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Chemical structure of the vinyl functional group. In organic chemistry , a vinyl group (abbr. Vi ; [ 1 ] IUPAC name : ethenyl group [ 2 ] ) is a functional group with the formula −CH=CH 2 . It is the ethylene (IUPAC name: ethene) molecule ( H 2 C=CH 2 ) with one fewer hydrogen atom.
A chemical equation is the symbolic representation of a chemical reaction in the form of symbols and chemical formulas.The reactant entities are given on the left-hand side and the product entities are on the right-hand side with a plus sign between the entities in both the reactants and the products, and an arrow that points towards the products to show the direction of the reaction. [1]
The numbers 200-900 would be confused easily with 22 to 29 if they were used in chemistry. khīlioi = 1000, diskhīlioi = 2000, triskhīlioi = 3000, etc. 13 to 19 are formed by starting with the Greek word for the number of ones, followed by και (the Greek word for 'and'), followed by δέκα (the Greek word for 'ten').
It is one of three structural isomers with the molecular formula C 5 H 12, the others being pentane (n-pentane) and neopentane (2,2-dimethylpropane). Isopentane is commonly used in conjunction with liquid nitrogen to achieve a liquid bath temperature of −160 °C.
Typically, a number of equally valid SMILES strings can be written for a molecule. For example, CCO, OCC and C(O)C all specify the structure of ethanol. Algorithms have been developed to generate the same SMILES string for a given molecule; of the many possible strings, these algorithms choose only one of them.
Chemical formula (no prefix). This is the only sublayer that must occur in every InChI. Numbers used throughout the InChI are given in the formula's element order excluding hydrogen atoms. For example, "/C10H16N5O13P3" implies that atoms numbered 1–10 are carbons, 11–15 are nitrogens, 16–28 are oxygens, and 29–31 are phosphorus. [11]
The Avogadro constant, commonly denoted N A [1] or L, [2] is an SI defining constant with an exact value of 6.022 140 76 × 10 23 mol −1 (reciprocal moles). [3] [4] It is this defined number of constituent particles (usually molecules, atoms, ions, or ion pairs—in general, entities) per mole and used as a normalization factor in relating the amount of substance, n(X), in a sample of a ...
Jean Beguin (1550–1620) was an iatrochemist noted for his 1610 Tyrocinium Chymicum (Begin Chemistry), which many consider to be one of the first chemistry textbooks. In the 1615 edition of his textbook, Beguin made the first-ever chemical equation or rudimentary reaction diagrams, showing the results of reactions in which there are two or more reagents. [1]