Ammonium Phosphate

Ammonium phosphate is an inorganic compound with the formula (NH 4 ) 3 PO 4 It is the ammonium salt of orthophosphoric acid . A related “double salt” , NH4 ) 3po4 . (NH4 ) 2HPO4 is also recognized but has impractical use Both triammonium salts evolve ammonia. In contrast to the volatile nature of triammonium salts, diammonium phosphate ( NH4 ) 2HPO4 and monoammonium salts (NH) 4 ) H 2 PO 4 are stable materials that are commonly used as fertilizers to provide fixed nitrogen and phosphorus to plants.

Preparation of triammonium phosphate

Triammonium phosphate can be prepared in the laboratory by treating 85% phosphoric acid with a 30% ammonia solution: 

3 PO 4 + 3 NH 3 → (NH 4 ) 3 PO 4

(NH4 ) 3PO4 is a colorless , crystalline solid The solid, which has the smell of ammonia, is readily soluble in water. The salt diammonium hydrogen phosphate (NH 4 ) 2 is converted to HPO 4 .

Ammonium phosphate is an inorganic substance that is produced by reacting ammonia (NH3) with phosphoric acid (H3PO4). The result is a water-soluble salt for the agricultural sector. Its chemical structure includes a group phosphate (H2PO4) and ammonium (NH4). The phosphate group consists of a phosphorus core (P) that binds an oxygen with a double bond, two hydroxides (OH) and an oxygen with a single bond. In turn, this latter oxygen binds to the ammonium, thus forming the entire molecule of ammonium phosphate. Its formula is shown as (NH4) 3PO4.

In nature it occurs in crystals. It is a product that is produced on a large scale economically.

Main characteristics

It occurs in nature as white crystals in the form of tetragonal prisms, or as a bright white powder. 

In fertilizers it comes in granular form or in powder form. It does not have a specific smell.

Ammonium phosphate is normally a stable substance, so you don’t need to pay much attention to whether you will react with any of the agents.

Unlike other substances, it does not represent a hazard to contact. However, it is important to consult a doctor in case of ingestion or irritation.


It is a water soluble compound.

– Its density is 1800 kg / m 3.

– Its molecular weight is 115 g / mol.

– It is insoluble in acetone.

Its pH is slightly acidic. It enters the range of 4 to 4.5.


The main use given to ammonium phosphate is as a fertilizer. Plants require minerals and nutrients that they obtain from the earth in order to grow, develop and produce.

These include nitrogen and phosphorus. Because ammoniumphosphate is soluble in water, plants absorb it very easily from the ground.

Ammoniumphosphate also has a fundamental role in plant photosynthesis, respiration and energy management.

On the other hand, this compound has been researched for use as a hydrogen storage cell in fuel cells.

The tendency to look for efficient technologies has led to a variety of materials being tested, but many are very expensive. Ammonium phosphate is very cheap, so it can represent a great alternative. Some companies use it as a fire extinguisher.

What is the use of ammonium phosphate?

Ammonium phosphate is used as an ingredient in some fertilizers as a high source of elemental nitrogen. It is also used as a flame retardant in thermoplastic compositions.

How is ammonium phosphate prepared?

Triammonium phosphate can be prepared in the laboratory by treating 85% phosphoric acid with a 30% ammonia solution: H 3 PO 4 + 3 NH 3 → (NH 4 ) 3 PO. (NH4)3PO4 is a colorless, crystalline solid. The solid, which has the smell of ammonia, is readily soluble in water.

Is ammonium phosphate a salt?

Ammonium phosphate is a salt of ammonia and phosphoric acid. With a chemical formula of (NH4)3PO4, ammoniumphosphate is found as a crystalline powder, and is soluble in water.

Where does ammonium phosphate come from?

Ammonium phosphate, a highly effective fertilizer, is usually manufactured by the dihydrate process, dilute phosphoric acid concentration, neutralization with ammonia, and granulation and drying of ammoniumphosphate solution (APPAC).