Search results
Results from the WOW.Com Content Network
Acid strength is the tendency of an acid, symbolised by the chemical formula, to dissociate into a proton, +, and an anion, .The dissociation or ionization of a strong acid in solution is effectively complete, except in its most concentrated solutions.
Nitric acid, with a pK value of around −1.7, behaves as a strong acid in aqueous solutions with a pH greater than 1. [23] At lower pH values it behaves as a weak acid. pK a values for strong acids have been estimated by theoretical means. [24] For example, the pK a value of aqueous HCl has been estimated as −9.3.
Fluoroantimonic acid is a mixture of hydrogen fluoride and antimony pentafluoride, containing various cations and anions (the simplest being H 2 F + and Sb F − 6).This mixture is a superacid that, in terms of corrosiveness, is trillions of times stronger than pure sulfuric acid when measured by its Hammett acidity function.
Carborane acids H(CXB 11 Y 5 Z 6) (X, Y, Z = H, Alk, F, Cl, Br, CF 3) are a class of superacids, [1] some of which are estimated to be at least one million times stronger than 100% pure sulfuric acid in terms of their Hammett acidity function values (H 0 ≤ –18) and possess computed pK a values well below –20, establishing them as some of the strongest known Brønsted acids.
As indicated by its acid dissociation constant, sulfuric acid is a strong acid: H 2 SO 4 → H 3 O + + HSO − 4 K a1 = 1000 (pK a1 = −3) The product of this ionization is HSO − 4, the bisulfate anion. Bisulfate is a far weaker acid: HSO − 4 + H 2 O → H 3 O + + SO 2− 4 K a2 = 0.01 (pK a2 = 2) [20] The product of this second ...
A strong superacid of this kind is fluoroantimonic acid. Another group of superacids, the carborane acid group, contains some of the strongest known acids. Finally, when treated with anhydrous acid, zeolites (microporous aluminosilicate minerals) will contain superacidic sites within their pores.
Trifluoroacetic acid is a strong acid. [12] TFA is harmful when inhaled, causes severe skin burns and is toxic for aquatic organisms even at low concentrations. Skin burns are severe, heal poorly and can be necrotic. Vapour fumes have an LC 50 of 10.01 mg/L, tested on rats over 4 hours.
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 pK a = 3.18), [10] in contrast to corresponding solutions of the other hydrogen halides, which are strong acids (pK a < 0).