Ammonium dihydrogen phosphate

Ammonium dihydrogen phosphate

Agricultural MAP sample
Names
IUPAC name Ammonium dihydrogen phosphate
Other names Monoammonium phosphate MAP
Identifiers
Jmol-3D images	Image
SMILES [O-]P(=O)(O)O.[NH4+]
Properties
Chemical formula	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
Solubility in water	40.4 g/100 mL
Solubility	Soluble in ethanol Insoluble in acetone
Thermochemistry
Std enthalpy of formation (ΔfHo298)	−1445.07 kJ/mol
Hazards
Safety data sheet	Fisher Scientific
Lethal dose or concentration (LD, LC):
LD50 (Median dose)	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

Physical

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

Availability

Ammonium dihydrogen phosphate is sold as fertilizer, and it's fairly pure.

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

• Phosphate, hydrogen phosphate or dihydrogen phosphate?