Summarizing Occurrence, Preparation, and Compounds of Oxygen

Key Concepts and Summary

Oxygen is one of the most reactive elements. This reactivity, coupled with its abundance, makes the chemistry of oxygen very rich and well understood.

Compounds of the representative metals with oxygen exist in three categories (1) oxides, (2) peroxides and superoxides, and (3) hydroxides. Heating the corresponding hydroxides, nitrates, or carbonates is the most common method for producing oxides. Heating the metal or metal oxide in oxygen may lead to the formation of peroxides and superoxides.

The soluble oxides dissolve in water to form solutions of hydroxides. Most metals oxides are base anhydrides and react with acids. The hydroxides of the representative metals react with acids in acid-base reactions to form salts and water. The hydroxides have many commercial uses.

All nonmetals except fluorine form multiple oxides. Nearly all of the nonmetal oxides are acid anhydrides. The acidity of oxyacids requires that the hydrogen atoms bond to the oxygen atoms in the molecule rather than to the other nonmetal atom. Generally, the strength of the oxyacid increases with the number of oxygen atoms bonded to the nonmetal atom and not to a hydrogen.

Glossary

base anhydride

metal oxide that behaves as a base towards acids

chlor-alkali process

electrolysis process for the synthesis of chlorine and sodium hydroxide

hydrogen sulfate

\({\text{HSO}}_{4}{}^{-}\) ion

hydrogen sulfite

\({\text{HSO}}_{3}{}^{-}\) ion

hydroxide

compound of a metal with the hydroxide ion OH⁻ or the group −OH

nitrate

\({\text{NO}}_{3}{}^{-}\) ion; salt of nitric acid

Ostwald process

industrial process used to convert ammonia into nitric acid

oxide

binary compound of oxygen with another element or group, typically containing O²⁻ ions or the group –O– or =O

ozone

allotrope of oxygen; O₃

peroxide

molecule containing two oxygen atoms bonded together or as the anion, \({\text{O}}_{2}{}^{2-}\)

photosynthesis

process whereby light energy promotes the reaction of water and carbon dioxide to form carbohydrates and oxygen; this allows photosynthetic organisms to store energy

sulfate

\({\text{SO}}_{4}{}^{2-}\) ion

sulfite

\({\text{SO}}_{3}{}^{2-}\) ion

superoxide

oxide containing the anion \({\text{O}}_{2}{}^{-}\)