Oxidation of nonmetals

Valence and oxidation state are directly related to the valence-shell electron configuration of a group. Binary hydrides are classified as saline, metallic, or molecular. Oxides of metals tend to be ionic and to form basic solutions in water. Oxides of nonmetals are molecular and many are the anhydrides of acids. 

The general nature of this reaction indicates that oxides of nonmetals react with water to produce acidic solutions. Such oxides are sometimes referred to as acidic anhydrides. 

As we have seen earlier in the case of proton transfer reactions such as occurs between HCl(g) and NH3(g), water is not necessary for the acid-base reaction to take place. This is also true of the reactions between the acidic oxides of nonmetals and the basic oxides of metals. In many cases, they react directly as illustrated in the following equations ... 

Although they are oxides of nonmetals, CO and N20 do not give acidic solutions when added to water. However, they are formally the anhydrides of formic and hyponitrous acid, respectively. 

Because the oxides of nonmetals are acid anhydrides, CO is formally the anhydride of formic acid. 

Many oxides of nonmetals are gaseous molecular compounds, such as C02, NO, and S03. Most can act as Lewis acids, because the electronegative oxygen atoms withdraw electrons from the central atom, enabling it to act as an electron-pair acceptor. For instance, carbon dioxide can react with the oxides of metals because the oxide ion in the metallic oxide is a strong Lewis base ... 

Many oxides of nonmetals form acidic solutions in water and hence are called acid anhydrides. The familiar laboratory acids HN03 and H2S04, for instance, are derived from acidic binary oxides. Even oxides that do not react with water can be regarded as the formal anhydrides of acids. A formal anhydride of an acid is the molecule obtained by striking out the elements of water (H, H, and O) from the molecular formula of the acid. Carbon monoxide, for instance, is the formal anhydride of formic acid, HCOOH, although CO does not react with cold water to form the acid. 

Additional examples of neutral Lewis acids are oxides of nonmetals, such as C02, S02, and S03. The reaction of S03 with water, for example, can be viewed as... 

Because the oxides of nonmetals are usually acidic, whereas those of metals are basic, reactions between the oxides themselves may take place to produce salts directly ... 

Oxygen Oxides of nonmetals can dissolve in water to form acids these oxides are called acidic oxides, e.g. C02. Some elements also form neutral oxides, e.g. hydrogen oxide, H20, or water. For superoxide see SOD. A gas that comprises 20 % of the air. It is essential to life. 

Some oxides of nonmetals can combine with water to produce acids. Carbon dioxide combines with water to form carbonic acid. 

Main-group binary oxides of nonmetals are acidic. Example SO3... 

Many oxides of nonmetals are gaseous molecular compounds. Most can act as Lewis acids. They form acidic solutions in water and are called acid anhydrides. 

Nearly all oxides of nonmetals react with water to give solutions of ternary acids. The Figure 6-9 Sulfur burns in oxygen oxides of boron and silicon, which are insoluble, are two exceptions. to form sulfur dioxide. 

Carbon dioxide is called an acid anhydride, that is, an acid without water. As noted in Section 6-8, part 2, many other oxides of nonmetals, such... 

This brief examination of oxides of the third-period elements shows that as the metallic character of the elements decreases from left to right across the period, their oxides change from basic to amphoteric to acidic. Metallic oxides are usually basic, and most oxides of nonmetals are acidic. The intermediate properties of the oxides (as... 

The formation of caverns occurs because carbon dioxide is an acid anhydride. An acid anhydride is an oxide that can combine with water to form an acid. Other oxides combine with water to form bases. For example, calcium oxide (CaO, lime) forms the base calcium hydroxide Ca(OH)2. In general, oxides of metallic elements form bases oxides of nonmetals form acids. 

The oxides of nonmetals tend to be acidic when dissolved in water. 

Ceric oxidation of nonmetals (including Belusov-Zhabotinsky oscillating reaction)... 

Before we consider the chemical processes that occur in the atmosphere, let s review some of the properties of the two major components, N2 and O2. Recall that the N2 molecule possesses a triple bond between the nitrogen atoms. (Section 8.3) This very strong bond (bond energy 941 kj/mol) is largely responsible for the very low reactivity of N2. The bond energy in O2 is only 495 kJ/mol, making O2 much more reactive than N2. For example, oxygen reacts with many substances to form oxides. The oxides of nonmetals, such as SO2, usually form acidic solutions when dissolved in water. The oxides of active metals, such as CaO, form basic solutions when dissolved in water. 

This brief examination of oxides of the third-period elements shows that as the metallic character of the elements decreases from left to right across the period, their oxides change from basic to amphoteric to acidic. Metallic oxides are usually basic, and most oxides of nonmetals are acidic. The intermediate properties of the oxides (as shown by the amphoteric oxides) are exhibited by elements whose positions are intermediate within the period. Note also that because the metallic character of the elements increases from top to bottom within a group of representative elements, we would expect oxides of elements with higher atomic numbers to be more basic than the lighter elements. This is indeed the case. 

Many oxides of nonmetals in the upper-right portion of the periodic table react with water to produce oxyacids. For example, sulfur dioxide, SO2, reacts with water to produce sulfurous acid. 

Certain oxides such as CO and NO are neutral that is, they do not react with water to produce acidic or basic solutions. In general, oxides of nonmetals are either addic or neutral. 

Oxides of metals generally are basic oxides of nonmetals generally are acidic. 

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