Hydrogen fluoride
Other names	Hydrogen fluoride Fluoric acid Hydrofluoride Hydrofluoric acid Fluorine monohydride
Molecular formula	HF
Molecular mass	20. A chemical formula is a way of expressing information about the Atoms that constitute a particular Chemical compound, and how the relationship between those atoms changes The molecular mass (abbreviated m of a substance, more commonly referred to as molecular weight and abbreviated as MW, is the Mass of one 01 g/mol
Physical state	Liquid/Gas
CAS number	7664-39-3
Density	0. A state of matter (or physical state, or form of matter) has physical properties which are qualitatively different from other states of matter CAS registry numbers are unique numerical identifiers for Chemical compounds Polymers biological sequences mixtures and Alloys They are also referred to The density of a material is defined as its Mass per unit Volume: \rho = \frac{m}{V} Different materials usually have different 922 kg m-3
Solubility (water)	miscible
Melting point	-84 °C (190 K, -118 °F)
Boiling point	19. Solubility is the characteristic Physical property referring to the ability of a given substance the Solute, to dissolve in a Solvent. Water ( H2[[oxygen O]] H OH) is the most abundant Molecule on Earth 's surface composing of about 70% of the Earth's surface as The melting point of a solid is the temperature range at which it changes state from solid to Liquid. The boiling point of a liquid is the temperature at which the Vapor pressure of the liquid equals the environmental pressure surrounding the liquid 54 °C (293 K, 67. 2 °F)
NFPA 704	0 4 2
Disclaimer and references

Hydrogen fluoride is a chemical compound with the formula HF. Symbolism The four divisions are typically color-coded with blue indicating level of Health Hazard, red indicating A chemical compound is a substance consisting of two or more different elements chemically bonded together in a fixed proportion by Mass. A chemical formula is a way of expressing information about the Atoms that constitute a particular Chemical compound, and how the relationship between those atoms changes Together with hydrofluoric acid, it is the principal industrial source of fluorine and hence the precursor to many important compounds including pharmaceuticals and polymers (e. Hydrofluoric acid is a Solution of Hydrogen fluoride in Water. Fluorine, fluorum meaning "to flow" is the Chemical element with the symbol F and Atomic number 9 g. Teflon). Teflon is a Registered trademark and Brand name of the DuPont company for products made from three types of fluorine-containing polymers ( Fluoropolymers HF is widely used in the petrochemical industry and a component of many superacids. A superacid is an Acid with an Acidity greater than that of 100% Sulfuric acid, which has a Hammett acidity function ( H 0 HF boils just below room temperature whereas the other hydrogen halides condense at much lower temperatures. A halide is a Binary compound, of which one part is a Halogen Atom and the other part is an element or radical that is less Aqueous solutions of HF, called hydrofluoric acid, are strongly corrosive. Hydrofluoric acid is a Solution of Hydrogen fluoride in Water.

Contents 1 Structure 2 Acidity 3 Uses 4 Health effects 5 References

Structure

HF forms orthorhombic crystals, consisting of zig-zag chains of HF molecules. The HF molecules, with a short H-F bond of 0. 95 Å, are linked to neighboring molecules by intermolecular H--F distances of 1. 55 Å. ^[1]

Liquid HF also consists of chains of HF molecules, but the chains are shorter, consisting on average of only five or six molecules. ^[2] The higher boiling point of HF relative to analogous species, such as HCl, is attributed to hydrogen bonding between HF molecules, as indicated by the existence of chains even in the liquid state. A hydrogen bond results from a Dipole-dipole force between an Electronegative atom and a Hydrogen atom bonded to Nitrogen, Oxygen

Acidity

Dilute aqueous HF solutions are weakly acidic in contrast to corresponding solutions of the other hydrogen halides. A qualitative explanation for this behavior is related to the tendency of HF to hydrogen-bond and form ion-pair clusters such as F^-·H₃O⁺. ^[3][4]

In concentrated hydrogen fluoride solution, F⁻ ions forms a [HF₂]⁻(aq) complex with HF molecules. The bifluoride, or hydrogen(difluoride, ion is the species HF2− HF molecules remaining ionize to compensate the loss of F⁻ ions. More H⁺ ions are thus formed, making concentrated HF an effectively strong acid.

Anhydrous hydrogen fluoride is an extremely strong acid (H₀ ~ -11), comparable in strength to anhydrous sulfuric acid (H₀ ~ -12). The Hammett acidity function is a measure of acidity that is used for very concentrated solutions of strong acids including Superacids. Sulfuric (or sulphuric acid, H 2 S[[oxygen O]]4 is a strong Mineral acid.

Uses

HF is used for fluorinating polymers giving fluorocarbons, petroleum refining, glassmaking, aluminium manufacturing, titanium pickling, quartz purification, and metal finishing. A polymer is a large Molecule ( Macromolecule) composed of repeating Structural units typically connected by Covalent Chemical bonds Fluorocarbons are chemical compounds that contain Carbon - Fluorine bonds The relatively low reactivity and high polarity of the carbon-fluorine bond imparts Petroleum ( L petroleum, from Greek πετρέλαιον, lit WikipediaNaming Titanium (taɪˈteɪniəm is a Chemical element with the symbol Ti and Atomic number 22 Pickling is a treatment of Metallic surfaces in order to remove impurities stains Rust or scale with a solution called Pickle liquor, containing Quartz (from German) is the most abundant Mineral in the Earth 's Continental crust (although Feldspar is more common in It is also used to synthesize UF₆, which is key to separating uranium isotopes. Uranium hexafluoride (UF6 referred to as "hex" in the nuclear industry is a compound used in the Uranium enrichment process that produces Uranium (jʊˈreɪniəm is a silvery-gray Metallic Chemical element in the Isotopes (Greek isos = "equal" tópos = "site place" are any of the different types of atoms ( Nuclides

Hydrogen fluoride can be found in consumer products for removing rust, cleaning brass, and glass etching, although use in consumer products is discouraged due to HF's corrosiveness and toxicity. Rust is a general term for a series of Iron oxides, usually red oxides formed by the reaction of Iron with Oxygen in the presence of water or air Brass is any Alloy of Copper and Zinc; the proportions of zinc and copper can be varied to create a range of brasses with varying properties In Industry, etching (sometimes called chemical Milling or wet etching) is the process of using Acids bases or other Toxicity is the degree to which a substance is able to damage an exposed organism Hydrogen fluoride is typically marketed in three common forms: anhydrous HF, aqueous 70% HF, aqueous 49% HF. HF is manufactured by the reaction of calcium fluoride (fluorspar) and sulfuric acid:

CaF₂ + H₂SO₄ → CaSO₄ + 2 HF

The vapors from this reaction are a mixture of hydrogen fluoride, sulfuric acid, and a few minor byproducts. Calcium fluoride (CaF2 is an insoluble Ionic compound of Calcium and Fluorine. Sulfuric (or sulphuric acid, H 2 S[[oxygen O]]4 is a strong Mineral acid.

Health effects

Main article: Hydrofluoric acid

Upon contact with moisture, including tissue, hydrogen fluoride immediately converts to hydrofluoric acid, which is highly corrosive and toxic, and requires immediate medical attention. Hydrofluoric acid is a Solution of Hydrogen fluoride in Water. Hydrofluoric acid is a Solution of Hydrogen fluoride in Water.

References

1. ^ Johnson, M. W. ; Sándor, E. ; Arzi, E. (1975). "The Crystal Structure of Deuterium Fluoride". Acta Crystallographica B31: pages 1998–2003. Acta Crystallographica refers to a family of scientific Journals with peer-reviewed articles about Crystallography, published by the International Union of Crystallography doi:10.1107/S0567740875006711. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.  
2. ^ Mclain, Sylvia E. (2004). "On the Structure of Liquid Hydrogen Fluoride". Angewandte Chemie, International Edition 43: 1952–55. Angewandte Chemie is a weekly Peer-reviewed Chemistry journal that covers all disciplines of chemistry doi:10.1002/anie.200353289. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.  
3. ^ Giguere, Paul A. (1980). "The nature of hydrofluoric acid. A spectroscopic study of the proton-transfer complex H₃O⁺. . . F⁻". J. Am. Chem. Soc. 102: 5473. The Journal of the American Chemical Society (usually abbreviated as J doi:10.1021/ja00537a008. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.  
4. ^ Radu Iftimie, Vibin Thomas, Sylvain Plessis, Patrick Marchand, and Patrick Ayotte (2008). "Spectral Signatures and Molecular Origin of Acid Dissociation Intermediates". J. Am. Chem. Soc. 130: 5901. The Journal of the American Chemical Society (usually abbreviated as J doi:10.1021/ja077846o. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.  

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