Group oxoacids/oxoanions

The group oxidation state of +5 is too high to allow the formation of simple ionic salts even for Nb and Ta, and in lower oxidation states the higher sublimation energies of these heavier metals, coupled with their ease of oxidation, again militates against the formation of simple salts of the oxoacids. As a consequence the only simple oxoanion salts are the sulfates of vanadium in the oxidation states +3 and +2. These can be crystallized from aqueous solutions as hydrates and are both strongly... 

The properties of alkali metal salts of most oxoacids depend on the oxoanion present and not on the cation thus we tend to discuss salts of oxoacids under the appropriate acid. However, we single out the carbonates and hydrogencarbonates because of their importance. Whereas Li2C03 is sparingly soluble in water, the remaining carbonates of the group 1 metals are very soluble. 

Further, there is little difference in energy between the various oxidation state species of sulfur, a fact that is doubtless involved in the complicated oxoacid and oxoanion chemistry of sulfur. We have already discussed some aspects of the aqueous solution chemistry of the group 16 elements ... 

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 reactions of the halogens and their oxides with water. Most of the oxoacids are stable only in solution. Table 14.3 shows ball-and-stick models of the acids in which each atom has its lowest formal charge note the formulas, which emphasize that H is bonded to O. The hypohalites (XO ), halites (XO2 ), and halates (XOj ) are oxidizing agents formed by aqueous disproportionation reactions [see the Group 7A(17) Family Portrait, reaction 2]. You may have heated solid alkali chlorates in the laboratory to form small amounts of O2 ... 

Discuss key features of Group 5A(15), especially patterns in oxidation state, oxide acidity, and hydride and halide structures and describe the nitrogen and phosphoms oxides, oxoacids, and oxoanions ( 14.6) (EPs 14.46-14.56)... 

Table 12.4 shows the rich variety of oxoanions of sulfur that are possible. In fact, few of these oxoacids are known in the undissociated state. Apart from some of the polythionic acids, no oxoacid in which sulfur has an oxidation number <6 is stable, even in concentrated aqueous solution, and only sulfuric acid and its dimer disulfuric acid exist as free acids at room temperature. The derivative, obtained by replacing one of the —OH groups of sulfuric acid by an —SH group, thiosulfuric acid, is stable only below 0 °C. 

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