IUPAC-NIST Solubility Database
NIST Standard Reference Database 106

Glass Ball as Bullet Solubility System: Ammonia with Diphosphoric acid and Water

   (1) Ammonia; NH3; [7664-41-7]  NIST Chemistry WebBook for detail
   (2) Diphosphoric acid; H4P2O7; [2466-09-3]  NIST Chemistry WebBook for detail
   (3) Water; H2O; [7732-18-5]  NIST Chemistry WebBook for detail

Original Measurements:
   Farr, T.D.; Fleming, J.D., J. Chem. Eng. Data 1965, 10. 20.


   Concentration = Composition at 273 K and 298 K.

Prepared By:
   J. Eysseltová

Experimental Data:   (Notes on the Nomenclature)
(Please see footnotes following the table(s).)
Solubility in the NH3-H4P2O7-H2O system at 273 K.
pHChemical1102 * Mass Fraction w1Chemical2102 * Mass Fraction w2Chemical3102 * Mass Fraction w3m3 [mol/kg]Chemical4102 * Mass Fraction w4m4 [mol/kg]Chemical5102 * Mass Fraction w5Solid Phase(s)(b)
----N4.83P2O522.59NH3 (a)5.875.24H4P2O7 (a)28.322.42H2O (a)65.80A
4.80N7.66P2O530.74NH3 (a)9.3110.49H4P2O7 (a)38.544.15H2O (a)52.14"
4.97N8.23P2O532.24NH3 (a)10.0011.85H4P2O7 (a)40.424.58H2O (a)49.57"
5.09N8.96P2O534.18NH3 (a)10.8913.82H4P2O7 (a)42.835.20H2O (a)46.28A + B
5.81N9.05P2O531.02NH3 (a)11.0012.89H4P2O7 (a)38.894.36H2O (a)50.10B
----N9.24P2O530.88NH3 (a)11.2313.18H4P2O7 (a)38.724.35H2O (a)50.05"
----N10.04P2O531.42NH3 (a)12.2114.81H4P2O7 (a)39.404.57H2O (a)48.40"
6.50N10.33P2O532.03NH3 (a)12.5615.60H4P2O7 (a)40.164.77H2O (a)47.28"
6.88N9.26P2O527.36NH3 (a)11.2612.14H4P2O7 (a)34.303.54H2O (a)54.44B + D
7.80N7.75P2O520.65NH3 (a)9.448.57H4P2O7 (a)25.892.25H2O (a)64.67D
3.51N6.11P2O528.85NH3 (a)7.437.73H4P2O7 (a)36.173.60H2O (a)56.40A
4.66N8.33P2O535.34NH3 (a)10.1313.05H4P2O7 (a)44.315.46H2O (a)45.56"
4.66N9.52P2O538.89NH3 (a)11.5817.13H4P2O7 (a)48.766.91H2O (a)39.66"
4.84N11.05P2O542.39NH3 (a)13.4423.61H4P2O7 (a)53.158.94H2O (a)33.41B
5.05N10.69P2O540.27NH3 (a)13.0020.90H4P2O7 (a)50.497.77H2O (a)36.51"
5.30N10.49P2O538.52NH3 (a)12.7519.23H4P2O7 (a)48.306.97H2O (a)38.95"
5.75N10.42P2O537.21NH3 (a)12.6718.29H4P2O7 (a)46.656.44H2O (a)40.68"
5.91N10.61P2O536.22NH3 (a)12.9018.17H4P2O7 (a)45.416.12H2O (a)41.69"
6.05N10.61P2O535.81NH3 (a)12.9017.95H4P2O7 (a)44.905.98H2O (a)42.20"
----N11.29P2O535.99NH3 (a)13.7319.59H4P2O7 (a)45.136.16H2O (a)41.15"
6.26N11.55P2O536.60NH3 (a)14.0420.58H4P2O7 (a)45.896.44H2O (a)40.07B + C
6.40N11.14P2O534.93NH3 (a)13.5418.64H4P2O7 (a)43.805.77H2O (a)42.66C
6.43N11.13P2O535.10NH3 (a)13.5318.71H4P2O7 (a)44.015.82H2O (a)42.46"
6.42N11.12P2O535.12NH3 (a)13.5218.70H4P2O7 (a)44.035.83H2O (a)42.45"
6.42N11.05P2O534.62NH3 (a)13.4418.28H4P2O7 (a)43.415.65H2O (a)43.15"
----N10.86P2O533.45NH3 (a)13.2017.28H4P2O7 (a)41.945.25H2O (a)44.86C + D
6.79N10.52P2O531.82NH3 (a)12.7915.87H4P2O7 (a)39.904.74H2O (a)47.31D
7.02N9.79P2O528.63NH3 (a)11.9013.39H4P2O7 (a)35.903.86H2O (a)52.20"
7.35N9.00P2O524.86NH3 (a)10.9411.10H4P2O7 (a)31.173.03H2O (a)57.89"
7.95N8.53P2O522.67NH3 (a)10.379.95H4P2O7 (a)28.422.61H2O (a)61.20"
8.20N8.26P2O521.27NH3 (a)10.049.32H4P2O7 (a)26.672.37H2O (a)63.29"
   Table 1  a  These values were calculated by the compiler.
   Table 2  b  The solid phases are: A=(NH4)2H2P2O7; B=(NH4)3H2P2O7·H2O; C=(NH4)4P2O7; D=(NH4)4P2O7·H2O.

   The complexes, in capped glass tubes, were equilibrated in a cold room or in a water bath. The approach to equilibrium was followed by periodic petrographic and X-ray examination of the solid phases and by analyses of the liquid phase. Phosphorus was determined gravimetrically as quinolinium molybdophosphate1 and nitrogen by distillation of ammonia with NaOH. pH was measured with a glass electrode. One-dimensional paper chromatography2 was used to check the hydrolysis.

Source and Purity of Materials:
   The ammonium pyrophosphates and their solutions were prepared by ammoniation and vacuum evaporation of 0.3 NH4P2O7 that had been prepared by ion exchange from solutions of recrystallized tetrasodium pyrophosphate. All operations were carried out at temperatures below 10 °C. No significant hydrolysis of the pyrophosphate was observed.

Estimated Errors:

   Temperature: The only information given is that the temperature was kept constant as follows: ±0.5 °C; 25 ± 0.02 °C.

   1 C. H. Perrin, J. Assoc. Offic. Agr. Chemists 41, 758 (1958).
   2 E. Karl-Kroupa, Anal. Chem. 28, 1091 (1956).