 Discovery Information
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| Who: Karl Wilhelm Scheele |
| When: 1774 |
| Where: Sweden |
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| Name Origin
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| Greek: khloros (green). |
| "Chlorine" in different languages. |
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| Sources
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| Never found in free form in nature. Salt (sodium chloride, NaCl) is its most common compound. Chlorides make up much of the salt dissolved in the Earth's oceans - about 1.9% of the mass of seawater is chloride ions.
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| Abundance
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| Universe: 1 ppm (by weight) |
| Sun: 8 ppm (by weight) |
| Carbonaceous meteorite: 380 ppm |
| Earth's Crust: 130 ppm |
| Seawater: 18000 ppm |
| Human: |
| 1.2 x 106 ppb by weight
|
| 2.1 x 105 ppb by atoms
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| Uses
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| Used widely in paper product production, antiseptic, dyestuffs, food, insecticides, paints, petroleum products, plastics,
medicines, textiles, solvents, and many other consumer products.
|
| Chlorine is an important chemical in some processes of water purification, disinfectants and in bleaches and chlorofluorocarbons
(CFC).
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| History
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| Chlorine was discovered in 1774 by Swedish chemist Karl Wilhelm Scheele, who called it dephlogisticated muriatic acid and mistakenly thought it contained oxygen. Chlorine was given its current name in 1810 by Sir Humphry Davy, who insisted that it was in fact an element.
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| Chlorine gas, also known as bertholite, was first used as a weapon in World War I by Germany on April 22, 1915 in the Second
Battle of Ypres. As described by the soldiers it had a distinctive smell of a mixture between pepper and pineapple. It also
tasted metallic and stung the back of the throat and chest. It was pioneered by a German scientist later to be a Nobel laureate,
Fritz Haber. It is alleged that his role in the use of chlorine as a deadly weapon drove his wife to suicide. After its first
use, it was utilized by both sides as a chemical weapon.
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| Notes
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| The pure chemical element has the physical form of a diatomic yellow-green gas, Cl2. Chlorine combines readily with nearly all other elements. Chlorine is about two and a half times as heavy as air.
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| Hazards
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| Chlorine irritates respiratory systems especially in children and the elderly. In its gaseous state it irritates mucous membranes
and in its liquid state it burns skin. As little as 3.5 ppm (parts per million) can be detected as an odour, and 1000 ppm
is likely to be fatal after a few deep breaths.
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| Toxic fumes may be produced when bleach is mixed with urine, ammonia (NH3), hydrochloric acid (HCl), or another cleaning product. These fumes consist of a mixture of chlorine gas, chloramine and nitrogen trichloride; therefore these combinations should be avoided.
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| Over 2000 naturally-occurring organic chlorine compounds are known. |
| Chlorine is very toxic to aquatic organisms. |
