Diammonium Phosphate - Wikipedia

Diammonium phosphate[1]

Names
IUPAC name diammonium hydrogen phosphate
Other names ammonium monohydrogen phosphate, ammonium hydrogen phosphate, ammonium phosphate dibasic
Identifiers
CAS Number	7783-28-0 Y
3D model (JSmol)	Interactive image
ChEBI	CHEBI:63051
ChemSpider	22946 Y
ECHA InfoCard	100.029.079
E number	E342(ii) (antioxidants, ...)
PubChem CID	24540
UNII	10LGE70FSU Y
CompTox Dashboard (EPA)	DTXSID6029705
InChI InChI=1S/2H3N.H3O4P/c;;1-5(2,3)4/h2*1H3;(H3,1,2,3,4) YKey: MNNHAPBLZZVQHP-UHFFFAOYSA-N Y InChI=1/2H3N.H3O4P/c;;1-5(2,3)4/h2*1H3;(H3,1,2,3,4)/p-1Key: MNNHAPBLZZVQHP-REWHXWOFAG
SMILES [NH4+].[NH4+].OP([O-])([O-])=O
Properties
Chemical formula	(NH4)2HPO4
Molar mass	132.06 g/mol
Appearance	colorless monoclinic crystals
Density	1.619 g/cm3
Melting point	155 °C (311 °F; 428 K) decomposes
Solubility in water	57.5 g/100 mL (10 °C) 106.7 g/100 mL (70 °C)
Solubility	insoluble in alcohol, acetone and liquid ammonia
Refractive index (nD)	1.52
Thermochemistry
Std enthalpy offormation (ΔfH⦵298)	−1566.91 kJ/mol
Hazards
NFPA 704 (fire diamond)	2 0 1
Flash point	Non-flammable
Safety data sheet (SDS)	ICSC 0217
Related compounds
Other anions	Monoammonium phosphateTriammonium phosphate
Other cations	Disodium phosphateDipotassium phosphate
Related compounds	Ammonium nitrateAmmonium sulfate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references

Chemical compound

Diammonium phosphate (DAP; IUPAC name diammonium hydrogen phosphate; chemical formula (NH4)2(HPO4)) is one of a series of water-soluble ammonium phosphate salts that can be produced when ammonia reacts with phosphoric acid.

Solid diammonium phosphate shows a dissociation pressure of ammonia as given by the following expression and equation:[2]

(NH4)2HPO4(s) ⇌ NH3(g) + (NH4)H2PO4(s)

At 100 °C, the dissociation pressure of diammonium phosphate is approximately 5 mmHg.[3]

According to the diammonium phosphate MSDS from CF Industries, Inc., decomposition starts as low as 70 °C: "Hazardous Decomposition Products: Gradually loses ammonia when exposed to air at room temperature. Decomposes to ammonia and monoammonium phosphate at around 70 °C (158 °F). At 155 °C (311 °F), DAP emits phosphorus oxides, nitrogen oxides and ammonia."

Uses

[edit]

DAP is used as a fertilizer.[4] When applied as plant fertilizer, it temporarily increases the soil pH, but over a long term the treated ground becomes more acidic than before, upon nitrification of the ammonium. It is incompatible with alkaline chemicals because its ammonium ion is more likely to convert to ammonia in a high-pH environment. The average pH in solution is 7.5–8.[5] The typical NPK ratio is 18-46-0 (18% N, 46% P2O5, 0% K2O).[5]

DAP can be used as a fire retardant. It lowers the combustion temperature of the material, decreases maximum weight loss rates, and causes an increase in the production of residue or char.[6] These are important effects in fighting wildfires as lowering the pyrolysis temperature and increasing the amount of char formed reduces that amount of available fuel and can lead to the formation of a firebreak.

DAP is also used as a yeast nutrient in winemaking and mead-making; as an additive in some brands of cigarettes purportedly as a nicotine enhancer; to prevent afterglow in matches, in purifying sugar; as a flux for soldering tin, copper, zinc and brass; and to control precipitation of alkali-soluble and acid-insoluble colloidal dyes on wool.[1]

Natural occurrence

[edit]

The compound occurs in the nature as the exceedingly rare mineral phosphammite.[7][8] The related dihydrogen compound occurs as the mineral biphosphammite.[9][8] Both are related to guano deposits.[7][9]

References

[edit]

1. ^ a b Pradyot Patnaik. Handbook of Inorganic Chemicals. McGraw-Hill, 2002, ISBN 0-07-049439-8
2. ^ John R Van Wazer (1958). Phosphorus And Its Compounds - Volume I: Chemistry. New York: Interscience Publishers, Inc. p. 503.
3. ^ McKetta Jr, John J., ed. (1990). Encyclopedia of Chemical Processing and Design (Chemical Processing and Design Encyclopedia). New York: Marcel Dekker, Inc. p. 478. ISBN 0-8247-2485-2.
4. ^ IPNI. "Diammonium Phosphate" (PDF). www.ipni.net. International Plant Nutrition Institute. Archived (PDF) from the original on 24 September 2015. Retrieved 21 July 2014.
5. ^ a b International Plant Nutrition Institute. "Nutrient Source Specifics: Diammonium Phosphate" (PDF). Archived (PDF) from the original on 2012-10-21. Retrieved 2012-12-10.
6. ^ George, C.W.; Susott, R.A. (April 1971). "Effects of Ammonium Phosphate and Sulfate on the Pyrolysis and Combustion of Cellulose". Research Paper INT-90. Intermountain Forest and Range Experiment Station: USDA Forest Service. OL 16022833M.
7. ^ a b "Phosphammite". www.mindat.org. Retrieved 8 November 2020.
8. ^ a b "List of Minerals". www.ima-mineralogy.org. 21 March 2011. Retrieved 8 November 2020.
9. ^ a b "DAP Fertilizer". thesciencepool.com. 3 April 2024. Retrieved 5 April 2024.

External links

[edit]

• International Chemical Safety Card 0217

v t e Ammonium salts
Inorganic salts	monatomic anions NH4F (NH4)2S NH4Cl (NH4)2Se NH4Br NH4I oxyanions NH4NO2 NH4NO3 CaNH4PO4 (NH4)2CO3 (NH4)4UO2(CO3)3 (NH4)HCO3 NH4H2AsO4 NH4BrO3 NH4ClO NH4OCN NH4B5O8 (NH4)3PO4 NH4PH2O2 (NH4)2HPO4 (NH4)H2PO4 NH4IO4 (NH4PO4)n(OH)2 NH4NaHPO4 (NH4)2SO3 (NH4)2SO4 (NH4)Al(SO4)2·12H2O (NH4)2Fe(SO4)2·6H2O NH4Fe(SO4)2·12H2O NH4SO3NH2 (NH4)HSO4 (NH4)2S2O8 (NH4)2S2O3 NH4ClO3 NH4ClO4 (NH4)2Mg(SO4)2 NH4VO3 Nd(NH4)2(NO3)5 (NH4)2CrO4 (NH4)2Cr2O7 NH4MnO4 (NH4)3AsO4 NH4BrO4 (NH4)2MoO4 (NH4)6Mo7O24 (NH4)3Mo12PO40 NH4IO3 (NH4)2Ce(NO3)6 (NH4)8Ce2(SO4)8·4H2O (NH4)10H2W12O42·4H2O NH4ReO4 (NH4)2SeO4 (NH4)2TeO4 other anions NH4BF4 NH4N3 NH4CN NH4[Au(CN)2] (NH4)HF2 (NH4)2SeBr6 (NH4)3AlF6 NH4SbF6 NH4AsF6 (NH4)3CrF6 (NH4)3FeF6 (NH4)3GaF6 (NH4)2GeF6 (NH4)3InF6 NH4NbF6 (NH4)2PtF6 (NH4)2ReF6 (NH4)2SnF6 NH4TaF6 (NH4)2UF6 (NH4)3VF6 (NH4)SiF6 (NH4)HS NH4SCN (NH4)2ZnCl4 (NH4)2MoS4 NH4I3 (NH4)2PtBr6 (NH4)2SnBr6 (NH4)2TeCl6 (NH4)2IrCl6 (NH4)2OsCl6 (NH4)2PtCl6 (NH4)2ReCl6 (NH4)2PdCl6 (NH4)2PbCl6 (NH4)3RhCl6 (NH4)2SeCl6 (NH4)2SnCl6 (NH4)4[Fe(CN)6] (NH4)3VS4 (NH4)2S5 (NH4)4[HgBr6] (NH4)2[PtI6] NH4AuCl4 (NH4)2PdCl4 (NH4)3AsS4 (NH4)2WS4 (NH4)2[PtCl4]
Organic salts	Aluminon Ammonium acetate Ammonium adipate Ammonium alginate Ammonium benzoate Ammonium bituminosulfonate Ammonium butyrate Ammonium carbamate Ammonium caprylate Ammonium cinnamate Ammonium citrate Ammonium diethyl dithiophosphate Ammonium ferric citrate Ammonium formate Ammonium fumarate Ammonium glutamate Ammonium heptadecanoate Ammonium itaconate Ammonium lactate Ammonium lauryl sulfate Ammonium laurate Ammonium malate Ammonium malonate Ammonium mandelate Ammonium myristate Ammonium nicotinate Ammonium nonanoate Ammonium oleate Ammonium oxalate Ammonium picrate Ammonium palmitate Ammonium perfluorononanoate Ammonium picolinate Ammonium propionate Ammonium salicylate Ammonium stearate Ammonium succinate Ammonium tartrate Ammonium thioglycolate Ammonium valerate Cupferron Ferric ammonium oxalate Murexide

v t e Phosphates

H3PO4[HPO4]2−[H2PO4]− He Li3PO4 Be3(PO4)2 BPO4+BO3 C (NH4)3PO4(NH4)2HPO4NH4H2PO4-N O +F Ne Na3PO4Na2HPO4NaH2PO4 Mg3(PO4)2 AlPO4 Si3(PO4)4 P +SO4-S Cl Ar K3PO4K2HPO4KH2PO4 Ca3(PO4)2 ScPO4 Ti VPO4VOPO4 CrPO4 Mn3(PO4)2MnPO4 Fe3(PO4)2FePO4 Co3(PO4)2 Ni3(PO4)2 Cu3(PO4)2 Zn3(PO4)2 GaPO4 Ge As -Se Br Kr Rb3PO4 Sr3(PO4)2 YPO4 Zr3(PO4)4 Nb Mo Tc Ru Rh Pd Ag3PO4 Cd3(PO4)2 InPO4 Sn SbPO4-SbO4 Te I Xe Cs3PO4 Ba3(PO4)2 * LuPO4 Hf Ta W Re Os Ir Pt AuPO4 Hg Tl3PO4 Pb3(PO4)2 BiPO4 Po At Rn Fr Ra ** Lr Rf Db Sg Bh Hs Mt Ds Rg Cn Nh Fl Mc Lv Ts Og   * LaPO4 CePO4 PrPO4 NdPO4 PmPO4 SmPO4 EuPO4 GdPO4 TbPO4 DyPO4 HoPO4 ErPO4 TmPO4 YbPO4 ** AcPO4 Th3(PO4)4 Pa (UO2)3(PO4)2 (NpO2)3(PO4)2 PuPO4(PuO2)3(PO4)2HPuO2PO4 AmPO4 CmPO4 Bk Cf Es Fm Md No