Diammonium phosphate
<templatestyles src="Chembox/styles.css"/>
Template:Chembox image cellTemplate:Chembox AllOtherNamesTemplate:Chembox headerbarTemplate:Chembox IndexlistTemplate:Chembox JmolTemplate:Chembox ChEMBLTemplate:Chembox ECHATemplate:Chembox E numberTemplate:Chembox IUPHAR ligandTemplate:Chembox UNIITemplate:Chembox CompToxTemplate:Chembox headerbarTemplate:Chembox SolubilityInWaterTemplate:Chembox headerbarTemplate:Chembox headerbarTemplate:Chembox SDSTemplate:Chembox headerbarTemplate:Chembox Datapage checkTemplate:Chembox Footer| Template:Longitem | Template:Unbulleted list |
| ChEBI | Template:Unbulleted list |
| ChemSpider | Template:Unbulleted list |
| DrugBank | Template:Unbulleted list |
| EC Number | Template:Unbulleted list |
| KEGG | Template:Unbulleted list |
| Template:Longitem | Template:Unbulleted list |
| RTECS number | Template:Unbulleted list |
| Script error: No such module "collapsible list". | |
| Script error: No such module "collapsible list". | |
| Template:Longitem | (NH4)2HPO4 |
| Molar mass | 132.06 g/mol |
| Appearance | colorless monoclinic crystals |
| Density | 1.619 g/cm3 |
| Melting point | Template:Chembox CalcTemperatures |
| Solubility | insoluble in alcohol, acetone and liquid ammonia |
| Template:Longitem | 1.52 |
| Template:Longitem | −1566.91 kJ/mol |
| NFPA 704 (fire diamond) | Template:NFPA 704 diamond |
| Flash point | Template:Chembox CalcTemperatures |
| Template:Longitem | Monoammonium phosphate Triammonium phosphate |
| Template:Longitem | Disodium phosphate Dipotassium phosphate |
| Template:Longitem | Ammonium nitrate Ammonium sulfate |
Template:Chembox Footer/trackingScript error: No such module "TemplatePar".Template:Short description
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]
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
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 formulation 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
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
<templatestyles src="Reflist/styles.css" />
- ↑ a b Pradyot Patnaik. Handbook of Inorganic Chemicals. McGraw-Hill, 2002, Template:ISBN
- ↑ Script error: No such module "citation/CS1".
- ↑ Script error: No such module "citation/CS1".
- ↑ Script error: No such module "citation/CS1".
- ↑ a b Script error: No such module "citation/CS1".
- ↑ Script error: No such module "Citation/CS1".
- ↑ a b Script error: No such module "citation/CS1".
- ↑ a b Script error: No such module "citation/CS1".
- ↑ a b Script error: No such module "citation/CS1".
Script error: No such module "Check for unknown parameters".