Ammonium Phosphate

Ammonium phosphate is an inorganic compound with the chemical formula of (NH4)3PO4. This compound is the ammonium salt of the ortho-phosphoric acid.


The structure of the chemical compound is shown below.

Structure of Ammonium Phosphate
Structure of chemical compound (Source)

The IUPAC name of this compound is also ammonium phosphate. This compound is highly unstable.

Ammonium Phosphate Preparation

This chemical compouund is manufactured commercially by mixing phosphoric acid with ammonia. Commercial-grade ammonia is usually obtained in crystalline powder form.

Properties of Ammonium Phosphate

Now let us discuss the properties of this compound where we will look at its physical and chemical properties.

Physical Properties

Molecular Formula(NH4)3PO4
Molecular Weight(amu)149.09
Hydrogen Bond Donor Count3
Hydrogen Bond Acceptor Count4
Rotatable Bond Count0
Exact Mass of the compound149.0565
Topological Polar Surface Area89.2 Å2
Heavy Atom Count8
Formal Charge0
Isotope Atom Count0
Is it Canonicalized?Yes
Defined Atom Stereocenter Count0
Undefined Atom Stereocenter Count0
Defined Bond Stereocenter Count0
Undefined Bond Stereocenter Count0
Covalently Bonded Unit Count4
Physical AppearanceWhite Tetrahedral Crystals
Density (g/cm3)1.619
Melting Point (℃)130
Boiling Point (℃)155
Solubility in water(g/100mL)58.0

Chemical Properties

The compound readily undergoes decomposition to give phosphoric acid and ammonia.

(NH4)3PO4 → 3NH3 + H3PO4

It readily reacts with lead nitrate(Pb(NO3)4) to give ammonium nitrate(NH4NO3) and lead phosphate(Pb3(PO4)4).

4(NH4)3PO4 + 3Pb(NO3)4 → Pb3(PO4)4 + 12NH4NO3


Exposure to this compound may cause skin and eye irritation.


  • The compound holds a generic name for a variety of fertilizer materials.
  • It finds an important application as a fertilizer.
  • The inorganic compound is used as a component of intumescent paints and mastics.
  • It is also used as a plant revitalizer.


What is the formula for ammonium phosphate?

The chemical formula of the compound is (NH4)3PO4.

What is the molar mass of ammonium phosphate?

The molar mass of the compound is 149.09amu.

What is ammonium phosphate used for?

It is used as a fertilizer, and also as a flame retardant in thermoplastic compositions.

More on Inorganic Compounds

Sodium Dichromate (Na2Cr2O7)Sodium Potassium Tartrate (C4H4O6KNa.4H2O)
Mohr’s Salt (Fe(SO4)(NH4)2(SO4)(H2O)6)Lead Nitrate Pb(NO3)2
Sodium Sulfate (Na2SO4)Ammonium Bicarbonate ((NH4)HCO3)
Scroll to Top
Scroll to Top