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Also acid ionization constant or acidity constant. A quantitative measure of the strength of an acid in solution expressed as an equilibrium constant for a chemical dissociation reaction in the context of acid-base reactions. It is often given as its base-10 cologarithm, p K a. acid–base extraction A chemical reaction in which chemical species are separated from other acids and bases. acid ...
Chemistry (from Egyptian kēme (chem), meaning "earth" [1]) is the physical science concerned with the composition, structure, and properties of matter, as well as the changes it undergoes during chemical reactions. [2] Below is a list of chemistry-related articles in alphabetical order.
In the analysis of the molecular formula of organic molecules, the degree of unsaturation (DU) (also known as the index of hydrogen deficiency (IHD), double bond equivalents (DBE), or unsaturation index [1]) is a calculation that determines the total number of rings and π bonds. A formula is used in organic chemistry to
A mnemonic is a memory aid used to improve long-term memory and make the process of consolidation easier. Many chemistry aspects, rules, names of compounds, sequences of elements, their reactivity, etc., can be easily and efficiently memorized with the help of mnemonics.
A gradient-index lens with a parabolic variation of refractive index (n) with radial distance (x). The lens focuses light in the same way as a conventional lens. If the refractive index of a medium is not constant but varies gradually with the position, the material is known as a gradient-index (GRIN) medium and is described by gradient index ...
The first scientific journal specifically in the field of physical chemistry was the German journal, Zeitschrift für Physikalische Chemie, founded in 1887 by Wilhelm Ostwald and Jacobus Henricus van 't Hoff. Together with Svante August Arrhenius, [11] these were the leading figures in physical chemistry in the late 19th century and early 20th ...
Butane (C 4 H 10) has two different structural isomers: n-butane, with a linear structure of four carbon atoms, and isobutane, with a branched structure.The chemical graph for n-butane is a four-vertex path graph, and the chemical graph for isobutane is a tree with one central vertex connected to three leaves.
The Hosoya index is the first topological index recognized in chemical graph theory, and it is often referred to as "the" topological index. [6] Other examples include the Wiener index , Randić's molecular connectivity index , Balaban’s J index , [ 7 ] and the TAU descriptors.