Halogens oxoanions

Oxidation A half-reaction in which there is an increase in oxidation number, 88 chromium, 548 electrolysis and, 498 fluorine, 557 halogens, 557-558 oxoacids, 568-570 oxoanions, 568-570 species strength, 506-507q transition metals, 546t zinc, 86-87... 

Transplutonium(VI) complexes aqua,3,1220 carbonates, 3, 1220 carboxylates chelating, 3, 1220 halogens, 3,1220 monocarboxylates, 3,1220 nitrato, 3,1220 oxides, 3,1220 oxoanions, 3, 1220 Transport cations... 

Some elements—particularly the halogens—form more than two kinds of oxoanions. The name of the oxoanion with the smallest number of oxygen atoms is formed by adding the prefix hypo- to the -ite form of the name, as in the hypochlorite ion, CIO-. The oxoanion with the most oxygen atoms is named with the prefix per- added to the -ate form of the name. An example is the perchlorate ion, C104-. The rules for naming polyatomic ions are summarized in Appendix 3A and common examples are listed in Table D.l. 

With four oxoanions in the family (usually a halogen bonded to O), as Figure 2.17 shows ... 

Let s examine the compounds the halogens form with hydrogen and with each other, as well as their oxides, oxoanions, and oxoacids. 

Halogen Oxides, Oxoacids, and Oxoanions The Group 7A(17) elements form many oxides that are powerful oxidizing agents. Dichlorine monoxide (CI2O), chlorine dioxide (CIO2, with an unpaired electron and Cl in the unusual -t-4 oxidation state), and dichlorine heptaoxide (CLOy) are important examples. 

The halogen oxoacids and oxoanions are produced by reaction of the halogens and their oxides with water. Most of the oxoacids are stable only in solution. Table 14.3 (next page) shows ball-and-stick models of the acids in which each atom has its lowest formal charge note that H is bonded to O. (We ll discuss factors that determine the relative strengths of the halogen oxoacids in Chapter 18.)... 

Salts of the halogen oxoanions decompose to hahdes and oxygen upon heating ... 

Transplutonium(VI) complexes aqua,1220 carbonates, 1220 carboxylates chelating, 1220 halogens, 1220 monocarboxyiates, 1220 nitrato, 1220 oxides, 1220 oxoanions, 1220 Triethanolamine alkali metal complexes, 23 Triethylamine, 2,2, 2"-trimethoxy-alkali metal complexes, 24 Trimolybdates, 1032 Trithioarsenates, 249 1,3,6,2-Trithioarsocane, 2-chloro-, 249 Trithioraolybdates, 1378 Trivanadates, 1027... 

Fluorine has an oxidation number of -1 in all its compounds. Other halogens (Cl, Br, and 1) have negative oxidation numbers when they occur as hahde ions in their compounds. When combined with oxygen— for example in oxoacids and oxoanions (see Section 2.7)— they have positive oxidation numbers. 

Discuss key features of Group 7A(17), understand how intermolecular forces and outer electron configuration account for physical and chemical properties, and descrihe the hydrogen halides, interhalogen compounds, and halogen oxides, oxoacids, and oxoanions ( 14.8) (EPs 14.66-14.73)... 

Another point to notice in Table 18.2 is that any given halogen oxoacid is a better oxidizing agent—that is, has a higher standard reduction potential—than its corresponding oxoanion. Take the HOCl/OCH case as typical. Equation (18.28) shows the half-equation for hypochlorous acid in acid solution ... 

Of the rare earth compounds with halogen-containing oxoanions, the perbro-mates have not yet been prepared and the chlorites and chlorates have been studied only sporadically the other bromates and the iodates, perchlorates, and periodates are widely discussed in the literature. A comprehensive review on the oxohalogen compounds of Cl, Br, and I with the rare earths has appeared in the late 1970 s (Gmelin, 1977, 1978). The oxofluorides have been discussed in an earlier volume (Gmelin, 1976) only the ROF and related types of compounds are known and they fall outside the scope of this review. The TG and DTA data on rare earth perchlorates and iodates are discussed in Solomosi s comprehensive book (1977) on the structure and stability of solid halogen oxoacid compounds however, many important papers have been published since its appearance. 

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