Search results
Results from the WOW.Com Content Network
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 ...
The lethal dose for most adult humans is estimated at 5 to 10 g (which is equivalent to 32 to 64 mg elemental fluoride per kg body weight). [53] [54] [55] A case of a fatal poisoning of an adult with 4 grams of sodium fluoride is documented, [56] and a dose of 120 g sodium fluoride has been survived. [57]
An equivalent (symbol: officially equiv; [1] unofficially but often Eq [2]) is the amount of a substance that reacts with (or is equivalent to) an arbitrary amount (typically one mole) of another substance in a given chemical reaction. It is an archaic quantity that was used in chemistry and the biological sciences (see Equivalent weight § In ...
Substance Formula 0 °C 10 °C 20 °C 30 °C 40 °C 50 °C 60 °C 70 °C 80 °C 90 °C 100 °C Barium acetate: Ba(C 2 H 3 O 2) 2: 58.8: 62: 72: 75: 78.5: 77: 75
The U.S. Public Health Service currently recommends a fluoride level of 0.7 milligrams per liter of water to maximize oral health benefits while minimizing the risk of fluorosis, a condition ...
The following chart shows the solubility of various ionic compounds in water at 1 atm pressure and room temperature (approx. 25 °C, 298.15 K). "Soluble" means the ionic compound doesn't precipitate, while "slightly soluble" and "insoluble" mean that a solid will precipitate; "slightly soluble" compounds like calcium sulfate may require heat to precipitate.
Hydrofluoric acid is a solution of hydrogen fluoride (HF) in water.Solutions of HF are colorless, acidic and highly corrosive.A common concentration is 49% (48–52%) but there are also stronger solutions (e.g. 70%) and pure HF has a boiling point near room temperature.
Unlike other hydrohalic acids, such as hydrochloric acid, hydrogen fluoride is only a weak acid in water solution, with acid dissociation constant (pK a) equal to 3.19. [36] HF's weakness as an aqueous acid is paradoxical considering how polar the HF bond is, much more so than the bond in HCl, HBr, or HI. The explanation for the behavior is ...