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Hydrogen fluoride is typically produced by the reaction between sulfuric acid and pure grades of the mineral fluorite: [14] CaF 2 + H 2 SO 4 → 2 HF + CaSO 4. About 20% of manufactured HF is a byproduct of fertilizer production, which generates hexafluorosilicic acid. This acid can be degraded to release HF thermally and by hydrolysis: H 2 SiF ...
Although hydrofluoric acid is regarded as a weak acid, it is very corrosive, even attacking glass when hydrated. [ 20 ] Dilute solutions are weakly acidic with an acid ionization constant K a = 6.6 × 10 −4 (or p K a = 3.18 ), [ 10 ] in contrast to corresponding solutions of the other hydrogen halides, which are strong acids ( p K a < 0 ).
Limescale build-up inside a pipe reduces both liquid flow and thermal conduction from the pipe, so will reduce thermal efficiency when used as a heat exchanger.. A descaling agent or chemical descaler is a liquid chemical substance used to remove limescale from metal surfaces in contact with hot water, such as in boilers, water heaters, and kettles.
The typical hydrofluoric acid (HF) alkylation unit requires far less acid than a sulfuric acid unit to achieve the same volume of alkylate. The HF process only creates a small amount of organofluorine side products which are continuously removed from the reactor and the consumed HF is replenished.
Hydrogen fluoride, a weak acid in aqueous solution that is normally not thought to have any appreciable Brønsted basicity at all, is in fact the strongest Brønsted base in the mixture, protonating to H 2 F + in the same way water protonates to H 3 O + in aqueous acid. It is the fluoronium ion that accounts for fluoroantimonic acid's extreme ...
Will rapidly or completely vaporize at normal atmospheric pressure and temperature, or is readily dispersed in air and will burn readily (e.g., gasoline, acetylene, propane, hydrogen gas, diborane, tert-Butyllithium). Includes pyrophoric substances. Flash point below room temperature at 22.8 °C (73 °F).
They are frequently used in air conditioning and as refrigerants; R-134a (1,1,1,2-tetrafluoroethane) is one of the most commonly used HFC refrigerants. In order to aid the recovery of the stratospheric ozone layer, HFCs were adopted to replace the more potent chlorofluorocarbons (CFCs), which were phased out from use by the Montreal Protocol ...
Potassium bifluoride is a related more commonly used etchant. Ammonium bifluoride has been considered as an intermediate in the production of hydrofluoric acid from hexafluorosilicic acid. Thus, hexafluorosilicic acid is hydrolyzed to give ammonium fluoride, which thermally decomposes to give the bifluoride: H 2 [SiF 6] + 6 NH 3 + 2 H 2 O → ...