Classification of inorganic substances

The classification of inorganic substances in waters into electrolytes, non-electrolytes, cations and anions is only formal grouping and not necessarily exact, since a given element can occur in water both in ionic and nonionic forms simultaneously, including different complex forms which will be discussed in following sections [1]. 

With Wohler s work, it was apparent that no vital force other than skill and knowledge was needed to make organic chemicals in the laboratory. Today the branch of chemistry that deals with carbon compounds, oi nic chemistry, does not imply that these compounds must originate from living matter. A few special kinds of carbon compounds (e.g., carbon oxides, metal carbides, and metal carbonates) are excluded from the organic classification because their chemistry is more closely related to that of inorganic substances. 

E.H. Hurst s overview introduced several themes pursued by other chemical industry speakers. The Dow Chemical Company s E.H. Blair analyzed the problem of setting priorities for testing the 55,000 existing chemicals listed in the TSCA inventory for their effects on health and the environment. Resources for such testing are not unlimited. A systematic classification was made of these substances by production volume. The 9.5% of these substances which account for 99.9% of reported production were divided further into categories such as organic, inorganic, and polymeric. 

The industrial stream to be treated, the feed, will not be an analytical grade solute dissolved in water, but often contains several known and unknown substances, both organic and inorganic. To be able to make an initial selection of possible solvents, it is necessary to make a classification of the individual substances present in the feed and of the groups of substances with chemical similarities, for instance, paraffins, aromatics, salts, or others. The following questions have to be answered ... 

MINERALOGY. The science of mineralogy is concerned with the formation, occurrence, properties, composition, and classification of minerals. Vnrinus definitions of a mineral have been proposed. Possibly, the most acceptable may be. "a naturally occurring inorganic substance, usually crystalline, possessing a relatively definite chemical composition and physical characteristics. It should be pointed out that some naturally formed organic substances, particularly of an economic resource nature, are sometimes classified as minerals. 

Huheey (1983) (see Section A.3 of the Appendix) gives in Appendix J a good, concise summary of the rules for inorganic nomenclature. For the classification of substances according to structural type, see the books listed in Section A.6. Wells (1984) is specially recommended. 

The predicted and known classifications of skin corrosion potential are given in Table 18.7. Predictions of corrosion potential made by the QSAR in step 1 are made only for the 36 single chemicals that are organic liquids, since the domain of the QSAR excludes inorganic substances,... 

When one considers the incredible number of chemical reactions that are possible, it becomes apparent why a scheme that systemizes a large number of reactions is so important and useful. Indeed, classification of reaction types is important in all areas of chemistry, and a great deal of inorganic chemistry can be systematized or classified by the broad types of compounds known as acids and bases. Many properties and reactions of substances are understandable, and predictions can often be made about their reactions in terms of acid-base theories. In this chapter, we will describe the most useful acid-base theories and show their applications to inorganic chemistry. However, water is not the only solvent that is important in inorganic chemistry, and a great deal of chemistry has been carried out in other solvents. In fact, the chemistry of nonaqueous solvents is currently a field of a substantial amount of research in inorganic chemistry, so some of the fundamental nonaqueous solvent chemistry will be described in this chapter. 

Classification according to type involves the relative proportions of both the inorganic substances and the different organic substances. Because only the organic material is altered by metamorphic processes, rank... 

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