Ammonium dihydrogen phosphate


Ammonium dihydrogen phosphate
Ammonium dihydrogen phosphate[1]
Identifiers
CAS number 7722-76-1 YesY
ChemSpider 22812 YesY
Jmol-3D images Image 1
Properties
Molecular formula H6NO4P
Molar mass 115.03 g mol−1
Appearance white tetragonal crystals
Density 1.80 g/cm3
Melting point

190 °C, 463 K, 374 °F

Solubility in water 40.4 g/100 mL
Hazards
NFPA 704
NFPA 704.svg
0
1
0
Thermochemistry
Std enthalpy of
formation
ΔfHo298
-1445.07 kJ/mol
Related compounds
Other anions Ammonium phosphate
Diammonium phosphate
Other cations Monosodium phosphate
Potassium dihydrogen phosphate
 YesY (verify) (what is: YesY/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Ammonium dihydrogen phosphate (ADP), or monoammonium phosphate, NH4H2PO4, is formed when a solution of phosphoric acid is added to ammonia until the solution is distinctly acidic. It crystallizes in tetragonal prisms. Monoammonium phosphate is often used in the blending of dry agricultural fertilizers. It supplies soil with the elements nitrogen and phosphorus in a form which is usable by plants. The compound is also a component of the ABC powder in some dry chemical fire extinguishers. This substance is also supplied in an emerald green or aquamarine crystal growing box kit for children.

Solid monoammonium phosphate show a dissociation pressure of ammonia of 0.05 mmHg at 125°C based on the decomposition reaction as follows:[2]

NH4H2PO4(s) is in equilibrium with NH3(g) + H3PO4(l)

ADP is a widely used crystal in the field of optics due to its birefringence properties. As a result of its tetragonal crystal structure, this material has negative uniaxial optical symmetry with typical refractive indices no=1.522 an ne=1.478 at optical wavelengths.[3]

ADP crystals are piezoelectric which is a property required in some active sonar transducers (the alternative being transducers that use magnetostriction). In the 1950s ADP crystals largely replaced the Quartz and Rochelle Salt crystals in transducers because they are easier to work than Quartz and, unlike Rochelle Salt, are not deliquescent.[4]

References

  1. ^ Lide, David R. (1998). Handbook of Chemistry and Physics (87 ed.). Boca Raton, FL: CRC Press. pp. 4–40. ISBN 0-8493-0594-2. 
  2. ^ John R Van Wazer (1958). Phosphorus And Its Compounds - Volume I: Chemistry. New York: Interscience Publishers, Inc. p. 503. 
  3. ^ Amnon Yariv,Pochi Yeh (1984). Optical Waves in Crystals. Wiley, Inc. 
  4. ^ Willem Hackmann (1984). Seek and Strike: Sonar, Anti-Submarine Warfare and the Royal Navy, 1914–1954. Her Majesty's Stationery Office. ISBN 0-11-290423-8. 

Wikimedia Foundation. 2010.

Look at other dictionaries:

  • ammonium dihydrogen phosphate — amonio dihidrofosfatas statusas T sritis chemija formulė NH₄H₂PO₄ atitikmenys: angl. ammonium biphosphate; ammonium dihydrogen phosphate; ammonium dihydrophosphate; diacid ammonium phosphate rus. аммония дигидрофосфат; аммония первичный кислый… …   Chemijos terminų aiškinamasis žodynas

  • ammonium dihydrogen phosphate — noun see ammonium phosphate …   Useful english dictionary

  • Phosphate monoammonique — Général Nom IUPAC …   Wikipédia en Français

  • Ammonium phosphate — For other uses, see Ammonium phosphate (disambiguation). Ammonium phosphate[1] …   Wikipedia

  • ammonium phosphate — noun : a phosphate of ammonium made by reaction of ammonia and phosphoric acid: as a. : the white crystalline primary phosphate NH4H2PO4 or sometimes a commercial mixture of this with ammonium sulfate, used chiefly as a fertilizer and as a fire… …   Useful english dictionary

  • ammonium biphosphate — amonio dihidrofosfatas statusas T sritis chemija formulė NH₄H₂PO₄ atitikmenys: angl. ammonium biphosphate; ammonium dihydrogen phosphate; ammonium dihydrophosphate; diacid ammonium phosphate rus. аммония дигидрофосфат; аммония первичный кислый… …   Chemijos terminų aiškinamasis žodynas

  • ammonium dihydrophosphate — amonio dihidrofosfatas statusas T sritis chemija formulė NH₄H₂PO₄ atitikmenys: angl. ammonium biphosphate; ammonium dihydrogen phosphate; ammonium dihydrophosphate; diacid ammonium phosphate rus. аммония дигидрофосфат; аммония первичный кислый… …   Chemijos terminų aiškinamasis žodynas

  • Phosphate — Systematic name …   Wikipedia

  • Phosphate — A form of phosphoric acid. Calcium phosphate makes bones and teeth hard. * * * 1. A salt or ester of phosphoric acid. For individual phosphates not listed here, see under the name of the base. 2. The trivalent ion, PO43−. bone p. SYN: tribasic… …   Medical dictionary

  • diacid ammonium phosphate — amonio dihidrofosfatas statusas T sritis chemija formulė NH₄H₂PO₄ atitikmenys: angl. ammonium biphosphate; ammonium dihydrogen phosphate; ammonium dihydrophosphate; diacid ammonium phosphate rus. аммония дигидрофосфат; аммония первичный кислый… …   Chemijos terminų aiškinamasis žodynas