Element description
S is a light yellow crystal. There are two forms of elemental sulfur and combined sulfur. There are several allotropes of elemental sulfur. It is mainly rhombic sulfur (S8), with a density of 2.069g/cm3, a melting point of 1 15.2 17℃ and a boiling point of 444.659℃. Monoclinic sulfur (S8), density 2.069g/cm3, melting point 1 15.2 17℃, boiling point 444.59℃; Pure elemental sulfur, density 2.069g/cm3, melting point 1 15.2 17℃, boiling point 444.59℃. Poor thermal and electrical conductivity. Crispy, insoluble in water. Amorphous sulfur is mainly elastic sulfur, which is obtained by rapidly pouring molten sulfur into ice water. Unstable, can be converted into crystalline sulfur. Crystalline sulfur can be dissolved in organic solvents such as carbon disulfide, while elastic sulfur can only be partially dissolved. The valence is -2, +2, +4 and +6. The first ionization energy is 10.360 eV. Its chemical properties are active, and it can combine with oxygen, metal, hydrogen, halogen (except iodine) and most known elements. It exists in positive and negative oxidation states and can form ionic compounds, valence compounds and coordination valence compounds.
Element source
Pyrite is the most important sulfide, followed by sulfide minerals of nonferrous metals (copper, lead, zinc, etc.). ). Among natural sulfates, gypsum CaSO4 2H2O and mirabilite Na2SO410h2o are the most abundant. It can be made of natural minerals or compounds.
Element usage
Most of them are used to make sulfuric acid. Rubber products industry, matches, fireworks, sulfate, sulfite, sulfide and other products also need a lot of sulfur. Part of it is used to make drugs, pesticides and bleaches. Elemental auxiliary data: Sulfur exists in nature as a single substance, and every volcanic eruption will bring a lot of underground sulfur to the ground. Sulfur also forms sulfides and sulfates with various metals, which are widespread in nature. Elemental sulfur is bright orange-yellow, which forms a strong pungent smell when burning. It can be asserted that sulfur was discovered and used in ancient times by the smell produced by the combustion of metal sulfides. In the west, the ancients believed that the thick smoke and strong smell formed when sulfur burned could drive away the devil. In the works of Pliny, an ancient Roman naturalist, it was written that sulfur was used to clean houses, because many people believed that the burning smell of sulfur could destroy all demons and all evil forces. About 4000 years ago, Egyptians used sulfur dioxide formed by sulfur combustion to bleach cloth. In the works of Homer, a famous Roman poet, it is also said that sulfur combustion has disinfection and bleaching effects. Alchemists in China and the West attach great importance to sulfur. They regard sulfur as the embodiment of flammability and think that it is one of the elements that make up all objects. China alchemists used a mixture of sulfur and saltpeter to make black powder. Whether in the west or in China, paleontologists have used sulfur in medicine. In Compendium of Materia Medica compiled by Li Shizhen, a famous doctor in China, the application of sulfur in medicine will be discussed: curing chronic cold of waist and kidney, removing stubborn cold and heat, and producing scabies with raw materials. The wide application of sulfur promotes the extraction and refining of sulfur. With the development of industry, sulfur plays a key role in the preparation of sulfuric acid, which is the mother of industry and is needed everywhere. 1894 American industrial chemist Frasch, who was born in Germany, invented the method of extracting sulfur directly from deep underground with superheated water. 1877, French chemist lavoisier published the first Su Zhang Garden Table in modern times, which included sulfur and confirmed the inseparability of sulfur. /kloc-In the second half of the 8th century, German chemist Michelich and French chemist Pomet discovered that sulfur has different crystal forms and put forward sulfur allotropes. At present, the most important crystalline sulfur is rhombic sulfur and monoclinic sulfur. They are all composed of S8 cyclic molecules.