Acid oxides: a brief description of the group

Acidic oxides are a fairly large group of complex substances that react with alkalis. With this, salt formation occurs. But with acids they do not interact.

Acidic oxides are formed mainly by non-metals. For example, sulfur, phosphorus and chlorine can be assigned to this group. In addition, substances with the same properties can be formed from so-called transition elements with a valence of five to seven.

Acidic oxides can react with water to form acids. Each inorganic acid has an appropriate oxide. For example, sulfur oxides form sulfate and sulphite acids, and phosphorus - ortho- and metaphosphate acid.

Acid oxides and methods for their preparation

There are several basic methods for obtaining oxides with acid properties.

The most common method is the oxidation of non-metal atoms by oxygen. For example, when phosphorus reacts with an oxygen , phosphorus oxide is produced. Of course, this method is not always possible.

Another fairly common reaction is the so-called firing of oxygen sulfides. In addition, oxides are also produced by the reaction of certain salts with acids.

Sometimes a slightly different technique is used in laboratories. During the reaction, the appropriate acid is taken away from the water - a dehydration process takes place. By the way, that's why acid oxides are known under another name - acid anhydrides.

Chemical properties of acidic oxides

As already mentioned, anhydrides can interact with basic oxides or alkalis. As a result of such a reaction, the salt of the corresponding acid is formed, and in the reaction with the base, water is also formed. It is this process that characterizes the basic acid properties of oxides. In addition, anhydrides do not interact with acids.

Another property of these substances is the possibility of reaction with amphoteric bases and oxides. As a result of this process, salts are also formed.

In addition, some anhydrides react with water. As a result of this process, the formation of the corresponding acid is observed. It is in this way, in the laboratory, for example, sulfuric acid is produced.

The most common anhydrides: a brief description

The most common and known acidic oxide is carbon dioxide. This substance under normal conditions is a colorless gas without a smell, but with a weak sour taste.

By the way, at atmospheric pressure, carbon dioxide can exist either in gaseous or solid state (dry ice). In order to convert the carbonic anhydride into a liquid, it is necessary to increase the pressure. It is this property that is used to store matter.

Carbon dioxide belongs to the group of greenhouse gases, because it actively absorbs the infrared rays emitted by the earth , keeping heat in the atmosphere. Nevertheless, this substance is very important for the life of organisms. Carbon dioxide is contained in the atmosphere of our planet. In addition, it is used by plants in the processes of photosynthesis.

Sulfur anhydride, or sulfur trioxide, is another representative of this group of substances. Under normal conditions, it is a colorless, highly volatile liquid with an unpleasant, odorless odor. This oxide is very important in the chemical industry, since it produces the bulk of sulfuric acid.

Silicon oxide is another fairly well-known substance, which in the normal state is a crystal. By the way, sand consists precisely of this compound. Silicon oxide can be melted and solidified when heated. This is its property used in the production of glass. In addition, the substance practically does not conduct electric current, therefore it is used as a dielectric.