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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.
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.
A Lewis base is often a Brønsted–Lowry base as it can donate a pair of electrons to H +; [11] the proton is a Lewis acid as it can accept a pair of electrons. The conjugate base of a Brønsted–Lowry acid is also a Lewis base as loss of H + from the acid leaves those electrons which were used for the A—H bond as a lone pair on the ...
On the other hand, if a chemical is a weak acid its conjugate base will not necessarily be strong. Consider that ethanoate, the conjugate base of ethanoic acid, has a base splitting constant (Kb) of about 5.6 × 10 −10, making it a weak base. In order for a species to have a strong conjugate base it has to be a very weak acid, like water.
H 2 O is a base because it accepts a proton from CH 3 COOH and becomes its conjugate acid, the hydronium ion, (H 3 O +). [9] The reverse of an acid–base reaction is also an acid–base reaction, between the conjugate acid of the base in the first reaction and the conjugate base of the acid.
Caubère defines superbases as "bases resulting from a mixing of two (or more) bases leading to new basic species possessing inherent new properties. The term superbase does not mean a base is thermodynamically and/or kinetically stronger than another, instead it means that a basic reagent is created by combining the characteristics of several ...
Free energy relationships establish the extent at which bond formation and breakage happen in the transition state of a reaction, and in combination with kinetic isotope experiments a reaction mechanism can be determined. Free energy relationships are often used to calculate equilibrium constants since they are experimentally difficult to ...
Specific and general catalysis is also found in base catalysed reactions and base Brønsted equation also exists with constant β. The Brønsted equation gives information about a reaction mechanism. Reactions that have low values for proportionality constants α or β are considered to have a transition state closely resembling the reactant ...