Chlorine
Main page |
| Other names/abbreviations: | Cl |
| Element no: | 17 |
| Element group: | 17 (IUPAC) VII A (American labelling) VII B (European labelling) Halogens |
| Element type: | Nonmetals |
| CAS-Number: | 7782-50-5 |
| EINECS-Number: | 231-959-5 |
Chemical properties
Reaction of chlorine with metals/metal ionsCd reacts directly with Cl2 in aqueous solution [4].
Cd (s) + Cl2 (aq)
Cd2+ (aq) + 2 Cl- (aq)Solubility
Water: 14.6 g/L (1013 hPa , 0 °C) [3]
7.3 g/L (20 °C) [3]
Safety
Symbol: T, NR-phrases: 23-36/37/38-50
S-phrases: 9-45-61
Physical properties
Appearance | ||
| Physical state @ 20°C: | Gas [1] | |
| Color: | Gas: Greenish-yellow [1] Liquid: Yellow [3] | |
| Odor: | Pungent [3] | |
Bulk properties | ||
| Molecular weight (g/mol): | 35.4527 [1] | |
| Melting point (°C): | -101.5 [2] | |
| Boiling point (°C): | -34.04 [2] | |
| Density (g/cm3): | 1.56 (Liquid, 1008 hPa , -35 °C) [3] 1.41 (Liquid, 6955 hPa , 20 °C) [3] | |
| Relative vapour density (g/cm3): | 2.49 (0 °C) [3] | |
Optical properties | ||
| Refractive index: | 1.000768 (g) [2] 1.367 (l) [2] | |
Thermodynamic properties | ||
| ΔfH°gas (kJ/mol): | 121.0 (monoatomic) [3] 0.0 (Cl2) [3] | |
| ΔH°fusion (kJ/mol): | 6.40 (Cl2) [3] | |
| ΔH°vaporization (kJ/mol): | 10.2 (per mole Cl atoms) | |
| S°gas (J/K·mol): | 165.2 (monoatomic) [3] 223.1 (Cl2) [3] | |
| ΔfG°gas (kJ/mol): | 105.3 (monoatomic) [3] | |
| Cp (gas) (J/K·mol): | 21.8 (monoatomic, 25 °C) [3] 33.949 (Cl2, 25 °C) [3] | |
| Critical temperature (°C): | 143.8 [2] | |
Electronic properties | ||
 |
Electron configuration: | 1s2-2s2-2p6-3s2-3p5 |
| Ionic radius (Å): | Cl(-I) 1.81 (coordination number 6) [2] | |
Misc. | ||
| Vapour pressure (Pa): | 365300 (0 °C) [3] 680000 (20 °C) [3] 1340000 (50 °C) [3] | |
History
DiscoveryChlorine was discovered in 1774 by Carl Wilhelm Scheele, who thought it wasn't an element but something containing oxygen. Sir Humphry Davy showed that chlorine is an element in 1810 and became to one to name the element [2].
Origin of name
From Greek "chloros" meaning "Greenish yellow" [2].
References
1: Greenwood,N.N., Earnshaw,A. Chemistry of the elements2nd edition (1997) Edited by Greenwood,N.N., Earnshaw,A. pp. 1-1340, Butterworth-Heinemann. Oxford. Great Britain
2: CRC Handbook of Chemistry and Physics
75th edition (1994) Edited by Lide,D.R. , CRC Press Inc. Boca Raton, USA
3: Merck. ChemDAT The Merck Chemical Database Ver. 1.1.5
4: Gmelin Handbuch der anorganischen Chemie Erg. 33 (1958)
© Michael Pilgaard
Created: September 25, 2008
Last update: October 10, 2008