Oxygen
Main page |
| Other names/abbreviations: | O |
| Element no: | 8 |
| Element group: | 16 (IUPAC) VI A (American labelling) VI B (European labelling) Chalcogens |
| Element type: | Nonmetals |
| CAS-Number: | 7782-44-7 |
| EINECS-Number: | 231-956-9 |
Safety
Symbol: OR-phrases: 8
S-phrases: 17
Physical properties
Appearance | ||
| Physical state @ 20°C: | Gas [1] | |
| Color: | O2: Gas: Colorless [1]. Liquid: Pale blue O3: Gas: bluish. Liquid: bluish-black. Solid: violet-black | |
| Odor: | Almost odourless [1] | |
Bulk properties | ||
| Molecular weight (g/mol): | 15.9994 | |
| Melting point (°C): | -218.79 (O2) [2] | |
| Boiling point (°C): | -182.95 (O2) [2] | |
Optical properties | ||
| Refractive index: | O3 (l): 1.2226 [2] | |
Thermodynamic properties | ||
| ΔfH°gas (kJ/mol): | 249.2 (monoatomic) [2] 0.0 (O2) [2] 142.7 (O3) [2] | |
| ΔH°fusion (kJ/mol): | 0.44 (O2) [2] | |
| ΔH°vaporization (kJ/mol): | 3.41 (per mole O atoms) | |
| S°gas (J/K·mol): | 161.1 (monoatomic) [2] 205.2 (O2) [2] 238.9 (O3) [2] | |
| ΔfG°gas (kJ/mol): | 231.7 (monoatomic) [2] 163.2 (O3) [2] | |
| Cp (gas) (J/K·mol): | 21.9 (monoatomic, 25 °C) [2] 29.378 (O2, 25 °C) [2] 39.2 (O3, 25 °C) [2] | |
| Critical temperature (°C): | -118.56 [2] | |
Electronic properties | ||
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Electron configuration: | 1s2-2s2-2p4 |
References
1: Merck. ChemDAT The Merck Chemical Database Ver. 1.1.52: CRC Handbook of Chemistry and Physics
75th edition (1994) Edited by Lide,D.R. , CRC Press Inc. Boca Raton, USA
© Michael Pilgaard
Created: October 4, 2008
Last update: October 9, 2008