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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.
Strong acids, such as sulfuric or phosphoric acid, have large dissociation constants; weak acids, such as acetic acid, have small dissociation constants. The symbol K a , used for the acid dissociation constant, can lead to confusion with the association constant , and it may be necessary to see the reaction or the equilibrium expression to ...
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. Examples of strong acids are hydrochloric acid , perchloric acid , nitric acid and sulfuric ...
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 ...
The acid number is a measure of the number of carboxylic acid groups (−C (=O)OH) in a chemical compound, such as a fatty acid, or in a mixture of compounds. [2] In other words, it is a measure of free fatty acids (FFAs) present in a substance. In a typical procedure, a known amount of sample dissolved in an organic solvent (often isopropanol ...
An example of an alkalimetric titration involving a strong acid is as follows: H 2 SO 4 + 2 OH − → SO 4 2-+ 2 H 2 O. In this case, the strong acid (H 2 SO 4) is neutralized by the base until all of the acid has reacted. This allows the viewer to calculate the concentration of the acid from the volume of the standard base that is used.
A strong acid, such as hydrochloric acid, at concentration 1 mol dm −3 has a pH of 0, while a strong alkali like sodium hydroxide, at the same concentration, has a pH of 14. Since pH is a logarithmic scale, a difference of one in pH is equivalent to a tenfold difference in hydrogen ion concentration.
Methyl orange is a pH indicator frequently used in titration because of its clear and distinct color variance at different pH values. Methyl orange shows red color in acidic medium and yellow color in basic medium. Because it changes color at the p Ka of a mid strength acid, it is usually used in titration of strong acids in weak bases that ...