Фтороводород: свойства и применение

chembox
|verifiedrevid = 476992809
|Name = Hydrogen fluoride
|ImageFileL1 = Hydrogen fluoride 2D dimensions. svg
|ImageFile = Hydrogen fluoride. svg
|ImageFileR1 = Hydrogen fluoride 3D vdW. svg
|OtherNames = Fluorane
|Section1 =
|Section2 = Chembox Properties
|H=1 | F=1
|Formula = HF
|Appearance = colourless gas or colourless liquid (below 19.5 °C)
|Odor = unpleasant
|Density = 1.15 g/L, gas (25 °C)0.99 g/mL, liquid (19.5 °C)1.663 g/mL, solid (–125 °C)
|Solubility = completely miscible (liquid)
|MeltingPtC = 83.6
|BoilingPtC = 19.5
|RefractIndex = 1.00001
|pKa = 3.17 (in water),
15 (in DMSO)
|ConjugateAcid = Fluoronium
|ConjugateBase = Fluoride
|VaporPressure = 783 mmHg (20 °C)
|REL = TWA 3 ppm (2.5 mg/m3) C 6 ppm (5 mg/m3) [15 minute]
|LCLo = 313 ppm (rabbit, 7 hr) Liquid HF also consists of chains of HF molecules, but the chains are shorter, consisting on average of only five or six molecules.

Hydrogen fluoride does not boil until 20 °C in contrast to the heavier hydrogen halides, which boil between −85 °C (−120 °F) and −35 °C (−30 °F). This hydrogen bonding between HF molecules gives rise to high viscosity in the liquid phase and lower than expected pressure in the gas phase.

Like water, HF can act as a weak base, reacting with Lewis acids to give superacids. A Hammett acidity function (H0) of −21 is obtained with antimony pentafluoride (SbF5), forming fluoroantimonic acid.

HF serves as a catalyst in alkylation processes in refineries. It is used in the majority of the installed linear alkyl benzene production facilities in the world. The process involves dehydrogenation of n paraffins to olefins, and subsequent reaction with benzene using HF as catalyst. For example, in oil refineries "alkylate", a component of high octane petrol (gasoline), is generated in alkylation units, which combine C3 and C4 olefins and iso butane.

Hydrogen fluoride is an excellent solvent. Reflecting the ability of HF to participate in hydrogen bonding, even proteins and carbohydrates dissolve in HF and can be recovered from it. In contrast, most non fluoride inorganic chemicals react with HF rather than dissolving.

Hydrogen fluoride is highly corrosive and a powerful contact poison. Exposure requires immediate medical attention. It can cause blindness by rapid destruction of the corneas. Breathing in hydrogen fluoride at high levels or in combination with skin contact can cause death from an irregular heartbeat or from pulmonary edema (fluid buildup in the lungs).