Ammonium dihydrogen phosphate

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Ammonium dihydrogen phosphate
Monoammonium phosphate MAP sample.jpg
Agricultural MAP sample
Names
IUPAC name
Ammonium dihydrogen phosphate
Other names
Monoammonium phosphate
MAP
Identifiers
Jmol-3D images Image
Properties
H6NO4P
NH4H2PO4
Molar mass 115.02 g/mol
Appearance Crystalline white solid
Odor Odorless
Density 1.80 g/cm3
Melting point 190 °C (374 °F; 463 K)
Boiling point Decomposes
40.4 g/100 mL
Solubility Soluble in ethanol
Insoluble in acetone
Thermochemistry
−1445.07 kJ/mol
Hazards
Safety data sheet Fisher Scientific
Lethal dose or concentration (LD, LC):
5750 mg/kg (rat, oral)
Related compounds
Related compounds
Phosphoric acid
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Ammonium dihydrogen phosphate (ADP), more commonly known as monoammonium phosphate (MAP), is an inorganic chemical compound with the formula NH4H2PO4, mainly used as a fertilizer.

Properties

Chemical

MAP will decompose when heated to yield water vapors and leave behind polyphosphoric acid residue.

Physical

MAP is a crystalline white solid, soluble in water and alcohol. It has a density of 1.80 g/cm3.

Availability

Ammonium dihydrogen phosphate is sold as fertilizer, and it's fairly pure, though you can increase it's purity via recrystallization.

It is also available as the main component of dry powder fire extinguishers.

Preparation

Ammonium dihydrogen phosphate can be made by reacting ammonium bicarbonate or ammonium carbonate with phosphoric acid, with the following molar ratio:

NH4HCO3 + H3PO4 → NH4H2PO4 + H2O + CO2
(NH4)2CO3 + 2 H3PO4 → 2 NH4H2PO4 + 2 H2O + 2 CO2

Projects

  • Make piezoelectric crystals

Handling

Safety

MAP is safe to handle and has little toxicity.

Storage

MAP should be stored in closed bottles.

Disposal

MAP can be dumped in the ground or poured down the drain.

References

Relevant Sciencemadness threads