NH₃
Compound · Base
Ammonia
氨 (氨气/氨水)
Ammonia (氨 (氨气/氨水)), formula NH₃, is a base with a molar mass of 17.03 g/mol (CAS 7664-41-7). Colourless gas with a sharp pungent smell; extremely soluble in water.
Key facts
| Molar mass | 17.03 g/mol |
|---|---|
| Category | Base |
| State at 25°C | Gas |
| CAS | 7664-41-7 |
Structure
H–N(–H)–H
Trigonal pyramidal with a lone pair; polar molecule
Physical properties
| Appearance | Colourless gas with a sharp pungent smell |
|---|---|
| Melting point | −78 °C |
| Boiling point | −33 °C |
| Density | 0.77 g/L (气体) |
| Solubility | Extremely soluble in water |
Key reactions
NH₃ + H₂O ⇌ NH₃·H₂O ⇌ NH₄⁺ + OH⁻
Dissolves in water as a weak base
NH₃ + HCl → NH₄Cl
Reacts with acid to ammonium salt (white smoke)
4NH₃ + 5O₂ →(催化) 4NO + 6H₂O
Catalytic oxidation — first step of nitric-acid manufacture
Main uses
- Nitrogen fertiliser via ammonia synthesis
- Industrial refrigerant
- Cleaning agents and chemical feedstock
Hazard
ModerateToxic and strongly irritating; high levels damage the airways
Constituent elements
Data sources
Molar mass is computed from IUPAC (CIAAW) standard atomic weights; formula, properties and reactions can be verified on PubChem, NIST and Wikipedia. The CAS number is the substance's unique registry identifier. Educational reference only.