Oxoacid oxygen atoms

Phosphorus forms a large number of oxoacids, many of which cannot be isolated but do form stable salts. In general, ionisable hydrogen is bonded to the phosphorus through an oxygen atom hydrogen atoms attached directly to phosphorus are not ionisable. 

Now let s consider a family of oxoacids in which the number of oxygen atoms varies, as in the chlorine oxoacids HCIO, HCI02, HCIQ3, and HCIQ4 or in the... 

Phosphoric acid, sulfuric acid, and the hydrogen sulfate ion are members of a group of acids known as oxoacids. An oxoacid has a central atom bonded to a variable number of oxygen atoms and OH groups. Except for the three oxoacids shown in Table (sulfuric acid, nitric acid, and perchloric acid), all of the oxoacids described in this textbook are weak acids. Chapter 17 describes in detail the chemistry of strong and weak acids, including carboxylic acids and oxoacids. 

The relative strength of oxoacids increases with the number of oxygen atoms. 

Acceptable abbreviated names may be given to potyoxoacids formally derived by condensation (with evolution of water) of units of the same mononuclear oxoacid, provided that the central atom of the mononuclear oxoacid lias the highest oxidation state of the Periodic Croup to which it belongs, that is, VI for sulfur, etc. The names are formed by indicating with numerical prefixes the number of atoms of central dement present. It is not necessary to slate the number oF oxygen atoms. 

Names of monatomic anions end in -ide oxoanions are anions that contain oxygen. Oxoacids are molecular acids that contain oxygen. Within a series, the suffixes -ate and -ic acid indicate a greater number of oxygen atoms than the suffixes -ite and -ous acid. 

In nearly all common oxoacids, however, all the hydrogen atoms are attached to oxygen atoms. 

To name an acid, look at the formula and decide whether the compound is an oxoacid. If so, the name must reflect the number of oxygen atoms, according to Table 2.4. If the compound is not an oxoacid, it is named using the prefix hydro- and the suffix -ic acid. 

Oxoacids, such as H2C03, HN03, H2S04, and HCIO, have the general formula H YO, , where Y is a nonmetallic atom, such as C, N, S, or Cl, and n and m are integers. The atom Y is always bonded to one or more hydroxyl (OH) groups and can be bonded, in addition, to one or more oxygen atoms ... 

For oxoacids that contain the same atom Y but different numbers of oxygen atoms, acid strength increases as the oxidation number of Y increases. The oxidation number of Y increases, in turn, as the number of oxygen atoms increases. This effect is illustrated by the oxoacids of chlorine ... 

The greater the number of yf I oxygen atoms, the higher the oxidation state of the halogen and the stronger the oxoacid. 

For oxoacids that vary only by the number of oxygens (i.e., HAO, HA02, HA03), which of the following occurs as the number of oxygen atoms increases ... 

The correct answer is (B). For oxoacids, as the number of oxygen atoms attached to atom A in the molecule increases, it becomes easier to remove the proton. This will increase the acidity of the oxoacid. 

The correct answer is (C). The general trend for oxoacids is that the greater the number of oxygen atoms, the greater the strength of the acid. 

The prefixes and suffixes used in Chapter 6 can also be interpreted in terms of oxidation numbers, rather than numbers of oxygen atoms. For example, the ending -ous corresponds to the oxoacid in which the central atom has the lower oxidation state in each case, and the ending -ic corresponds to the higher oxidation state. For example phosphorous acid has phosphorus in the +3 oxidation state phosphoric acid has phosphorus in the + 5 oxidation state. Phosphorus in hypophosphorous acid has an oxidation number +1. 

Phosphoms is the name of the element, and phosphorous is the name of the oxoacid with one fewer oxygen atom than phosphoric acid. 

Fluorine does not form an oxoacid the element is more electronegative than oxygen. In the chlorine, bromine and iodine compounds the halogen atom is positive in relation to the oxygen atoms, as indicated by the <5 s ... 

The strength of oxoacids with a given central element X increases with the number of lone oxygen atoms attached to the central atom. If the formula of these acids is written as XO (OH) the corresponding acid strengths fall into distinct classes according to the value of n, the number of lone oxygen atoms (see... 

Table 15.3). Each increase of 1 in w increases the acid ionization constant by a factor of about 10. Another way to describe this effect is to focus on the stability of the conjugate base, XO +i(OH) i, of the oxoacid. The greater the number of lone oxygen atoms attached to the central atom, the more easily the net negative charge can be spread out over the ion, and therefore the more stable the base. This leads to a larger K. ...

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