All About Oxide

An oxide is a chemical compound that contains at least one oxygen atom and one other element. Oxides are important in both industry and everyday life. In this article, we will discuss the different types of oxides, their properties, and some examples of applications.

Meaning of Oxides

An oxide is a chemical compound that contains at least one oxygen atom and one other element in its chemical formula. Oxide can contain more than one oxygen atom, as in the case of dioxygen (O₂), trioxygen (O₃), or tetraoxygen (O₄). 

Examples of Oxides

Dioxygen (O₂) is the most common oxide. It is a colourless, odourless gas that makes up 21% of the Earth’s atmosphere.

Carbon dioxide (CO₂) is another example of an oxide. It is a colourless, odourless gas that is produced by animals during respiration and by plants during photosynthesis.

Water (H₂O) is another oxide. It is a colourless, odourless liquid that makes up 71% of the Earth’s surface.

Types of Oxides

There are two main types of oxides:

1. Acid Oxides
2. Base Oxides

Acid Oxides

Acid oxides are oxides that react with water to form an acid. For example, when carbon dioxide (CO₂) reacts with water, it forms carbonic acid (H₂CO₃). Similarly, when sulphur dioxide (SO₂) reacts with water, it forms sulphuric acid (H₂SO₃).

Base Oxides

Base oxides are oxides that react with water to form a base. For example, when magnesium oxide (MgO) reacts with water, it forms magnesium hydroxide (Mg(OH)₂), which is a base. Similarly, when aluminium oxide (Al₂O₃) reacts with water, it forms aluminium hydroxide (Al(OH)₃), which is also a base.

Uses of Oxides

Oxides have a variety of uses:

• Acid oxides are used in the production of acids, such as sulphuric acid (H₂SO₄) and nitric acid (HNO₃).
• Base oxides are used in the production of bases, such as sodium hydroxide (NaOH) and calcium oxide (CaO).
• Oxides can also be used as catalysts, such as in the production of ammonia (NH₃) from nitrogen dioxide (NO₂).
• Some oxides, such as iron oxide (Fe₃O₄), are used in the production of pigments and dyes.
• Other oxides, such as silicon dioxide (SiO₂), are used in the production of glass and ceramics.

Structure of Oxides

The oxides of the elements can be divided into three main groups according to their structure; molecular, covalent, or ionic. The great majority of simple binary compounds are molecular, e.g. CO, SO₂, and H₂O₂. A few exceptions occur, such as NO and ClO₂. The structure of these oxides is determined by the relative sizes of the atoms and their electronegativities. The size of the oxide molecule is also important in determining its properties.

Molecular Oxides

Molecular oxides generally have low melting and boiling points and are poor conductors of electricity. They are usually gases or volatile liquids at room temperature. The oxides of the heavier elements, such as sulphur and phosphorus, are solids at room temperature but have low melting points.

Covalent Oxides

Covalent oxides generally have higher melting and boiling points than molecular oxides. They are poor conductors of electricity in the solid-state, but good conductors in the molten or dissolved state. The majority of the oxides of the nonmetals are covalent.

Ionic Oxides

Ionic oxides have high melting and boiling points and are good conductors of electricity in both the solid and molten states. They are made up of giant lattices of ions held together by electrostatic forces. The vast majority of metal oxides are ionic.

In general, the more covalent character an oxide has, the more acidic it will be. The more ionic character an oxide has, the more basic it will be. Some oxides can exhibit both acidic and basic properties, depending on the circumstances. For example, water vapour (H₂O) is a molecular oxide and is neutral. However, when water vapour dissolves in water (H₂O), it forms an oxide of hydrogen (H₃O⁺) which is acidic. Similarly, when solid magnesium oxide (MgO) is added to water, it dissociates into Mg⁺² and OH⁻ ions, which makes the solution basic.

Valency Of Oxides

The valency of oxide is the number of oxygen atoms that can be combined with one atom of the element to form a compound. Most metals have a valency of two or more and the vast majority of metal oxides are binary compounds, i.e. they contain two atoms of different elements. The valency of the oxide can be determined by the formula:

Valency of Oxide = Number of atoms of oxygen in one molecule of the oxide

For example, the valency of magnesium oxide (MgO) is two because there are two oxygen atoms in one molecule of MgO. The valency of aluminium oxide (Al₂O₃) is three because there are three oxygen atoms in one molecule of Al₂O₃.

Conclusion

Oxides are a type of chemical compound that contains oxygen in their molecular structure. In this blog post, we’ve explored the different types of oxides and their properties. We’ve also looked at some examples of how oxides are used in everyday life. Oxides are a very important class of materials with a wide range of applications. They are also very versatile and can be used in many ways. If you have any questions about oxides or want to learn more about them, please leave us a comment below. And don’t forget to check out our other posts on chemistry for students!