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  2. Acid value - Wikipedia

    en.wikipedia.org/wiki/Acid_value

    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 ...

  3. pH - Wikipedia

    en.wikipedia.org/wiki/PH

    In chemistry, pH (/ piːˈeɪtʃ / pee-AYCH), also referred to as acidity or basicity, historically denotes " potential of hydrogen " (or "power of hydrogen"). [1] It is a logarithmic scale used to specify the acidity or basicity of aqueous solutions.

  4. Acidity function - Wikipedia

    en.wikipedia.org/wiki/Acidity_function

    An acidity function is a measure of the acidity of a medium or solvent system, [1][2] usually expressed in terms of its ability to donate protons to (or accept protons from) a solute (Brønsted acidity). The pH scale is by far the most commonly used acidity function, and is ideal for dilute aqueous solutions.

  5. Acid strength - Wikipedia

    en.wikipedia.org/wiki/Acid_strength

    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 ...

  6. Acid dissociation constant - Wikipedia

    en.wikipedia.org/wiki/Acid_dissociation_constant

    v. t. e. In chemistry, an acid dissociation constant (also known as acidity constant, or acid-ionization constant; denoted ⁠ ⁠) is a quantitative measure of the strength of an acid in solution. It is the equilibrium constant for a chemical reaction. known as dissociation in the context of acid–base reactions. The chemical species HA is an ...

  7. Buffer solution - Wikipedia

    en.wikipedia.org/wiki/Buffer_solution

    A buffer solution is a solution where the pH does not change significantly on dilution or if an acid or base is added at constant temperature. [1] Its pH changes very little when a small amount of strong acid or base is added to it. Buffer solutions are used as a means of keeping pH at a nearly constant value in a wide variety of chemical ...

  8. Hammett acidity function - Wikipedia

    en.wikipedia.org/wiki/Hammett_acidity_function

    The Hammett acidity function (H 0) is a measure of acidity that is used for very concentrated solutions of strong acids, including superacids.It was proposed by the physical organic chemist Louis Plack Hammett [1] [2] and is the best-known acidity function used to extend the measure of Brønsted–Lowry acidity beyond the dilute aqueous solutions for which the pH scale is useful.

  9. Gutmann–Beckett method - Wikipedia

    en.wikipedia.org/wiki/Gutmann–Beckett_method

    In chemistry, the Gutmann–Beckett method is an experimental procedure used by chemists to assess the Lewis acidity of molecular species. Triethylphosphine oxide (Et3PO, TEPO) is used as a probe molecule and systems are evaluated by 31 P-NMR spectroscopy. In 1975, Viktor Gutmann [de] used 31 P-NMR spectroscopy to parameterize Lewis acidity of ...