Oxoacids and Oxoanions

Chloric and bromic acids can be prepared similarly by the action of H2SO4 on the appropriate barium salts. Iodic acid, by contrast, is conveniently prepared by hydrolysis of readily available I2O5  

The mechanism is expected to be rather simple water attacks one of the pentavalent iodine centers, with iodate (103 ) acting as the leaving group  

As mentioned above, iodic acid can be isolated as a pure solid. It consists of discrete HIO3 molecules. What would you predict for the molecular structure based on VSEPR considerations  

Acidification of a NaC102 solution with strong acid results in the formation of CIO2  

The CIO2 arises via rapid disproportionation of chlorous acid (HCIO2), which forms initially, under strongly acidic conditions. A more insightful way to write the reaction is  

The acid equilibrium constants of the oxoacids of the halogens are hsted in Table 21.5. Notice that the value of K, increases with 

These trends are general ones, observed with other oxoacids of the nonmetals. Recall, for example, that nitric acid, HNO3 (oxid. no. N = +5), is a strong acid, completely ionized in water. In contrast, nitrous acid, HNO2 (oxid. no. N = +3),isaweakacid(JCa = 6.0 X lO ). The electronegativity effect shows up with the strengths of the oxoacids of sulfur and selenium  

Trends in acid strength can be explained in terms of molecular structure. In an oxoacid molecule, the hydrogen atom that dissociates is bonded to oxygen, which in turn is bonded to a nonmetal atom, X. The ionization in water of an oxoacid H—O—X can be represented as 

For a proton, with its +1 charge, to separate from the molecule, the electron density around the oxygen should be as low as possible. This will weaken the O—H bond and favor ionization. The electron density around the oxygen atom is decreased when— 

STRATEGY AND SOLUTION Reread the discussion on writing Lewis structures in Chapter 7. 

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A comprehensive treatment of the oxoacids and oxoanions of P is inappropriate but selected examples have been chosen to illustrate... 

Many of the reactions of oxoacids and oxoanions involve oxidation and reduction. There are certain general principles that apply, regardless of the particular species involved. 

The oxoacids and oxoanions of phosphorus are among the most heavily manufactured chemicals. Phosphate fertilizer production consumes two-thirds of all the sulfuric acid produced in the United States. 

Klaning, U. K., K. Sehested, and T. Wolff, Ozone Formation in Laser Flash Photolysis of Oxoacids and Oxoanions of Chlorine... 

Oxoacids and Oxoanions The names of oxoanions and their parent acids can be deter- ... 

Various generic names have been used for oxoacids and oxoanions. Because there are many of them, it is difficult to define the terms unambiguously and consistently. But the following statements may be helpful. 

Note that we usually omit the prefrx mono- when there is only one H in the anion. Figure 2.12 summarizes the nomenclature for the oxoacids and oxoanions, and Table 2.6 gives the names of the oxoacids and oxoanions that contain chlorine. 

Name the following oxoacid and oxoanion (a) HBrO, (b) HSOJ. 

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 ... 

Nitrogen Oxoacids and Oxoanions The two common nitrogen oxoacids are nitric acid and nitrous acid. The first two steps in the Ostwald process for the production of nitric acid are the oxidations of NH3 to NO and of NO to NO2. The final step is a disproportionation, as the oxidation numbers show ... 

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.)... 

TABLE 2.6 Names of Oxoacids and Oxoanions That Contain Chlorine... 

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. 

SOME COMMON NITROGEN ELECTROPHILES OXIDES, OXOACIDS, AND OXOANIONS... 

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