Chemical formulas condensed structural formula

The chemical synonyms and identification numbers for wood creosote, coal tar creosote, and coal tar are listed in Tables 4-1 through 4-3. Coal tar pitch is similar in composition to coal tar creosote and is not presented separately. Coal tar pitch volatiles are compounds given off from coal tar pitch when it is heated. The volatile component is not shown separately because it varies with the composition of the pitch. Creosotes and coal tars are complex mixtures of variable composition containing primarily condensed aromatic ring compounds (coal-derived substances) or phenols (wood creosote). Therefore, it is not possible to represent these materials with a single chemical formula and structure. The sources, chemical properties, and composition of coal tar creosote, coal tar pitch, and coal tar justify treating these materials as a whole. Wood creosote is discussed separately because it is different in nature, use, and risk. 

Using condensed structural formulas, write a balanced chemical equation for each of the following reactions (a) hydrogenation of cyclohexene (b) addition of H2O to trans-2-pentene using H2SO4 as a catalyst (two products) (c) reaction of 2-chloropropane with benzene in the presence of AICI3. 

Write a balanced chemical equation using condensed structural formulas for the saponification (base hydrolysis) of (a) methyl propionate, (b) phenyl acetate. 

Condensed structural formula (Section 1.7B) A chemical formula written using letters of the elemental symbols for the atoms involved, listed in sequence for the connections of the central chain of atoms and without showing the bonds between them. In organic compounds, all of the substituent atoms that are bonded to a given carbon atom are written immediately after the symbol for that carbon atom, then the next carbon atom in the chain is written, and so on. 

Representation of Chemical Compounds 21 Structure diagram Condensed formula... 

Two-Dimensional Representation of Chemical Structures. The lUPAC standardization of organic nomenclature allows automatic translation of a chemical s name into its chemical stmcture, or, conversely, the naming of a compound based on its stmcture. The chemical formula for a compound can be translated into its stmcture once a set of semantic rules for representation are estabUshed (26). The semantic rules and their appHcation have been described (27,28). The inverse problem, generating correct names from chemical stmctures, has been addressed (28) and explored for the specific case of naming condensed benzenoid hydrocarbons (29,30). 

In a balanced chemical equation (commonly called a chemical equation ), the same number of atoms of each element appears on both sides of the equation, chemical equilibrium A dynamic equilibrium between reactants and products in a chemical reaction, chemical formula A collection of chemical symbols and subscripts that shows the composition of a substance. See also condensed structural formula empirical formula,- molecular formula structural formula. 

C21-0053. Three phosphate anions can condense to form a ring whose chemical formula Is P3 Og. Determine the Lewis structure and draw a ball-and-stick model of this anion. 

The oldest publications in this field are mainly concerned with the hydrolysis of hexachlorodisilane and octachlorotrisilane166,167, 417, 4,8> S15 xhe chemical and physical properties of the compounds are well described, but it now seems necessary to revise the postulated structural formulas and the nomenclature (e.g. siliconoxalic acid and siliconmesocalic acid). Exact structural formulae have yet to be ascertained, but the structure certainly includes Si 2 and Si 3 units condensed with Si-O-Si bonds. Depending upon the reaction conditions and water content, more or fewer OH groups will be found in the compound. However, in no case are the double bonds Si = Sid or Si = 0, which had been postulated in earlier publications, found to be present. 

Amino acids of the general form, 1, are the monomeric molecules which are condensed to form the polypeptide chains of the fibrous and globular proteins. The naturally occurring molecules are the L-enantiomers, shown in 1 for chemical formulae see Fig. 19.1. D-amino acids can be synthesized and the individual L- or D-amino acids or the D,Lrracemates can be crystallized. All the common amino acids have been studied by neutron or X-ray crystal structure analysis (see Thble 14.1), in the anhydrous or hydrate forms, as hydrochlorides or hydrochloride hydrates. 

Write condensed chemical formulas to represent the Lewis structures in parts (a) through (j) of problem 52. (For example, 2-propanol can he described as CH3CH(0H)CH3.)... 

Just as an atom is the smallest part of an element, a single element is the smallest portion of a chemical compound that can be encountered. Chemical compounds are made up of two or more elements that have bonded covalently or ionically. Chemical compounds are represented by formulae, much like elements are represented by symbols. According to the Condensed Chemical Dictionary, a formula is a written representation, using symbols, of a chemical entity or relationship. There are three types of chemical formulae empirical, molecular, and structural. 

ABSTRACT. Based on the nomenclature report of the lUCr (1990) the concepts of isopointal, isoconfigurational, Isotypic and homeotypic structures are described and illustrated by several examples. The notation proposed In this report for the crystal - chemical formulae is also developed, including the symbologies for close packings which are not closest, and for the condensation process of the structural units. 

You should be able to draw chemical formulas that show all of the valence electrons in a molecule (Lewis structures), using lines for bonds and dots to show unshared electrons. You should be proficient in representing structures as dash structural formulas, condensed structural formulas, and bond-line structural formulas. In particular, the more quickly you become skilled at using and interpreting bondline formulas, the faster you will be able to process structural information in organic chemistry. You have also learned about resonance structures, the use of which wiU help us in understanding a variety of concepts in later chapters. 

Structures shown in the following scheme are two different isomers which really represent two different compounds. To convert one isomer into another it is necessary to break and reform chemical bonds by a chemical reaction. The isomers are represented in two ways, by connectivity structural formula in which all the interatomic bonds and atomic symbols are shown and also by the condensed formula where the chains between the CH3 and CH2 groups are drawn. Such more practical formulas are mostly used in organic chemistry. The particular groups in the chain have special names such as methylene group for CH2 and methyl group for CH3. 

Structural formula of thiamin and its chemical properties. (A) Structural formula of thiamin. (B) The C-2 carbon of the thiazolium moiety can lose its proton yielding a highly nucleophilic ylide analogous to cyanide. (C) Cyanide and thiamin catalysed condensation of benzaldehyde to benzoin. (D) Oxydation of thiamin in strongly alkaline medium yields the highly fluorescent thiochrome, a property used for the experimental determination of thiamin and its phosphate esters. 

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