Monoammonium phosphate
General Product Information
| Article | Monoammonium phosphate |
| Synonyms | ADP, Ammonium dihydrogen phosphate, MAP, Monoammonium phosphate |
| CAS No. | 7722-76-1 |
| EEG No. | – |
| EINECS No. | 231-764-5 |
| IMO | – |
| Tariff Code | 31054000 |
| UN No. | – |
| VLG/ADR | – |
Description
Monoammonium phosphate (MAP) is an inorganic salt. It is an important source of nitrogen (N) and phosphorus (P), essential for plant growth. MAP is often used in water-soluble fertilizers and is suitable for application through irrigation systems.
Characteristics
- Odor: Odorless.
- Hygroscopic: Yes.
- Color: White.
- Grade: Technical.
- Solubility: Highly soluble in water.
- Shape: crystalline grains.
Physical & Chemical Properties
| Chemical Structure | NH4H2PO4 |
| Molar Weight | 115.03 g/mol |
| Melting Point | Approx. 190 °C (decomposes). |
| Boiling Point | Approx. 158°C |
| Density | Approx. 1.8 g/cm³. |
| Refractive Index | – |
| pH | 4.2 – 4.7 (on 1% solution) |
Applications
Monoammonium phosphate is applied in various ways, for instance:
1. Agriculture
Monoammonium phosphate is a common component in compound fertilizers. Its combination of nitrogen (N) and phosphorus (P) makes it ideal for use during the early growing season of crops, when root development is crucial. MAP is applied both in dry form and dissolved in irrigation systems (fertigation).
2. Fire Extinguishers
MAP is a major component of dry powder fire extinguishers (type ABC). It reacts with combustible materials and suppresses flames by forming an insulating layer.
3. Other Industrial Applications
MAP is occasionally used as a reagent in laboratories, as a pH buffer and in fermentation processes. In coatings and surface treatments, it can play a role as a phosphating agent.
Interessing Links
- CAS Common Chemistry – Ammonium dihydrogen phosphate
- European Chemicals Agency (ECHA) – For chemical information and regulations.
- PubChem – Ammonium phosphate, monobasic – Chemical information by the National Library of Medicine of the National Center for Biotechnology Information (NIH-NCBI).
- Wikipedia – Ammoniumdiwaterstoffosfaat