Sulfur

Notable characteristics

It is a Non-métal of yellow aspect pale which can combine with the Hydrogène to give the Sulfure of hydrogen which is a pollutant gas which has an odor characteristic of putrefied eggs. It burns with a non luminous flame which emits an odor particularly suffocating (the Sulfur dioxide SO). Sulfur is insoluble in water but is soluble in (bi-) the Carbon bisulphide (CS). The most common states of oxidation of sulfur are −2, +2, +4 and +6.

In all the states: solid, Liquid and Gas them, sulfur has forms allotropic S. One can show that sulfur Cristal flax is made of rings with 8 members: S.

The Polymère S of Nitrure of sulfur have metal properties although they do not contain any atom Métal lic; this compound also has electric properties and Optique S not very common.

Amorphous sulfur or “plastic” can be produced by fast cooling of crystalline sulfur. The studies by x-rays prove that the amorphous form is made of a helicoid structure with eight sulfur atoms per whorl.

Sulfur can be obtained in two crystalline forms: Octahedral S Orthorhombic S or in prism S Monoclinical S; the orthorhombic form being most stable at the ordinary temperatures.

Applications

Sulfur is employed in many industrial processes such as the sulphuric production of Acid (HSO) for the battery S, the production of gunpowder and the Vulcanization of the rubber. Sulfur is also employed like Fongicide and in the manufacture of phosphatic Engrais . Sulfur is also used in the manufacture of the Allumette S and the fireworks.

The sulphites are employed to bleach the Papier and the dry fruits.

The thiosulfate of Sodium or Ammonium is employed like agent of fixation in Photographie. The salts of Epsom, the Epsom salt, can be employed like Laxatif, additive of bath, Exfoliant or source of Magnésium for the growth of the Plante S.

Biological role

The amino-acids Cystein, Methionine, Homocystéine and Taurine contain sulfur, just as some Enzyme S commun runs, with all the alive cell S.

The bonds disulfide between Polypeptide S play a very important part in the assembly and the structure of the Protéine S.

Some types of Bactérie S employ the Sulfure of hydrogen (HS) instead of water like donor of electron in a process similar to a primitive Photosynthèse.

Sulfur is absorbed ground by the Plante S in the form of ion sulfates.

Inorganic sulfur is present in the centers iron-sulfur of the Métalloprotéine S and sulfur is the ligand site Cu of the oxydase of the Cytochrome C.

History

Sulfur ( çulbâri (enemy of copper) in Sanskrit; sulfur , sulfur or sulpur in Latin) is known since Antiquity. Homère mentioned sulfur like “moving away vermin” with and in -424, a tribe destroyed the walls of a city by burning a mixture of coal, of sulfur and Goudron under its walls.

Dioscoride describes it like an easily reduced yellow body powders some, which burns with a small non luminous flame accompanied by an irritating smoke used by the soldiers to make flee the enemy.

Around the 12th century, the Chinese invented the Gunpowder which is a mixture of Nitrate of potassium (KNO), of carbon and sulfur. The first alchemists gave to sulfur its own alchemical symbol which was a triangle above a cross. By experimentation, these alchemists knew that the mercury could be combined with sulfur. Towards the end of the Years 1770, Antoine Lavoisier helped to convince the scientific community which sulfur was an element and not a compound.

Sources of sulfur

Sulfur is naturally in great quantity, composed with other elements in the form of sulfides (for example: the Pyrite) and of sulfates (for example: the Gypsum). One finds it in free form on the level of the hot sources, the Fumerolle S and more generally in the volcanic gases. Its free form is also present in the form of ore like the Cinabre, the Galène, the Sphalérite and the Stibine.

This element is also in minor amounts in the coal and the Pétrole, which produce sulfur dioxide when they burn. Standards on the Carburant S require more and more that sulfur be extracted from fossile fuels, because the sulfur dioxide combines with water present in the atmosphere (droplets of rain) to produce the acid rains. This extracted sulfur is then refined and represents most of production of sulfur.

It is also extracted along the coast from the Gulf of Mexico, according to the Frash process: steam to 160°C is injected into the sulfur layer, which dissolves it. Compressed air is then injected into the well to make go up sulfur melted on the surface.

For the great quantities, sulfur is transported by sea route on specialized ships called Soufrier S.

Simple: Sulfur Zh-yue: 硫

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