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Fluorine Azide
Fluorine azide or triazadienyl fluoride is a yellow green gas composed of nitrogen and fluorine with formula . It is counted as an interhalogen compound, as the azide functional group is termed a pseudohalogen. It resembles , , and in this respect. The bond between the fluorine atom and the nitrogen is very weak, leading to this substance being very unstable and prone to explosion. Calculations show the F–N–N angle to be around 102° with a straight line of 3 nitrogen atoms. The gas boils at –30° and melts at –139 °C. It was first made by John F. Haller in 1942. Reactions Fluorine azide can be made by reacting hydrazoic acid and fluorine gas. Another way to form it is by reacting sodium azide with fluorine. Fluorine azide decomposes without explosion at normal temperatures to make dinitrogen difluoride: :. At higher temperatures such as 1000 °C fluorine azide breaks up into nitrogen monofluoride radical: : The FN itself dimerizes on cooling. : Sol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dinitrogen Difluoride
Dinitrogen difluoride is a chemical compound with the formula N2F2. It is a gas at room temperature, and was first identified in 1952 as the thermal decomposition product of the azide N3F. It has the structure F−N=N−F and exists in both a ''cis''- and ''trans''-form. Isomers The ''cis'' configuration lies in a C2v symmetry and the ''trans''-form has a symmetry of C2h. These isomers are thermally interconvertible but can be separated by low temperature fractionation. The ''trans''-form is less thermodynamically stable but can be stored in glass vessels. The ''cis''-form attacks glass over a time scale of about 2 weeks to form silicon tetrafluoride and nitrous oxide: :2 N2F2 + SiO2 → SiF4 + 2 N2O Preparation Most preparations of dinitrogen difluoride give mixtures of the two isomers, but they can be prepared independently. An aqueous method involves ''N'',''N''-difluorourea with concentrated potassium hydroxide. This gives a 40% yield with three times more o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrazoic Acid
Hydrazoic acid, also known as hydrogen azide or azoimide, This also contains a detailed description of the contemporaneous production process. is a compound with the chemical formula . It is a colorless, volatile, and explosive liquid at room temperature and pressure. It is a compound of nitrogen and hydrogen, and is therefore a pnictogen hydride. It was first isolated in 1890 by Theodor Curtius. The acid has few applications, but its conjugate acid, conjugate base, the azide ion, is useful in specialized processes. Hydrazoic acid, like its fellow mineral acids, is soluble in water. Undiluted hydrazoic acid is dangerously explosive with a standard enthalpy of formation ΔfHo (l, 298K) = +264 kJ/mol. When dilute, the gas and aqueous solutions (<10%) can be safely prepared but should be used immediately; because of its low boiling point, hydrazoic acid is enriched upon evaporation and condensation such that dilute solutions incapable of explosion can form droplets in the headspace o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arsenic Pentafluoride
Arsenic pentafluoride is a chemical compound of arsenic and fluorine. It is a toxic, colorless gas. The oxidation state of arsenic is +5. Synthesis Arsenic pentafluoride can be prepared by direct combination of arsenic and fluorine: :2As + 5F2 → 2AsF5 It can also be prepared by the reaction of arsenic trifluoride and fluorine: :AsF3 + F2 → AsF5 or the addition of fluorine to arsenic pentoxide or arsenic trioxide. :2As2O5 + 10F2 → 4AsF5 + 5O2 :2As2O3 + 10F2 → 4AsF5 + 3O2 Properties Arsenic pentafluoride is a colourless gas and has a trigonal bipyramidal structure. In the solid state the axial As−F bond lengths are 171.9 pm and the equatorial 166.8 pm. Its point group is D3h. Reactions Arsenic pentafluoride forms halide complexes and is a powerful fluoride acceptor. An example is the reaction with sulfur tetrafluoride, forming an ionic hexafluoroarsenate complex.An investigation of the structures of the adducts of SF4 with BF3, PF5, AsF5, and SbF5 in the solid sta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Explosive Gases
An explosive (or explosive material) is a reactive substance that contains a great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light, heat, sound, and pressure. An explosive charge is a measured quantity of explosive material, which may either be composed solely of one ingredient or be a mixture containing at least two substances. The potential energy stored in an explosive material may, for example, be * chemical energy, such as nitroglycerin or grain dust * pressurized gas, such as a gas cylinder, aerosol can, or BLEVE * nuclear energy, such as in the fissile isotopes uranium-235 and plutonium-239 Explosive materials may be categorized by the speed at which they expand. Materials that detonate (the front of the chemical reaction moves faster through the material than the speed of sound) are said to be "high explosives" and materials that deflagrate are said to be "low explosives". Explosives may als ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gases With Color
Gas is one of the four fundamental states of matter (the others being solid, liquid, and plasma). A pure gas may be made up of individual atoms (e.g. a noble gas like neon), elemental molecules made from one type of atom (e.g. oxygen), or compound molecules made from a variety of atoms (e.g. carbon dioxide). A gas mixture, such as air, contains a variety of pure gases. What distinguishes a gas from liquids and solids is the vast separation of the individual gas particles. This separation usually makes a colourless gas invisible to the human observer. The gaseous state of matter occurs between the liquid and plasma states, the latter of which provides the upper temperature boundary for gases. Bounding the lower end of the temperature scale lie degenerative quantum gases which are gaining increasing attention. High-density atomic gases super-cooled to very low temperatures are classified by their statistical behavior as either Bose gases or Fermi gases. For a comprehensive list ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Azido Compounds
In chemistry, azide is a linear, polyatomic anion with the formula and structure . It is the conjugate base of hydrazoic acid . Organic azides are organic compounds with the formula , containing the azide functional group. The dominant application of azides is as a propellant in air bags. Preparation Sodium azide is made industrially by the reaction of nitrous oxide, with sodium amide in liquid ammonia as solvent: : Many inorganic azides can be prepared directly or indirectly from sodium azide. For example, lead azide, used in detonators, may be prepared from the metathesis reaction between lead nitrate and sodium azide. An alternative route is direct reaction of the metal with silver azide dissolved in liquid ammonia. Some azides are produced by treating the carbonate salts with hydrazoic acid. Bonding Azide is isoelectronic with carbon dioxide , cyanate , nitrous oxide , nitronium ion and cyanogen fluoride NCF. Per valence bond theory, azide can be desc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluorine Compounds
Fluorine forms a great variety of chemical compounds, within which it always adopts an oxidation state of −1. With other atoms, fluorine forms either polar covalent bonds or ionic bonds. Most frequently, covalent bonds involving fluorine atoms are single bonds, although at least two examples of a higher order bond exist. Fluoride may act as a bridging ligand between two metals in some complex molecules. Molecules containing fluorine may also exhibit hydrogen bonding (a weaker bridging link to certain nonmetals). Fluorine's chemistry includes inorganic compounds formed with hydrogen, metals, nonmetals, and even noble gases; as well as a diverse set of organic compounds.In this article, metalloids are not treated separately from metals and nonmetals, but among elements they are closer to. For example, germanium is treated as a metal, and silicon as a nonmetal. Antimony is included for comparison among nonmetals, even though it is closer to metals chemically than to nonmetals. The no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photoelectric Spectrum
Photoemission spectroscopy (PES), also known as photoelectron spectroscopy, refers to energy measurement of electrons emitted from solids, gases or liquids by the photoelectric effect, in order to determine the binding energies of electrons in the substance. The term refers to various techniques, depending on whether the ionization energy is provided by X-ray, XUV or UV photons. Regardless of the incident photon beam, however, all photoelectron spectroscopy revolves around the general theme of surface analysis by measuring the ejected electrons. Types X-ray photoelectron spectroscopy (XPS) was developed by Kai Siegbahn starting in 1957 and is used to study the energy levels of atomic core electrons, primarily in solids. Siegbahn referred to the technique as "electron spectroscopy for chemical analysis" (ESCA), since the core levels have small chemical shifts depending on the chemical environment of the atom that is ionized, allowing chemical structure to be determined. Siegbahn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium Fluoride
Sodium fluoride (NaF) is an inorganic compound with the formula . It is used in trace amounts in the fluoridation of drinking water, in toothpaste, in metallurgy, and as a flux. It is a colorless or white solid that is readily soluble in water. It is a common source of fluoride in the production of pharmaceuticals and is used to prevent dental cavities. In 2020, it was the 265th most commonly prescribed medication in the United States, with more than 1million prescriptions. Uses Dental caries Fluoride salts are often added to municipal drinking water (as well as to certain food products in some countries) for the purpose of maintaining dental health. The fluoride enhances the strength of teeth by the formation of fluorapatite, a naturally occurring component of tooth enamel. Although sodium fluoride is used to fluoridate water and is the standard by which other water-fluoridation compounds are gauged, hexafluorosilicic acid (H2SiF6) and its salt sodium hexafluorosilica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lithium Fluoride
Lithium fluoride is an inorganic compound with the chemical formula LiF. It is a colorless solid, that transitions to white with decreasing crystal size. Although odorless, lithium fluoride has a bitter-saline taste. Its structure is analogous to that of sodium chloride, but it is much less soluble in water. It is mainly used as a component of molten salts. Formation of LiF from the elements releases one of the highest energy per mass of reactants, second only to that of BeO. Manufacturing LiF is prepared from lithium hydroxide or lithium carbonate with hydrogen fluoride. Applications Precursor to LiPF6 for batteries Lithium fluoride is reacted with hydrogen fluoride (HF) and phosphorus pentachloride to make lithium hexafluorophosphate, an ingredient in lithium ion battery electrolyte. In molten salts Fluorine is produced by the electrolysis of molten potassium bifluoride. This electrolysis proceeds more efficiently when the electrolyte contains a few percent of LiF, possibly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potassium Fluoride
Potassium fluoride is the chemical compound with the formula KF. After hydrogen fluoride, KF is the primary source of the fluoride ion for applications in manufacturing and in chemistry. It is an alkali halide and occurs naturally as the rare mineral carobbiite. Solutions of KF will etch glass due to the formation of soluble fluorosilicates, although HF is more effective. Preparation Potassium fluoride is prepared by dissolving potassium carbonate in hydrofluoric acid. Evaporation of the solution forms crystals of potassium bifluoride. The bifluoride on heating yields potassium fluoride: : K2CO3 + 4HF -> 2KHF2 + CO2 ^ + H2O : KHF2 -> KF + HF ^ Platinum or heat resistant plastic containers are often used for these operations. Potassium chloride converts to KF upon treatment with hydrogen fluoride. In this way, potassium fluoride is recyclable. Crystalline properties KF crystallizes in the cubic NaCl crystal structure. The lattice parameter at room temperature is 0.266 nm. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adsorb
Adsorption is the adhesion of atoms, ions or molecules from a gas, liquid or dissolved solid to a surface. This process creates a film of the ''adsorbate'' on the surface of the ''adsorbent''. This process differs from absorption, in which a fluid (the ''absorbate'') is dissolved by or permeates a liquid or solid (the ''absorbent''). Adsorption is a '' surface phenomenon'', while absorption involves the whole volume of the material, although adsorption does often precede absorption. The term ''sorption'' encompasses both processes, while ''desorption'' is the reverse of it. Like surface tension, adsorption is a consequence of surface energy. In a bulk material, all the bonding requirements (be they ionic, covalent or metallic) of the constituent atoms of the material are fulfilled by other atoms in the material. However, atoms on the surface of the adsorbent are not wholly surrounded by other adsorbent atoms and therefore can attract adsorbates. The exact nature of the bond ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
