Search results
Results from the WOW.Com Content Network
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.
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 ...
Sodium bifluoride reacts with water or moist skin to produce hydrofluoric acid. It also gives off hydrofluoric acid and hydrogen gas when it is heated to a gaseous state. The chemical can decompose upon contact with strong acids, strong bases, metal, water, or glass. [3] Sodium bifluoride also engages in violent reactions with chromyl chloride ...
In water, ammonium bifluoride exists in chemical equilibrium with hydrofluoric acid and heating releases hydrogen fluoride gas. [9] Consequently, there is an equivalent toxicological risk as is present with hydrofluoric acid, and the same safety precautions apply. [10] [9] Ammonium bifluoride is used in some automotive wheel cleaning products.
It is a mixture of a buffering agent, such as ammonium fluoride NH 4 F, and hydrofluoric acid (HF). Its primary use is in etching thin films of silicon nitride (Si 3 N 4) or silicon dioxide (SiO 2), by the reaction: SiO 2 + 4HF + 2NH 4 F → (NH 4) 2 SiF 6 + 2H 2 O
Like water and ammonia, liquid hydrogen fluoride supports an acid–base chemistry. Using a solvent system definition of acidity and basicity, nitric acid functions as a base when it is added to liquid HF. [70] However, hydrogen fluoride is cosmically rare, unlike water, ammonia, and methane. [71]
In chemistry, an acid–base reaction is a chemical reaction that occurs between an acid and a base.It can be used to determine pH via titration.Several theoretical frameworks provide alternative conceptions of the reaction mechanisms and their application in solving related problems; these are called the acid–base theories, for example, Brønsted–Lowry acid–base theory.
In acid catalysis and base catalysis, a chemical reaction is catalyzed by an acid or a base. By Brønsted–Lowry acid–base theory, the acid is the proton (hydrogen ion, H +) donor and the base is the proton acceptor. Typical reactions catalyzed by proton transfer are esterifications and aldol reactions.