Chlorine (gas phase) is the result of combining two chlorine Cl atoms, or the formula Cl2.
Molecular weight: 70.906 g mol-1.

Chemical compound of the family of halogens, chlorine is a yellowish-green gas with suffocating smell very unpleasant and it is extremely toxic.
Chlorine has the highest electron affinity and the fourth highest electronegativity of all the reactive elements. For this reason, chlorine is a strong oxidizing agent. Free chlorine is rare on Earth, and is usually a result of direct or indirect oxidation by oxygen.

The high oxidizing potential of elemental chlorine led commercially to free chlorine's bleaching and disinfectant uses, as well as its many uses of an essential reagent in the chemical industry. Chlorine is used in the manufacture of a wide range of consumer products, about two-thirds of them organic chemicals such as polyvinyl chloride, as well as many intermediates for production of plastics and other end products which do not contain the element. As a common disinfectant, elemental chlorine and chlorine-generating compounds are used more directly in swimming pools to keep them clean and sanitary.

non-flammable gas (but supports combustion in the air).
It is a heavier-than-air gas = 3.2 kg m3-1 (0 °C, 101.325 kPa).
Boiling point = -34.04 °C (239.11 K).
Liquid density at b.p. = 1.5625 g·cm3.
Melting point = -101.5 °C (171.6 K).
Critical point = 416.9 K, 7.991 MPa.
Triple Point is located at T = - 101.00 ° C (172 K) and P = 14 hPa (0.014 bar)
Heat of fusion (Cl2) = 6.406 kJ·mol-1.
Heat of vaporization (Cl2) = 20.41 kJ·mol-1.

Chlorine gas is normally carried in the liquid state, in pressurized steel cylinders.

Chlorine phase diagram:

(Sources : Air Liquide)

Some features::

Standard products used for the production of drinking water : bulletin officiel - Chlore : NF EN 937.


Health effects of the free element and hazards :

(Source : INERIS - 03DR002.doc/Septembre2003)

Link (Canadian Centre for Occupational Health and Safety).

> Sources (link) : BELGOCHLOR (BelgoChlor, Diamant Building, Bd A.Reyers 80, 1030 Bruxelles)

Download Technical MSDS AL (pdf files > over there ).

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