chlorine

• Description
• General information
• Physical data
• Radii
• Electronegativities
• Solid state structure
• Temperatures
• Enthalpies
• Ionization Enthalpies
• Isotopes
• Further information

Description

Chlorine is a greenish yellow gas which combines directly with nearly all elements. Chlorine is a respiratory irritant. The gas irritates the mucous membranes and the liquid burns the skin. As little as 3.5 ppm can be detected as an odour, and 1000 ppm is likely to be fatal after a few deep breaths. It was used as a war gas in 1915. It is not found in a free state in nature, but is found commonly as NaCl (solid or seawater).

General information

Discoveror: Carl William Scheele
Date discovered: 1774
Discovered at: Sweden
Meaning of name: From the Greek word "chloros" meaning "pale green"

Physical data

Standard state: gas at 298 K
Colour: yellowish green
Density of solid at ambient temperature/kg m^-3: no data
Molar volume/cm³: 17.39

Radii /pm

Atomic: 79
Covalent (single bond):
Pauling radius for the ion [Cl]^-: 181

Valence shell orbital radius maxima (R_max)

orbital	s	p	d	f
radius	68.2	76.2	no data	no data

Electronegativities

Both values are quoted on the Pauling scale.

Pauling: 3.16
Allred Rochow: 2.83

Crystal Structure

structure: orthorhombic

The following CrystalMaker image represents the solid state structure. For most elements, the most stable allotrope is illustrated. Try WebElements version 2 for interactive virtual reality and CHIME images.

Temperatures (/K)

melting point: 171.6
boiling point: 239.11

Enthalpies /kJ mol^-1

fusion: 6.41
vaporization: 20.4

single bond enthalpies:

Cl-F	Cl-Cl	Cl-Br	Cl-I	Cl-Cl
142	240	216	208	242.580

Ionization enthalpies /kJ mol^-1

Number	Enthalpy
1st	1251.1
2nd	2297
3rd	3822
4th	5158
5th	6540
6th	9362
7th	11020
8th	33610

Isotopes

This section gives some data for naturally occurring isotopes.

Nominal mass	Accurate mass	% natural abundance
35Cl	34.968852721 (69)	75.77 (5)
37Cl	36.96590262 (11)	24.23 (5)

Further Information

• Additional information about WebElements 1.2.2
• This is a licensed copy (here is the full list) of WebElements 1.2.2 and contains a subset of the material contained within the main version of WebElements (version 2)
• For further information please try WebElements version 2
• Sheffield Chemdex: perhaps the largest internet chemistry directory
• Sheffield Chemputer: interactive chemistry calculators on the WWW