|
|
Oxidation & Electrons | Appearance & Characteristics Reactions | Compounds | Radius | Conductivity Abundance & Isotopes 
Chlorine In Test Tube |
General:
| Name: Chlorine | Symbol: Cl |
| Type: Halogen | Atomic weight: 35.453 |
| Density @ 293 K: 0.003214 g/cm3 | Atomic volume: 22.7 cm3/mol |
| Discovered: Chlorine was produced first in 1774 by Carl Wilhelm Scheele, who observed the greenish-yellow gas released by the reaction of pyrolusite (manganese dioxide) with the substance we now call hydrochloric acid. Scheele mistakenly thought the resulting gas contained oxygen. In 1810, Sir Humphry Davy confirmed this gas was an element, not a compound. He named it chlorine, from the Greek word 'chloros', meaning pale green. | |
States
| State (s, l, g): gas | |
| Melting point: 172 K (-101 oC) | Boiling point: 239 K (-34 oC) |
Energies
| Specific heat capacity: 0.48 J g-1 K-1 | Heat of atomization: 122 kJ mol-1 |
| Heat of fusion: 6.406 kJ mol-1 of Cl2 | Heat of vaporization (sublimation): 20.41 kJ mol-1 of Cl2 |
| 1st ionization energy: 1251.1 kJ mol-1 | 2nd ionization energy: 2297.3 kJ mol-1 |
| 3rd ionization energy: 3821.8 kJ mol-1 | Electron affinity: 349 kJ mol-1 |
Oxidation & Electrons
| Shells: 2,8,7 | Electron configuration: [Ne] 3s2 3p5 |
| Minimum oxidation number: -1 | Maximum oxidation number: 7 |
| Min. common oxidation no.: -1 | Max. common oxidation no.: 7 |
| Electronegativity (Pauling Scale): 3.16 | Polarizability volume: 2.2 Å3 |
Appearance & Characteristics
| Structure: layers of Cl2 | Color: greenish-yellow |
| Harmful effects: Chlorine is a toxic gas that irritates the skin, the eyes and the respiratory system. | Hardness: mohs |
| Characteristics: Chlorine is a greenish-yellow, diatomic, dense gas with a sharp smell (the smell of bleach). It is not found free in nature as it combines readily with nearly all other elements. It occurs in nature mainly as common salt (NaCl), carnallite [ KMgCl2.6(H20) ], and sylvite (KCl). In its liquid and solid form it is a powerful bleaching, oxidizing and disinfecting agent. | |
| Uses: Chlorine is used for producing safe drinking water. Chlorinated compounds are used mostly for sanitation, pulp bleaching, disinfectants, and textile processing. Chlorine is also used for the manufacture of chlorates and it is important in organic chemistry, forming compounds such as chloroform, carbon tetrachloride, polyvinyl chloride, and synthetic rubber. Other uses of chlorine compounds include dyestuffs, petroleum products, medicines, antiseptics, insecticides, foodstuffs, solvents, paints and plastics. | |
Reactions
| Reaction with air: none | Reaction with 6 M HCl: mild, ⇒ HOCl, Cl- |
| Reaction with 15 M HNO3: mild, ⇒ HClOx, NOxCl, NOx | Reaction with 6 M NaOH: mild, ⇒ OCl-, Cl- |
Compounds
| Oxide(s): Cl2O, ClO2, Cl2O7 | Chloride(s): Cl2 |
| Hydride(s): HCl |
Radius
| Atomic radius: 100 pm | Ionic radius (1+ ion): pm |
| Ionic radius (2+ ion): pm | Ionic radius (3+ ion): pm |
| Ionic radius (2- ion): pm | Ionic radius (1- ion): 167 pm |
Conductivity
| Thermal conductivity: 0.0089 W m-1 K-1 | Electrical conductivity: S cm-1 |
Abundance & Isotopes
| Abundance earth's crust: 170 ppm by weight, 100 ppm by moles | |
| Abundance solar system: 8 ppm by weight, 0.3 ppm by moles | |
| Cost, pure: 0.15 $/100g | |
| Cost, bulk: $/100g | |
| Source: Chlorine gas is produced commercially by the electrolysis of sodium chloride (NaCl) from seawater or brine from salt mines. | |
| Isotopes: Chlorine has 16 isotopes whose half-lives are known, with mass numbers 31 to 46. Of these, two are stable: 35Cl and 37Cl. | |
