Chemical substances oxidizing agents

Perkin s professor, August Wilhelm Hofmann, had declared to his students that the first chemist to synthesize quinine would become wealthy and famous. The world desperately needed quinine to treat malaria, but the only source of it was the cinchona tree, which grew in South America. Hofmann had worked on substances isolated from petroleum, and he d found that the chemical composition of some of these compounds was like that of quinine, except for the fact that they lacked oxygen. It therefore occurred to him that, by treating coal-tar extracts with chemicals called oxidizing agents, he could add the required oxygen to the molecule. 

Suong oxidizers have more potential incompatibilities than perhaps any other chemical group (with the exception of water reactive substances). It is safe to assume that they should not be stored or mixed with any other material except under carefully controlled conditions. Common oxidizing agents listed in decreasing order of oxidizing strength include ... 

The chemical mechanism rests on the effect of intervening redox systems (see Section 13.6). Here intermediate reactants such as species on a cathode surface, species on an anode surface, or reducing and oxidizing agents in the solution layer next to the electrode are first produced electrochemicaUy from solution components. The further interaction of these reactants with the organic substance is purely chemical in character, for example, following a reaction... 

Depending on the context, oxidation can either refer to (a) a reaction in which oxygen combines chemically with another substance or (b) any reaction in which electrons are transferred. For the latter definition, oxidation and reduction always occur simultaneously (redox reactions), and the substance that gains electrons is termed the oxidizing agent. Electrons might also be displaced within a molecule without being completely transferred away from it. 

Reactive chemicals are those that tend to undergo rapid or violent reactions under certain conditions. Such substances include those that react violently or form potentially explosive mixtures with water, such as some of the common oxidizing agents (Table 1.6). Explosives (Sudweeks et al., 1983 Austin, 1984) constitute another class of reactive chemicals. For regulatory purposes, those substances are also classified as reactive that react with water, acid, or base to produce toxic fumes, particularly hydrogen sulfide or hydrogen cyanide. 

The chemical stability of resins may be degraded due to chemical interactions with oxidizing agents. The latter interact with CH2 groups and gradually lead to the destruction of the matrix. The main oxidizing substances are... 

Tantalum is not resistant to substances that can react with the protective oxide layer. The most aggressive chemicals are hydrofluoric acid and acidic solutions containing fluoride. Fuming sulfuric acid, concentrated sulfuric acid above 175°C, and hot concentrated alkali solutions destroy the oxide layer and, therefore, cause the metal to corrode. In these cases, the corrosion process occurs because the passivating oxide layer is destroyed and the underlying tantalum reacts with even mild oxidizing agents present in the system. 

In the early days of organic chemistry, alkenes were described as unsaturated because, in contrast to the saturated alkanes, they were found to react readily with substances such as halogens, hydrogen halides, oxidizing agents, and so on. Therefore, the chemical affinity of alkenes was regarded as unsatisfied or unsaturated. (Also see Section 1-11.)... 

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