Oxidation reduction reactions, 680. See

Metals react with nonmetals. These reactions are oxidation-reduction reactions. (See Chapters 4 and 18). Oxidation of the metal occurs in conjunction with reduction of the nonmetal. In most cases, only simple compounds will form. For example, oxygen, 02, reacts with nearly all metals to form oxides (compounds containing O2-). Exceptions are the reaction with sodium where sodium peroxide, Na202, forms and the reaction with potassium, rubidium, and cesium where the superoxides, K02, Rb02, and Cs02 form. 

Nicotinic acid and nicotinamide are precursors of the coenzymes NAD+ and NADP+, which play a vital role in oxidation-reduction reactions (see Box 7.6), and are the most important electron carriers in intermediary metabolism (see Section 15.1.1). We shall look further at the chemistry of NAD+ and NADP+ shortly (see Box 11.2), but note that, in these compounds, nicotinamide is bound to the rest of the molecule as an A-pyridinium salt. 

Riboflavin (vitamin B2) is a component of flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), coenzymes that play a major role in oxidation-reduction reactions (see Section 15.1.1). Many key enzymes involved in metabolic pathways are actually covalently bound to riboflavin, and are thus termed flavoproteins. 

A reaction in which the oxidation number of an element is increased. Examples (1, 2, 3) 2 Mg(s) + 02(g) - 2 MgO(s) (2, 3) Mg(s) - Mg2+(s) + 2e". oxidation number The effective charge on an atom in a compound, calculated according to a set of rules (Toolbox K.l). An increase in oxidation number corresponds to oxidation, and a decrease, to reduction, oxidation-reduction reaction See redox reaction. oxidation state The actual condition of a species with a specified oxidation number. 

Derivatives of porphyrins are coenzymes in a number of oxidation-reduction reactions (see chapters 10, 14, and 15). 

Cyano metal complexes undergo a variety of oxidation-reduction reactions. One of the most studied is the fast self-exchange reaction of the [Fe(CN)4] /" anions information from this research was instrumental in establishing the outer-sphere mechanism (see Outer-sphere Reaction) for transition metal oxidation-reduction reactions (see Electrochemistry Applications in Inorganic Chemistry). The nature... 

For this type of combination reaction, each element goes from an uncombined state, where its oxidation state is zero, to a combined state in a compound, where its oxidation state is not zero. Thus reactions of this type are oxidation-reduction reactions (see Section 4-5). 

This reaction produces the flame of the common laboratory burner and is also used to heat most homes in the United States. Recall that we originally classified this reaction as an oxidation-reduction reaction. Thus we can say that the reaction of methane with oxygen is both an oxidation-reduction reaction and a combustion reaction. Combustion reactions, in fact, are a special class of oxidation-reduction reactions (see Figure 8.7). 

H3N -f Ba3 H3NBCl3 in which NH3 is the base (donor) and BCI3 the acid (acceptor). The Lewis theory establishes a relationship between acid-base reactions and oxidation-reduction reactions. See HSAB principle. See also aqua aod hy-droxoacid oxoacid. 

II. Oxidation-Reduction Reactions (see figure). It was discovered that the easily oxidisable IrCl(COXPh P)2 (3) reacts at room temperature in solution with mercury compounds (2) as follows ... 

Aquatic organisms, especially single-celled microorganisms, are very much involved in chemical transitions in the hydrosphere. Most of them are oxidation-reduction reactions (see Section 3.7). 

Fuel cells are based on oxidation-reduction reactions (see Section 4.9). The most common type of fuel cell—called the hydrogen-oxygen fuel ceU— is based on the reaction between hydrogen and oxygen ... 

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