NO354.9930.49CO(NH2)2.HNO311.274.07NH4H2PO411.213.15H2O22.53A + C + D
   Table 1  a  The molalities were calculated by the compiler and are expressed as mol kg–1.
   Table 1  b  The solid phases are: A=CO(NH2)2·HNO3; B=CO(NH2)2·H3PO4; C=NH4H2PO4; D=NH4NO3.

   Mixtures of the components were stirred vigorously and allowed to equilibrate for 15 hrs to 25 hrs. The equilibrium was checked by repeated analysis of the liquid phase. PO43– content was determined by precipitation titration with La(NO3)3 using Chromazurol S as indicator; NH4+ was determined, after removal of phosphate ions with the aid of anion exchange resin, by formol tritration. Urea was determined gravimetrically as dixanthedrylurea or after enzyme decomposition as NH3. Nitrate was determined gravimetrically with Nitron. The sum of NH4+ and urea was determined by the Kjeldahl method and the concentration of urea salts was determined by acidimetric titration with a METROHM potentiograph.

Source and Purity of Materials:
   The ammonium salts were recrystallized before use. The urea salts were synthesized from urea and an equivalent amount of the respective acid and recrystallized several times.

Estimated Errors:

   Temperature: No information given.