Oxidation numbers of oxygen

Oxygen is ordinarily assigned an oxidation number of —2 in its compounds. (An exception arises in compounds containing the peroxide ion, 022-, where the oxidation number of oxygen is —1.)... 

The oxidation number of oxygen is —2 in most of its compounds. Exceptions are its compounds with fluorine (in which case, the previous statement takes precedence) and its occurrence as peroxides (022-), superoxides (02 ), and ozonides (03 ). 

SOLUTION The process is oxidation if the oxidation number of sulfur increases, reduction if it decreases. We need to assign the oxidation numbers of sulfur in S02 and S042, then compare them. To assign an oxidation number to sulfur we represent that number by x and solve for x, by using the rules in Toolbox K.l. The oxidation number of oxygen is —2 in both compounds. 

The oxidation number of oxygen in its compounds is -2 except in peroxides (where it is -1), superoxides (where it is - ), or in OF2 and 02F2 (where it is positive). The peroxides and superoxides generally occur only with other elements in their maximum oxidation states. You will be able to recognize peroxides or superoxides by the presence of pairs of oxygen atoms and by the fact that if the compounds were normal oxides, the other element present would have too high an oxidation number (Sec. 13.3). 

The more electronegative element will take the negative oxidation state, (a) The maximum oxidation state of sulfur is +6 the most common negative oxidation number of oxygen is -2. Therefore, it takes three oxygen atoms to balance one sulfur atom, and the formula is SO v (b) The maximum oxidation state of carbon is +4 the only oxidation number of fluorine in its compounds is - 1. Therefore, it takes four fluorine atoms to balance one carbon atom, and the formula is CF4,... 

The oxidation number of oxygen is -2 in compounds, except for peroxides, in which it is -1. 

The oxidation number of oxygen in its compounds is usually -2, but there are exceptions. These include peroxides, such as H2O2, and the compound OF2. The oxidation nnmber of 0 in Li20 or in KNO3 is -2. 

As stated in rule 4, oxygen does not always have its usual oxidation number of -2. Determine the oxidation number of oxygen in each of the following. 

The oxidation number of nitrogen increases from -3 to +4, an increase of 7. The oxidation number of oxygen decreases from 0 to -2, a decrease of 2. The least common multiple of 7 and 2 is 14. In this case, two nitrogen atoms must react for every seven oxygen atoms so that the total increase and decrease in oxidation numbers both equal 14. 

The oxidation number of oxygen is almost always —2. The only common exceptions are peroxides, in which two oxygen atoms are connected and each has an oxidation number of —1. Two examples are hydrogen peroxide (H—O—O—H) and its anion (H—O—O ). The oxidation number of oxygen in gaseous 02 is, of course, 0. 

What is the oxidation number of oxygen in each of the following compounds ... 

In compounds, the oxidation number of oxygen is generally 2 except in F20 wherein oxidation... 

In peroxides, the oxidation number of oxygen IS -1, and in superoxides, it is -5. The only common superoxides are those of hydrogen and the alkali metals from potassium through francium. Peroxides occur with hydrogen, sodium, barium, and chromium, and in these compounds, each of these elements exists in its highest oxidation state. 

The oxidation number of oxygen in most of its compounds is -2 (rule 7). The oxidation numbers of the two oxygen atoms plus that of the nitrogen atom must total 1-, the charge on the ion ... 

The oxidation numbers of oxygen and iron are 2- and 2+, respectively, in FeO. Similarly, the oxidation number of oxygen is 2-. Then, the oxidation number of Fe in Fe203 is ... 

There is a single covalent bond between the two oxygen atoms. The oxidation number of oxygen in the peroxide ion and in peroxides is - 1. These substances represent an intermediate oxidation state between free oxygen (oxygen with oxidation number 0 in Oo) and oxides... 

The oxidation number of oxygen in compounds is always —2, except in peroxides, such as hydrogen peroxide (H2O2), where it is —1. When it is bonded to fluorine, the only element more electronegative than oxygen, the oxidation number of oxygen is +2. 

Oxygen is assigned oxidation number —2 in nearly all compounds. However, there are two exceptions In compounds with flnorine, convention 3 takes precedence, and in compounds that contain 0—0 bonds, conventions 2 and 4 take precedence. Thus, the oxidation number for oxygen in OF2 is +2 in peroxides (such as H2O2 and Na202), it is 1. In superoxides (such as KO2), the oxidation number of oxygen is —5. 

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