Diammonium phosphate

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Diammonium phosphate[1]
Diammonium phosphate.png
Identifiers
CAS number 7783-28-0 Yes check.svgY
PubChem 24540
Properties
Molecular formula (NH4)2HPO4
Molar mass 132.07 g/mol
Appearance white powder
Density 1.619 g/cm3
Melting point

155 ºC decomp.

Solubility in water 57.5 g/100 mL (10 ºC)
106.7 g/100 mL (100 °C)
Solubility insoluble in alcohol, acetone and liquid ammonia
Refractive index (nD) 1.52
Hazards
MSDS ICSC 0217
EU Index Not listed
Flash point Non-flammable
Related compounds
Other anions Monoammonium phosphate
Triammonium phosphate
Other cations Disodium phosphate
Dipotassium phosphate
Related compounds Ammonium nitrate
Ammonium sulfate
 Yes check.svgY (what is this?)  (verify)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

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

[edit] Uses

DAP is used as a fertilizer. When applied as plant food, 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.

DAP can be used 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.[2] 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. It is the largest component of some popular commercial firefighting products.[3]

DAP is also used as a yeast nutrient in winemaking and brewing mead; 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]

[edit] External links

[edit] References

  1. ^ a b Pradyot Patnaik. Handbook of Inorganic Chemicals. McGraw-Hill, 2002, ISBN 0070494398
  2. ^ 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), http://openlibrary.org/b/OL16022833M/Effects_of_ammonium_phosphate_and_sulfate_on_the_pyrolysis_and_combustion_of_cellulose 
  3. ^ Phos-Chek MSDS, Phos-Chek website