Oxoacids hydrogen names

When one or more hydron(s) are attached to an anion at (an) unknown position(s), or at (a) position(s) which one cannot or does not wish to specify, a hydrogen name (see Section IR-8.4) may be used. Such names may also be used for simpler compounds, such as partially dehydronated oxoacids. Certain of these names have accepted abbreviated forms, such as hydrogencarbonate, dihydrogenphosphate, etc. All such accepted abbreviated names are given in Section IR-8.5. 

The chapter on Oxoacids and Derived Anions (Red Book I, Chapter 1-9) has also been extensively modified. Now called Inorganic Acids and Derivatives (Chapter IR-8), it includes the slightly revised concept of hydrogen names in Section IR-8.4 (and some traditional ous and ic names have been reinstated for consistency and because they are required for organic nomenclature purposes, i.e. in the new Blue Book). 

Although a systematic method exists for naming oxoacids, many such laboratory reagents are well recognized by their common names (e.g. sulfuric acid, nitric acid, nitrous acid). A problem with many common names is that they often hide structural information and, most importantly, do not indicate the number of ionizable hydrogen atoms. Where large families of acids exist, e.g. the sulfur oxoacids, systematic names are usually more helpful than traditional ones. 

Other minor systems are also in use. Some are traditional, and some are very restricted in their application. These include acid nomenclature (inorganic, for oxoacids and derivatives), replacement nomenclature (mainly organic, to denote replacement of skeletal atoms in a parent rather than replacement of hydrogen atoms — oxa-aza replacement is one variant), functional class nomenclature (this is again principally organic and involves the use of type names such as alcohol, acid and ether) and subtractive nomenclatures (such as organic-deoxy and inorganic-debor). These will all be referred to briefly as appropriate. 

In addition to the oxoacids, there are a small number of other acids, such as HC1, that do not contain oxygen. Although the pure, gaseous compound HC1 is named hydrogen chloride according to the rules for binary compounds, the aqueous solution is named hydrochloric acid, HCl(a ). This example is typical of non-oxygen-containing acids The prefix hydro- and the suffix -ic acid are used for the aqueous solution in such cases. 

There are two main kinds of acids binary acids and oxoacids. A binary acid is composed of two elements hydrogen and a non-metal. Two examples of binary acids are hydrofluoric acid and hydrochloric acid. All binary acids have the general formula HX(aq). The H represents one or more hydrogen atoms. The X represents the non-metal. As you can see in Table 10.6, the names of binary acids are made up of the following parts ... 

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. 

Constructing a substitutive name generally involves the replacement of hydrogen atoms in a parent structure with other atoms or atom groups. Related operations, often considered to be part of substitutive nomenclature, are skeletal replacement (Section IR-6.2.4.1) and functional replacement in oxoacid parents (Section IR-8.6). Note that some operations in parent hydride-based nomenclature are not substitutive operations (e.g. formation of cations and anions by addition of H+ and H, respectively, cf. Sections IR-6.4.1 and IR-6.4.5). Names formed by the modifications of parent hydride names described in those sections are still considered part of substitutive nomenclature. 

Table IR-8.1 also includes anions derived from the neutral oxoacids by successive dehydronation. Many of these anions also have common names that are still acceptable, in some cases in spite of the fact that they are based on nomenclature principles that are now otherwise abandoned (e.g. nitrate/nitrite and perchlorate/chlorate/chlorite/hypochlorite). For names involving the prefix hydrogen , see Sections IR-8.4 and IR-8.5.

A ternary compound consists of three elements. Ternary acids (oxoacids) are compounds of hydrogen, oxygen, and (usually) a nonmetal. Nonmetals that exhibit more than one oxidation state form more than one ternary acid. These ternary acids differ in the number of oxygen atoms they contain. The suffixes -ous and -ic following the stem name of the central element indicate lower and higher oxidation states, respectively. One common ternary acid of each nonmetal is (somewhat arbitrarily) designated as the -ic acid. That is, it is named by putting the element stem before the -ic suffix. The common ternary -ic acids are shown in Table 4-16. It is important to learn the names and formulas of these acids, because the names of all other ternary acids and salts are derived from them. There are no common -ic ternary acids for the omitted nonmetals. 

Acid Names from Anion Names Acids are an important group of hydrogen-containing compounds that have been used in chemical reactions for centuries. In the laboratory, acids are typically used in water solution. When naming them and writing their formulas, we consider them as anions connected to the number of hydrogen ions (H" ) needed for charge neutrality. The two common types of acids are binary acids and oxoacids ... 

For other than very common oxoacids, lUPAC prefer to name acids as compounds of H, e.g. hydrogen chloride. For common oxoacids, however, they recommend the traditional name, or a more systematic... 

Oxoacids are acids that contain hydrogen, oxygen, and another element (the central element). The formulas of oxoacids are usually written with the H first, followed by the central element and then O. We use the following five common acids as our references in naming oxoacids ... 

Many oxoacids, such as H2SO4 and H3PO4, arepolyprotic— meaning that they have more than one ionizable hydrogen atom. In these cases, the names of anions in which one or more (but not all) of the hydrogen ions have been removed must indicate the number of H ions that remain, as shown for the anions derived from phosphoric acid ... 

The system also organizes the names of the corresponding anions (and therefore the salts) of the oxoacids. The anion is obtained by removing all the hydrogen ions from the acid. For example, when both hydrogens are removed from carbonic acid, H2CO3, the result is the species COf . As stated in Table 11.3, -ic acids become -ate anions, and -ous acids become -ite anions. It follows that must be... 

The majority of acids are ternary compounds. They contain three different elements—hydrogen and two other nonmetals. If one of the nonmetals is oxygen, the acid is called an oxoacid. Think of oxoacids as combinations of hydrogen ions (H ) and oxoanions. The scheme for naming oxoacids is similar to that outlined for oxoanions, except that the ending -ous is used instead of -ite and -ic instead of -ate. Several oxoacids are listed in Table 3.6. Also listed are the names and formulas of compounds in which the hydrogen of the oxoacid has been replaced by a metal, such as sodium. These compounds are called salts we will say much more about them in later chapters, beginning in Chapter 5. Acids are molecular compounds, and salts are ionic compoimds. 

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