Sulfur, also sometimes known as sulfur in British English, is a chemical element with atomic number 16 and the letter S. Sulfur atoms normally combine to form cyclic octatomic molecules with the chemical formula S8. At room temperature, elemental sulfur is a bright yellow crystalline solid.
By mass, sulfur is the tenth most common element in the universe and the fifth most common on Earth. Although pure, natural sulfur can occasionally be found, it is most commonly found on Earth as the sulphide and sulfate minerals. Sulfur was well known in the past because of its abundant natural form; been cited for their purposes in ancient China, Egypt, Greece, and India. Sulfur is also known as brimstone, meaning "flaming stone" in literature and history. As a result of cleaning sulfur-containing impurities from natural gas and oil, almost all elemental sulfur produced today is now produced. The creation of sulfuric acid for sulfate and phosphate fertilizers as well as other chemical processes is the primary economic use of the element. Matches, pesticides, and fungicides all contain sulfur.
Organosulfur compounds, common in sulfur compounds, are responsible for fragrant natural gas, skunk, grapefruit, and garlic odors. The distinctive smell of rotting eggs and other biological processes is caused by hydrogen sulfide.
All life requires sulfur, but it almost invariably takes the form of metal sulfides or organosulfur compounds. Organosulfur compounds are essential for life and include amino acids and the vitamins biotin and thiamine. Various cofactors such as glutathione and iron-sulfur proteins also contain sulfur. Among other things, the protein keratin, found in the outer skin, hair and feathers, is mechanically strengthened and insoluble by disulfides and SS bonds. Sulfur is an essential macronutrient for all living things and is one of the essential chemical components required for metabolic activity.
What are the Physical Properties of Sulfur?
Numerous polyatomic compounds are formed by sulfur. The allotrope of sulfur known as cyclo-S8 is octasulfide. Cyclo-S8 has a dipole moment of 0 D and a point group D4d. Octasulfide is an odorless, soft, bright yellow solid; but impure specimens smell like matches. It sublimes at 20-50 °C, melts at 115,21 °C and boils at 444,6 °C.
Below its melting point, at 95,2 °C, it transforms into the cyclo-octasulfide-polymorph. The intermolecular connections change with this phase change, but the structure of the S8 ring remains essentially constant.
Octasulfide undergoes a second allotrope change, transforming from -octasulfur to -sulfur between melting and boiling temperatures. This change is once again followed by a decrease in density, but an increase in viscosity due to the formation of polymers. Viscosity decreases as depolymerization occurs at higher temperatures. Above 200 °C, molten sulfur takes on a dark red color. Depending on the allotrope, sulfur has a density of about 2 g/cm3; stable allotropes are all excellent electrical insulators.
Unlike other non-polar organic solvents such as benzene and toluene, sulfur is soluble in carbon disulfide but insoluble in water.
Günceleme: 25/01/2023 11:38