Oxyacids Oxygen

Notice that this series differs from the oxyacids of chlorine, shown in Figure 19-6. In the chlorine oxyacids, oxygen atoms add successively and the first ionization constants become larger. In the phosphorus oxyacids, hydrogen atoms are successively replaced by O—H groups but the first ionization constants change very little. 

Nitrous and nitric acids are produced in the aqueous phase after NO2 and/or N2O3 are absorbed into solution and sulfur oxyacids, such as sulfite/bisulfite or pyrosulfite, are formed if SO2 dissolves in the solution. Interaction among oxides of nitrogen, nitrogen oxyacids, sulfur oxyacids, oxygen, and trace metal ions such as Fe(III) or Mn(II) can take place in a flue gas wet scrubber. Identifying all reactions involved in this complex system is impossible. However, important reactions must be identified and characterized in order to improve the performance of a scrubber. 

HF b.p. 19°C HCl b.p. -85°C). Unlike the other halogens, fluorine does not form higher oxides or oxyacids oxygen difluoride in fact reacts with water to give hydrogen fluoride. 

Phosphorus(lII) oxide, P4O6, phosphorus trioxide, m.p. 24°C, b.p. 174 C. A waxy material (burn P in deficiency of O2)- It burns in excess O2 to P2OJ, reacts with, e.g. CI2 to POCI3 and dissolves in water to give phosphorus(TII) oxyacids. The structure is similar to that of P40,o but without the terminal oxygens. 

Upon storage, the amount of ted phosphoms in soHd white or Hquid phosphoms may increase if the material is exposed to light or contains contaminants such as iodine, sulfur, selenium, or sodium that catalyze the conversion from white to ted. Also, because white phosphoms is generally stored under water, some surface oxidation to form viscous white or colored polymeric oxyacids also occurs, especially if the oxygen content of the water can be replenished by exposure to air. 

Sulphur molecules are Sg and it can exist in several forms. Its compounds are more acidic than those of oxygen and it may assume covalency up to six. It forms a series of oxides and oxyacids of diverse chemistry. Combustion yields mainly SO2, a cause of atmospheric pollution from sulphur-bearing fossil fuels. 

Oxyacids of sulphur and their anhydrides, mechanisms and reactivity in reactions of organic, 17, 65 Oxygen isotope exchange reactions of organic compounds, 3, 123... 

Let s work two examples illustrating the steps necessary to produce a good Lewis structure. We will take HN02 and XeF4 for these examples. The first molecule is nitrous acid. It is an example of an oxyacid. (Oxyacids are compounds containing hydrogen, oxygen, and one other element.) The other compound is xenon tetrafluoride. 

When drawing the Lewis structure of an oxyacid, you should place one acidic hydrogen atom on a separate oxygen atom. 

Among the oxyacids of sulfur the predilection to form an anhydride with a sulfur-sulfur bond, rather than one with an oxygen bridge between the two sulfurs, is not restricted to sulfenic acids. We will see in a subsequent section that sulfinic acids also do this. Their anhydrides have the sulfinyl sulfone structure. RS(0)S02R, rather than RS(0)0S(0)R. What is unique about the sulfenic acid-thiolsulfinate system, however, is the fact that the anhydride (thiolsulfinate) is strongly preferred thermodynamically over the acid at equilibrium. With any other type of common acid the reverse is true, of course. The uniqueness of the sulfenic acid-thiolsulfinate situation can perhaps best be appreciated by realizing that, if the same stability relationship between acid and anhydride were to exist for carboxylic acids, acetic acid would spontaneously dehydrate to acetic anhydride ... 

Ternary compounds are those containing three or more elements. If the first element in the formula is hydrogen, it is usually classified as an acid. If the formula contains oxygen in addition to the hydrogen, the compound is usually classified as an oxyacid. In general, if the first element in the formula is not hydrogen, the compound is classified as a salt. 

C—In general, the more oxygens present, the stronger the oxyacid. 

Among the oxygen group elements, while sulfur is oxidized to +6 oxidation state (in H2SO4), selenium and tellurium are oxidized to +4 oxyacids with the liberation of nitrogen dioxide ... 

Prepare a solution of iodic acid (see p. 109) and pour it into two test tubes. Pour a potassium iodide solution into one tube. What substance evolves Pour an iron(II) sulphate solution into the other tube. What do you observe Write the equations of the reactions. What properties of iodic acid do the above experiments indicate Write the formulas of the iodine oxyacids. What oxygen compounds of iodine are known How are they prepared ... 

More important for inorganic oxyacids is the number of oxygen atoms surrounding the central atom. Thus in the series of chlorine oxyacids. acid strength increases in the order HOCI < HOClO < H0C102 <- HOClOj. The trends in acidity of oxyacids, and even reasonably accurate predictions of their pKu values, can be obtained from 19... 

OXYACID. An acid that contains oxygen, such as chloric acid (HCIO3). 

Thio acids have already been defined (Chap. 18) as acids related to their parent oxyacids by replacement of one or more oxygen atoms by sulfur. Most thio acids themselves are unstable, but their salts are stable and some (particularly the thiosulfates and thiocyanates) are quite familiar. Organic derivatives of monothiophosphoric acid, (HO)3PS, have recently found application as insecticides. 

An oxoacid is an acid formed from a polyatomic ion that contains oxygen, hydrogen, and another element. (Oxoacids are called oxyacids in some chemistry textbooks). In Chapter 3, you learned the names of common polyatomic ions and their valences (oxidation numbers). The names of oxoacids are similar to the names of their polyatomic oxoanions. Only the suffix is different. Study the three rules and examples for naming oxoacids below. Then try the Practice Problems that follow. 

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