Formulae and structure

Crystalline solids have atoms, ions, or molecules packed in regular geometric arrays, with the simplest repeating structural unit called the unit cell. Some of the common crystal geometries are described in this section. In addition, we will consider the role of the relative sizes of the components in determining structures. Use of a model kit, such as the one available from ICE, facilitates the study of these structures. 

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The names, formulae and structures of these alkaloids are given in the following table. The esters of tropine or -tropine are known as tropeines or -tropeines respectively. The first eleven items in the table are sometimes called the solanaceous alkaloids, but they are not the only alkaloids, or even the only type of alkaloid, found in the botanical family Solanaceas. They are also sometimes referred to as the mydriatic alkaloids though other alkaloids also exert this action. 

If the sample consists of atoms of one element, the mass spectrum gives the isotopic distribution of the sample. The relative molar masses of the isotopes can be determined by comparison with atoms of carbon-12. If the sample is a compound, the formula and structure of the compound can be determined by studying the fragments. For example, the + 1 ions that CH4 could produce are CH4, CH3+, CH, CFI4, C+, and H4. Some of the particles that strike the detector are those that result when the molecule simply loses an electron (for example, to produce Cl I4+ from methane) ... 

In contrast to the carbides and nitrides, there are a large variety of formulas and structure types for borides (from M4B to MB 5). Although it is possible to establish a comparison between metal-rich borides and carbides, B-rich borides have no counterpart in the carbides. 

VII. Appendix Ligand Abbreviations, Formulae, and Structures References... 

Information regarding the chemical identity of hydrogen sulfide is located in Table 3-1. This information includes synonyms, chemical formula and structure, and identification numbers. 

Fig. 2.12. Relationship between sample domain and signal domain in element analysis (a) and structure analysis (b). The representation in the sample domains is shown in different forms, as a block diagram and a list in case of (a) and as constitution formula and structure matrix, respectively, in case (b)...

Figure 2.3. Capillary gas chromatogram of Si(OCH3)4 (3M) (a) after hydrolysis/ condensation with H20 (1.8 M) and HC1 (0.05 M) showing assignments of molecular formulas and structures and (b) with H20 (1.5 M) and catalysis conditions shown. For (a), linear and cyclical structures are indicated along the x-axis. All plots illustrate relative concentrations of species (y-axis) as a function of GC column retention time (x-axis). Higher mass species (e.g., hexamers (Si6) and pentamers (Si5)) demonstrate longer retention times. [Reprinted from Ref. 72, with permission.]...

Every once in a while you may run into an organic chemistry problem in Section II, on writing equations. An example is Write an equation that describes burning methanol in air. You would need to know the chemical formula and structural formula of methanol in order to do this problem. Writing organic reactions is covered in more detail in the chapter entitled Writing and Predicting Chemical Reactions. ... 

Adams-Nickerson color space, 7 320 Adapalene, 25 789 Adapress, molecular formula and structure, 5 128t Adaptive control system, 20 698 Adaptive sampling techniques, 26 1016-1019... 

Additive toxic effects, 25 213—214 Adducts, of vinyl chloride, 25 632 Adenine, 8 174. See also ADP entries Adenocard, molecular formula and structure, 5 98t... 

Aldactazide, molecular formula and structure, 5 165t Aldactone, 5 166... 

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