For this reason, when a metal is part of a mechanism or a machine useful for humanity, the intention is to prevent corrosion by means of special oils. If too much rust forms, the metal becomes brittle and the metal part can break, rendering it unusable. On the other hand, oxides are naturally found in mineral deposits where metals are abundant.examples of basic oxides
The general reaction that metals follow to become oxides is:
Metal + Oxygen -> Basic Oxide
The stoichiometry of this reaction must consider that the oxygen in the air is diatomic: O 2 , and each of its atoms has a valence of –2. This is going to compensate with the valence electrons that the metal contains.examples of basic oxides
- For metal with valence +1 : two metal atoms combine to satisfy -2 oxygen, as in the case of sodium oxide Na 2 O .
- For metal with valence +2 : a metal atom participates to satisfy the –2 of oxygen, as in the case of calcium oxide CaO .
- For metal with valence +3 : by cross valences, two metal atoms are compensated with three oxygen atoms, as in the case of aluminum oxide Al 2 O 3 .
Oxides manifest themselves either as minerals of various metals, or as a result of the corrosion of nails, cans, bottle caps and other metallic objects that, due to the economy of the industry, do not carry protection against the oxidative action of the environment.
They are called basic oxides because, when combined with water molecules H 2 O, they produce hydroxides of metals, substances that act as bases or alkalis, as a result of the following chemical reaction:examples of basic oxides
Basic oxide + Water -> Metal hydroxide
CaO + H 2 O -> Ca (OH) 2
Calcium oxide + Water -> Calcium hydroxide
20 examples of basic oxides
- Titanium dioxide (TiO 2 ): it is one of the whitest materials that exist, which is why it is used in the production of plastics, paints and waterproofing.
- Cobalt II oxide (CoO): it has been used since ancient times to make ceramics, as a coloring substance.
- Cobalt III oxide (Co 2 O 3 )
- Chromium III oxide (Cr 2 O 3 ): due to its green color, it is often used as a coloring additive for different plastic items, such as glasses. Chrome green originates from it.
- Chromium II oxide (CrO)
- Chromium oxide IV (CrO 2 )
- Chromium oxide VI (CrO 3 )
- Copper oxide II (CuO): it is used in welding, as a pigment, as a semiconductor and even as a food supplement.
- Calcium oxide or quicklime (CaO): used in the food industry to add calcium to certain products, in the chemical industry to make glass, in the preparation of corn for the process of creating nixtamal in the manufacture of tortillas.
- Zinc oxide (ZnO): it is a whitish powder substance that is frequently used in the manufacture of talc, accompanying the other components. It is also used in the manufacture of pharmaceuticals, cosmetics and in some deodorants.
- Magnesium oxide (MgO): has several uses; Among them, as a desiccant in medicine bottles, as an ingredient in fertilizers, hydrated combines with aluminum hydroxide to form milk of magnesia, and is added to cement.
- Tin oxide IV (SnO 2 ): used in the chemical industry for the synthesis of some acids. It is also a coloring.
- Tin II oxide (SnO): used as a catalyst, as a glass pigment, and as a reducing agent.
- Iron III oxide (Fe 2 O 3 ): due to its reddish color, it is used as a colorant to create pigments. Also, thanks to the lack of electrical conductivity, it has been used as an electrical insulator in different applications.
- Iron oxide II (FeO): has a characteristic black color that is used in pigments. It is added in the preparation of medicines and food; also in the cosmetic industry.
- Manganese III oxide (Mn 2 O 3 )
- Manganese Oxide IV (MnO 2 ): It has a particular brown color that has been used in oil painting since the Enlightenment.
- Manganese oxide VII (Mn 2 O 7 )
- Mercury oxide I (Hg 2 O)
- Mercury oxide II (HgO): used in the chemical industry to obtain elemental mercury.
30 examples according to valence
10 examples of metal oxides with valence +1
- Lithium oxide (Li 2 O)
- Sodium oxide (Na 2 O)
- Potassium oxide (K 2 O)
- Rubidium oxide (Rb 2 O)
- Cesium oxide (Cs 2 O)
- Mercury oxide I (Hg 2 O)
- Copper oxide I (Cu 2 O)
- Silver oxide (Ag 2 O)
- Chromium oxide I (Cr 2 O)
- Francium oxide (Fr 2 O)
10 examples of metal oxides with valence +2
- Magnesium oxide (MgO)
- Calcium oxide (CaO)
- Strontium oxide (SrO)
- Barium oxide (BaO)
- Iron oxide II (FeO)
- Zinc oxide (ZnO)
- Mercury oxide II (HgO)
- Cadmium oxide (CdO)
- Nickel oxide II (NiO)
- Platinum oxide II (PtO)
10 examples of metal oxides with valence +3 examples of basic oxides
- Aluminum oxide (Al 2 O 3 )
- Iron oxide III (Fe 2 O 3 )
- Copper oxide III (Cu 2 O 3 )
- Titanium oxide III (Ti 2 O 3 )
- Molybdenum oxide III (Mo 2 O 3 )
- Chromium III oxide (Cr 2 O 3 )
- Manganese III oxide (Mg 2 O 3 )
- Vanadium oxide III (V 2 O 3 )
- Scandium oxide (Sc 2 O 3 )
- Gold oxide III (Au 2 O 3 )