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Hittorf's Phosphorus
Elemental phosphorus can exist in several allotropes, the most common of which are white and red solids. Solid violet and black allotropes are also known. Gaseous phosphorus exists as diphosphorus and atomic phosphorus. White phosphorus White phosphorus, yellow phosphorus or simply tetraphosphorus () exists as molecules of four phosphorus atoms in a tetrahedral structure, joined by six phosphorus—phosphorus single bonds. The free P4 molecule in the gas phase has a P-P bond length of ''r''g = 2.1994(3) Å as was determined by gas electron diffraction. Despite the tetrahedral arrangement the P4 molecules have no significant ring strain and a vapor of P4 molecules is stable. This is due to the nature of bonding in the P4 tetrahedron which can be described by spherical aromaticity or cluster bonding, that is the electrons are highly delocalized. This has been illustrated by calculations of the magnetically induced currents, which sum up to 29 nA/T, much more than in the arche ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benzene
Benzene is an Organic compound, organic chemical compound with the Chemical formula#Molecular formula, molecular formula C6H6. The benzene molecule is composed of six carbon atoms joined in a planar hexagonal Ring (chemistry), ring with one hydrogen atom attached to each. Because it contains only carbon and hydrogen atoms, benzene is classed as a hydrocarbon. Benzene is a natural constituent of petroleum and is one of the elementary petrochemicals. Due to the cyclic continuous pi bonds between the carbon atoms, benzene is classed as an aromatic hydrocarbon. Benzene is a colorless and highly Combustibility and flammability, flammable liquid with a sweet smell, and is partially responsible for the aroma of gasoline. It is used primarily as a Precursor (chemistry), precursor to the manufacture of chemicals with more complex structures, such as ethylbenzene and cumene, of which billions of kilograms are produced annually. Although benzene is a major Chemical industry, industrial che ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Industrial Furnace
An industrial furnace is a device used to provide heat for an industrial process, typically operating at temperatures above 400 degrees Celsius. These furnaces generate heat by combusting fuel with air or oxygen, or through Electricity, electrical energy, and are used across various industries for applications such as chemical reactions, cremation, Oil refinery, oil refining, and Glass melting furnace, glasswork. The residual heat is expelled as flue gas. While the term industrial furnace encompasses a wide range of high-temperature equipment, one specific type is the direct fired heater, also known as a direct fired furnace or process furnace. Direct fired heaters are primarily used in refinery and petrochemical applications to efficiently transfer heat to process fluids by means of combustion. Unlike other industrial furnaces used in metallurgical furnace, metallurgy or batch ovens, direct fired heaters are optimized for precise temperature control and high thermal efficiency ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphate Rock
Phosphorite, phosphate rock or rock phosphate is a non- detrital sedimentary rock that contains high amounts of phosphate minerals. The phosphate content of phosphorite (or grade of phosphate rock) varies greatly, from 4% to 20% phosphorus pentoxide (P2O5). Marketed phosphate rock is enriched ("beneficiated") to at least 28%, often more than 30% P2O5. This occurs through washing, screening, de-liming, magnetic separation or flotation. By comparison, the average phosphorus content of sedimentary rocks is less than 0.2%.Blatt, Harvey and Robert J. Tracy, ''Petrology'', Freeman, 1996, 2nd ed. pp. 345–349 The phosphate is present as fluorapatite Ca5(PO4)3F typically in cryptocrystalline masses (grain sizes < 1 μm) referred to as collophane-sedimentary apatite deposits of uncertain origin. It is also present as |
Disulfur Dichloride
Disulfur dichloride (or disulphur dichloride by the British English spelling) is the inorganic compound of sulfur and chlorine with the Chemical formula, formula . It is an amber oily liquid. Sometimes, this compound is incorrectly named ''sulfur monochloride'' (or ''sulphur monochloride'' by the British English spelling), the name implied by its empirical formula SCl. has the structure implied by the formula , wherein the dihedral angle between the and planes is 85.2°. This structure is referred to as Conformational isomerism, gauche, and is akin to that for Hydrogen peroxide, . A rare isomer of is (thiothionyl chloride); this isomer forms transiently when is exposed to UV-radiation (see thiosulfoxides). Synthesis, basic properties, reactions Disulfur dichloride is a yellow liquid that fumes in moist air due to reaction with water: : It is produced by partial chlorination of elemental sulfur. The reaction proceeds at usable rates at room temperature. In the laboratory, c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbon Disulfide
Carbon disulfide (also spelled as carbon disulphide) is an inorganic compound with the chemical formula and structure . It is also considered as the anhydride of thiocarbonic acid. It is a colorless, flammable, neurotoxic liquid that is used as a building block in organic synthesis. Pure carbon disulfide has a pleasant, ether- or chloroform-like odor, but commercial samples are usually yellowish and are typically contaminated with foul-smelling impurities.. History In 1796, the German chemist Wilhelm August Lampadius (1772–1842) first prepared carbon disulfide by heating pyrite with moist charcoal. He called it "liquid sulfur" (''flüssig Schwefel''). The composition of carbon disulfide was finally determined in 1813 by the team of the Swedish chemist Jöns Jacob Berzelius (1779–1848) and the Swiss-British chemist Alexander Marcet (1770–1822). Their analysis was consistent with an empirical formula of CS2. Occurrence, manufacture, properties Small amounts of carbon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oils
An oil is any nonpolar chemical substance that is composed primarily of hydrocarbons and is hydrophobic (does not mix with water) and lipophilic (mixes with other oils). Oils are usually flammable and surface active. Most oils are unsaturated lipids that are liquid at room temperature. The general definition of oil includes classes of chemical compounds that may be otherwise unrelated in structure, properties, and uses. Oils may be animal, vegetable, or petrochemical in origin, and may be volatile or non-volatile. They are used for food (e.g., olive oil), fuel (e.g., heating oil), medical purposes (e.g., mineral oil), lubrication (e.g. motor oil), and the manufacture of many types of paints, plastics, and other materials. Specially prepared oils are used in some religious ceremonies and rituals as purifying agents. Etymology First attested in English 1176, the word ''oil'' comes from Old French ''oile'', from -4; we might wonder whether there's a point at which it's ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deutsche Welle
(; "German Wave"), commonly shortened to DW (), is a German state-funded television network, state-owned international broadcaster funded by the Federal Government of Germany. The service is available in 32 languages. DW's satellite television service consists of channels in English, Spanish, and Arabic. The work of DW is regulated by the Act, stating that content is intended to be independent of government influence. DW is a member of the European Broadcasting Union (EBU). DW offers regularly updated articles on its news website and runs its own centre for international media development, DW Akademie. The broadcaster's stated goals are to produce reliable news coverage, provide access to the German language, and promote understanding between peoples. It is also a provider of live streaming world news, which, like all DW programs, can be viewed and listened via its website, YouTube, satellite, rebroadcasting and various apps and digital media players. DW has been ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beachcombing
Beachcombing is an activity that consists of an individual "combing" (or searching) the beach and the intertidal zone, looking for things of value, interest or utility. A beachcomber is a person who participates in the activity of beachcombing. Despite these general definitions, beachcombing and beachcomber are words with multiple, but related, meanings that have evolved over time. Historical usage The first appearance of the word "beachcombers" in print was in Richard Henry Dana Jr.'s '' Two Years Before the Mast'' (1840) and later referenced in Herman Melville's '' Omoo'' (1847). It described a population of Europeans who lived in South Pacific islands, "combing" the beach and nearby water for flotsam, jetsam, or anything else they could use or trade. When a beachcomber became totally dependent upon coastal fishing for his sustenance, or abandoned his original culture and set of values ("went native"), then the term "beachcomber" was synonymous with a criminal, a drifter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphorus Trioxide
Phosphorus trioxide is the chemical compound with the molecular formula P4O6. Although the molecular formula suggests the name tetraphosphorus hexoxide, the name phosphorus trioxide preceded the knowledge of the compound's molecular structure, and its usage continues today. This colorless solid is structurally related to adamantane. It is formally the anhydride of phosphorous acid, H3PO3, but cannot be obtained by the dehydration of the acid. A white solid that melts at room temperature, it is waxy, crystalline and highly toxic, with garlic odor. Preparation It is obtained by the combustion of phosphorus in a limited supply of air at low temperatures. :P4 + 3 O2 → P4O6 By-products include red phosphorus suboxide. Chemical properties Phosphorus trioxide reacts with water to form phosphorous acid, reflecting the fact that it is the anhydride of that acid. : P4O6 + 6 H2O → 4 H3PO3 It reacts with hydrogen chloride to form H3PO3 and phosphorus trichloride. : P4O6 + ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
White Phosphorus Munitions
White phosphorus munitions are weapons that use one of the common allotropes of the chemical element phosphorus. White phosphorus is used in smoke, illumination, and incendiary munitions, and is commonly the burning element of tracer ammunition. Other common names for white phosphorus munitions include ''WP'' and the slang terms ''Willie Pete'' and ''Willie Peter'', which are derived from ''William Peter'', the World War II phonetic alphabet rendering of the letters ''WP''. White phosphorus is pyrophoric (it is ignited by contact with air); burns fiercely; and can ignite cloth, fuel, ammunition, and other combustibles. White phosphorus is a highly efficient smoke-producing agent, reacting with air to produce an immediate blanket of phosphorus pentoxide vapour. Smoke-producing white phosphorus munitions are very common, particularly as smoke grenades for infantry, loaded in defensive grenade launchers on tanks and other armoured vehicles, and in the ammunition allotment for a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Melting-point Depression
:''This article deals with melting/freezing point depression due to very small particle size. For depression due to the mixture of another compound, see freezing-point depression.'' Melting-point depression is the phenomenon of reduction of the melting point of a material with a reduction of its size. This phenomenon is very prominent in nanoscale materials, which melt at temperatures hundreds of degrees lower than bulk materials. Introduction The melting temperature of a bulk material is not dependent on its size. However, as the dimensions of a material decrease towards the atomic scale, the melting temperature scales with the material dimensions. The decrease in melting temperature can be on the order of tens to hundreds of degrees for metals with nanometer dimensions. Melting-point depression is most evident in nanowires, nanotubes and nanoparticles, which all melt at lower temperatures than bulk amounts of the same material. Changes in melting point occur because nanosca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
