What is the most powerful acid?
1362114#3
Anhydrous aluminium chloride is a most powerful Lewis acid, capable of forming Lewis acid-base adducts with even weak Lewis bases such as benzophenone and mesitylene. It forms tetrachloroaluminate AlCl in the presence of chloride ions.
Aluminium chloride
3465676#0
Fluoroantimonic acid is an inorganic compound with the chemical formula (also written , 2HF·SbF, or simply HF-SbF). It is an extremely strong acid, easily qualifying as a superacid. The Hammett acidity function, "H", has been measured for different ratios of HF:SbF. While the "H" of pure HF is −15, addition of just 1 mol % of SbF lowers it to around −20. However, further addition of SbF results in rapidly diminishing returns, with the "H" reaching −21 at 10 mol %. The use of an extremely weak base as indicator shows that the lowest attainable "H", even with > 50 mol % SbF, is somewhere between −21 and −23.
Fluoroantimonic acid
5052563#0
Xenic acid is a noble gas compound formed by the dissolution of xenon trioxide in water. Its chemical formula is HXeO. It is a very powerful oxidizing agent, and its decomposition is dangerous as it liberates a large amount of gaseous products: xenon, oxygen, and ozone. However, this feature is also what makes xenic acid practically useful in syntheses: there is no chance of introducing impurities to the oxidation products, as all the byproducts can be trivially evaporated.
Xenic acid
30862640#4
Acid attacks often occur as revenge against a woman who rejects a proposal of marriage or a sexual advance. Gender inequality and women's position in the society, in relation to men, plays a significant role in these types of attacks.
Attacks against individuals based on their religious beliefs or social or political activities also occur. These attacks may be targeted against a specific individual, due to their activities, or may be perpetrated against random persons merely because they are part of a social group or community. In Europe, Konstantina Kouneva, currently a member of the European Parliament, had acid thrown on her in 2008, in what was described as "the most severe assault on a trade unionist in Greece for 50 years." Female students have had acid thrown in their faces as a punishment for attending school. Acid attacks due to religious conflicts have been also reported. Both males and females have been victims of acid attacks for refusing to convert to another religion.
Acid throwing
1362114#13
AlCl is probably the most commonly used Lewis acid and also one of the most powerful. It finds application in the chemical industry as a catalyst for Friedel–Crafts reactions, both acylations and alkylations. Important products are detergents and ethylbenzene. It also finds use in polymerization and isomerization reactions of hydrocarbons.
Aluminium chloride
20839993#10
At lower temperatures in the presence of NaOH, (diacetoxyiodo)benzene can also be hydrolyzed to iodosylbenzene which is actually a polymer with the molecular formula (CHOI). Iodosylbenzene is used in organic oxidations. Dess-Martin periodinane (1983) is another powerful oxidant and an improvement of the IBX acid already in existence in 1983. The IBX acid is prepared from 2-iodobenzoic acid and potassium bromate and sulfuric acid and is insoluble in most solvents whereas the Dess-Martin reagent prepared from reaction of the IBX acid with acetic anhydride is very soluble. The oxidation mechanism ordinarily consists of a ligand exchange reaction followed by a reductive elimination.
Iodane
2182805#3
Dess-Martin periodinane (1983) is another powerful oxidant and an improvement of the IBX acid already in existence in 1983. The IBX acid is prepared from 2-iodobenzoic acid and potassium bromate and sulfuric acid and is insoluble in most solvents whereas the Dess-Martin reagent prepared from reaction of the IBX acid with acetic anhydride is very soluble. The oxidation mechanism ordinarily consists of a ligand exchange reaction followed by a reductive elimination.
The predominant use of periodinanes is as oxidizing reagents replacing toxic reagents based on heavy metals.
Periodinane
21655#17
Being a powerful oxidizing agent, nitric acid reacts violently with many non-metallic compounds, and the reactions may be explosive. Depending on the acid concentration, temperature and the reducing agent involved, the end products can be variable. Reaction takes place with all metals except the noble metals series and certain alloys. As a general rule, oxidizing reactions occur primarily with the concentrated acid, favoring the formation of nitrogen dioxide (NO). However, the powerful oxidizing properties of nitric acid are thermodynamic in nature, but sometimes its oxidation reactions are rather kinetically non-favored. The presence of small amounts of nitrous acid (HNO) greatly enhance the rate of reaction.
Nitric acid
39667666#5
In the gas phase, H(CHBF) has a computed acidity of 216 kcal/mol, compared to an experimentally determined acidity of 241 kcal/mol (in reasonable agreement with the computed value of 230 kcal/mol) for H(CHBCl). In contrast, HSbF (a simplified model for the proton donating species in fluoroantimonic acid) has a computed gas phase acidity of 255 kcal/mol, while the previous experimentally determined record holder was (CFSO)NH, a congener of bistriflimide, at 291 kcal/mol. Thus, H(CHBF) is likely the most acidic substance so far synthesized in bulk, in terms of its gas phase acidicity. In view of its unique reactivity, it is also a strong contender for being the most acidic substance in the condensed phase (see above). Some even more strongly acidic derivatives have been predicted, with gas phase acidities < 200 kcal/mol and approaching the measured acidity of helionium ion (gas phase acidity 178 kcal/mol), HeH, the most acidic species possible.
Carborane acid
19600890#1
Tartaric acid is, from a winemaking perspective, the most important in wine due to the prominent role it plays in maintaining the chemical stability of the wine and its color and finally in influencing the taste of the finished wine. In most plants, this organic acid is rare, but it is found in significant concentrations in grape vines. Along with malic acid, and to a lesser extent citric acid, tartaric is one of the fixed acids found in wine grapes. The concentration varies depending on grape variety and the soil content of the vineyard. Some varieties, such as Palomino, are naturally disposed to having high levels of tartaric acids, while Malbec and Pinot noir generally have lower levels. During flowering, high levels of tartaric acid are concentrated in the grape flowers and then young berries. As the vine progresses through ripening, tartaric does not get metabolized through respiration like malic acid, so the levels of tartaric acid in the grape vines remain relatively consistent throughout the ripening process.
Acids in wine
39667666#6
Carborane acids differ from classical superacids in being well-defined one component substances. In contrast, classical superacids are often mixtures of a Brønsted acid and Lewis acid (e.g. HF/SbF). Despite being the strongest acid, the boron-based carborane acids are described as being "gentle", cleanly protonating weakly basic substances without further side reactions. Whereas conventional superacids decompose fullerenes due to their strongly oxidizing Lewis acidic component, carborane acid has the ability to protonate fullerenes at room temperature to yield an isolable salt. Furthermore, the anion that forms as a result of proton transfer is nearly completely inert. This property is what makes the carborane acids the only substances that are comparable in acidity to the mixed superacids that can also be stored in a glass bottle, as various fluoride-donating species (which attack glass) are not present or generated.
Carborane acid