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Niobium(V) Fluoride
Niobium(V) fluoride, also known as niobium pentafluoride, is the inorganic compound with the formula NbF5. The solid consists of tetramers bF5sub>4. It is a colorless solid that is rarely used. Preparation and reactions Niobium pentafluoride is obtained by treatment of any niobium compound with fluorine: :2 Nb + 5 F2 → 2 NbF5 :2 NbCl5 + 5 F2 → 2 NbF5 + 5 Cl2 It reacts with hydrogen fluoride to give H2NbF7, a superacid. Related compounds In hydrofluoric acid Hydrofluoric acid is a Solution (chemistry), solution of hydrogen fluoride (HF) in water. Solutions of HF are colourless, acidic and highly Corrosive substance, corrosive. It is used to make most fluorine-containing compounds; examples include th ..., NbF5 converts to bF7sup>2- and bF5Osup>2-. The relative solubility of these potassium salts and related tantalum fluorides is the basis of the Marignac process for separation of Nb and Ta. NbCl5 forms a dimeric structure (edge-shared bioctahedron) in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hygroscopic
Hygroscopy is the phenomenon of attracting and holding water molecules via either absorption or adsorption from the surrounding environment, which is usually at normal or room temperature. If water molecules become suspended among the substance's molecules, adsorbing substances can become physically changed, e.g., changing in volume, boiling point, viscosity or some other physical characteristic or property of the substance. For example, a finely dispersed hygroscopic powder, such as a salt, may become clumpy over time due to collection of moisture from the surrounding environment. ''Deliquescent'' materials are sufficiently hygroscopic that they absorb so much water that they become liquid and form an aqueous solution. Etymology and pronunciation The word ''hygroscopy'' () uses combining forms of '' hygro-'' and '' -scopy''. Unlike any other ''-scopy'' word, it no longer refers to a viewing or imaging mode. It did begin that way, with the word ''hygroscope'' referring in th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Niobium(IV) Fluoride
Niobium(IV) fluoride is a chemical compound with the formula . It is a nonvolatile black solid. Properties absorbs vapor strongly and turns into in moist air. It reacts with water to form a brown solution and a brown precipitate whose components are unknown. It is stable between 275 °C and 325 °C when heated in a vacuum. However, it disproportionates at 350 °C rapidly to form niobium(V) fluoride and niobium(III) fluoride: : (at 350 °C) Structure Niobium(IV) fluoride adopts a crystal structure analogous to that of tin(IV) fluoride Tin(IV) fluoride is a chemical compound of tin and fluorine with the chemical formula SnF4 and is a white solid with a melting point above 700 °C. SnF4 can be prepared by the reaction of tin metal with fluorine gas: :Sn + 2F2 → SnF4 Howev ..., in which each niobium atom is surrounded by six fluorine atoms forming an octahedron. Of the six fluorine atoms surrounding a single niobium atom, four are bridging to adjacent octahedra, lea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Niobium(V) Compounds
Niobium is a chemical element with chemical symbol Nb (formerly columbium, Cb) and atomic number 41. It is a light grey, crystalline, and ductile transition metal. Pure niobium has a Mohs hardness rating similar to pure titanium, and it has similar ductility to iron. Niobium oxidizes in Earth's atmosphere very slowly, hence its application in jewelry as a hypoallergenic alternative to nickel. Niobium is often found in the minerals pyrochlore and columbite, hence the former name "columbium". Its name comes from Greek mythology: Niobe, daughter of Tantalus, the namesake of tantalum. The name reflects the great similarity between the two elements in their physical and chemical properties, which makes them difficult to distinguish. English chemist Charles Hatchett reported a new element similar to tantalum in 1801 and named it columbium. In 1809, English chemist William Hyde Wollaston wrongly concluded that tantalum and columbium were identical. German chemist Heinrich Rose deter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
