Acid oxides are a fairly large group of complex substances that react with alkalis. With this, salt formation occurs. But they do not interact with acids.
Acid oxides are formed mainly by non-metals. For example, sulfur, phosphorus and chlorine can be attributed to this group. In addition, substances with the same properties can be formed from the so-called transition elements with a valency of five to seven.
Acid oxides can form acids when reacted with water. Each inorganic acid has a corresponding oxide. For example, sulfur oxides form sulfate and sulfite acids, and phosphorus - ortho and metaphosphate acid.
Acid oxides and methods for their preparation
There are several basic methods for producing oxides with acidic properties.
The most common way is to oxidize non-metal atoms with oxygen. For example, the interaction of phosphorus with oxygen produces phosphorus oxide. Of course, such a method is not always possible.
Another fairly common reaction is the so-called burning of oxygen sulfides. In addition, oxides are also obtained by the reaction of certain salts with acids.
Sometimes in laboratories a slightly different technique is used. During the reaction, water is taken from the corresponding acid - a dehydration process takes place. By the way, that is why acid oxides are also known under another name - acid anhydrides.
Chemical properties of acid oxides
As already mentioned, anhydrides can interact with basic oxides or alkalis. As a result of this reaction, a 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 acidic properties of oxides. In addition, anhydrides do not interact with acids.
Another property of these substances is the possibility of reaction with amorphous 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. In this way, for example, sulfuric acid is obtained under laboratory conditions.
The most common anhydrides: a brief description
The most common and well-known acid oxide is carbon dioxide. This substance under normal conditions is a colorless, odorless gas, but with a weak sour taste.
By the way, at atmospheric pressure, carbon dioxide can exist either in a gaseous state or in a solid state (dry ice). In order to turn carbon anhydride into a liquid, it is necessary to increase the pressure. It is this property that is used to store the substance.
Carbon dioxide belongs to the greenhouse group, because it actively absorbs infrared rays emitted by the earth , retaining heat in the atmosphere. However, 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 ordinary conditions, it is a colorless, very volatile liquid with an unpleasant, asphyxiating odor. This oxide is very important in the chemical industry, since the bulk of sulfuric acid is produced from it.
Silicon oxide is another fairly well-known substance, which in the normal state is a crystal. By the way, sand consists of this particular compound. Silicon oxide is able to melt and solidify when heated. This property is used in the manufacture of glass. In addition, the substance practically does not conduct electric current, so I use it as a dielectric.