Inorganic · NH₃
A pungent, water-soluble gas — a major fertilizer feedstock and industrial refrigerant. Feedstock for urea and nitric acid; an efficient refrigerant (R-717). Toxic and corrosive to copper alloys.
| Formula | NH₃ |
| CAS number | 7664-41-7 |
| Synonyms | NH3, R-717, azane |
| Molar mass | 17.03 g/mol (Computed from the molecular formula and CODATA atomic weights) |
| Normal boiling point | -33.34 °C (NIST Chemistry WebBook (webbook.nist.gov)) |
Antoine equation (mmHg/°C): log₁₀(P) = 7.3605 − 926.132 / (240.17 + T), valid -83–60 °C. Source: NIST Chemistry WebBook (webbook.nist.gov).
| °C | kPa | bar | mmHg | psia |
|---|---|---|---|---|
| -83.0 | 3.92 | 0.0392 | 29.4 | 0.568 |
| -54.4 | 31.63 | 0.3163 | 237.2 | 4.587 |
| -25.8 | 146.27 | 1.4627 | 1097.1 | 21.215 |
| 2.8 | 471.73 | 4.7173 | 3538.2 | 68.418 |
| 31.4 | 1188.82 | 11.8882 | 8916.9 | 172.423 |
| 60.0 | 2512.15 | 25.1215 | 18842.6 | 364.356 |
Using its Antoine constants (NIST Chemistry WebBook (webbook.nist.gov)), the saturation pressure of ammonia at 25 °C is about 983.57 kPa. Use the calculator above for any temperature within -83–60 °C.
Ammonia boils at -33.34 °C at atmospheric pressure (NIST Chemistry WebBook (webbook.nist.gov)). At that temperature its vapor pressure equals one atmosphere (760 mmHg).
Ammonia (NH₃, CAS 7664-41-7) has a molar mass of 17.03 g/mol.