Acid oxides: chemical properties, preparation, use
All chemical compounds that exist in nature are divided into organic and inorganic. Among the latter there are the following classes: oxides, hydroxides, salts. Hydroxides are divided into bases, acids and amphoteric. Among the oxides, acidic, basic and amphoteric can also be distinguished. The substances of the latter group can exhibit both acidic and basic properties.
Chemical Properties of Acid Oxides
Such substances have peculiar chemical properties. Acid oxides are able to enter into chemical reactions only with basic hydroxides and oxides. This group of chemical compounds includes substances such as carbon dioxide, sulfur dioxide and trioxide, chromium trioxide, manganese heptoxide, phosphorus pentoxide, chlorine trioxide and chlorine pentoxide, tetra- and nitrogen pentoxide, silicon dioxide.Such substances are also called anhydrides.The acidic properties of oxides are manifested primarily during their reactions with water. This forms a certain oxygen-containing acid. For example, if you take sulfur trioxide and water in equal quantities, we get sulfate (sulfuric) acid. Phosphoric acid can be synthesized in the same way by adding water to the phosphorus oxide. Reaction equation: Р2О5 + 3Н2О = 2Н3РО4. In the same way, it is possible to obtain such acids as nitrate, silicic, etc. Also, acid oxides enter into chemical interaction with basic or amphoteric hydroxides. During such reactions, salt and water are formed. For example, if you take sulfur trioxide and add calcium hydroxide to it, you get calcium sulfate and water. If you add zinc hydroxide, we get zinc sulfate and water. Another group of substances with which these chemical compounds interact - basic and amphoteric oxides. When the reactions with them is formed only salt, without water. For example, adding amphoteric alumina to sulfur trioxide, we obtain aluminum sulphate. And if you mix silicon oxide with basic calcium oxide, we get calcium silicate.In addition, acid oxides react with basic and normal salts. When reacting with the latter, acid salts form. For example, if you add calcium carbonate and water to carbon dioxide, you can get calcium bicarbonate. Reaction equation: CO2+ CaCO3+ N2O = Sa (NSO3)2. When acidic oxides react with base salts, normal salts are formed.
Substances of this group do not interact with acids and other acidic oxides. Exactly the same chemical properties are capable of manifesting amphoteric oxides, except that they also interact with acid oxides and hydroxides, that is, they combine both acidic and basic properties.
Physical properties and use of acidic oxides
There are quite a lot of acid oxides of various physical properties, therefore it is possible to use them in the most different spheres of industry.
Most often this compound is used in the chemical industry. It is an intermediate product formed in the process of obtaining sulfate acid. This process consists in the fact that iron pyrite is burned, while obtaining sulfur dioxide, then the latter is subjected to a chemical reaction with oxygen, due to which trioxide is formed.Further, from trioxide by adding water to it synthesize sulfuric acid. Under normal conditions, this substance is a colorless liquid with an unpleasant odor. At temperatures below sixteen degrees Celsius, the sulfur trioxide hardens to form crystals.
Acid oxides also include phosphorus pentoxide in their list. It is a white snow-like substance. It is used as a dehydrating agent due to the fact that it very actively interacts with water, thus forming phosphoric acid (it is also used in the chemical industry for its extraction).
It is the most abundant acid oxide in nature. The content of this gas in the composition of the Earth’s atmosphere is about one percent. Under normal conditions, this substance is a gas that has neither color nor odor. Carbon dioxide is widely used in the food industry: for the production of carbonated beverages, as a baking powder, as a preservative (under the designation E290). Liquefied carbon dioxide is used for the manufacture of fire extinguishers.Also, this substance plays a huge role in nature - for the commission of photosynthesis, as a result of which oxygen is vital for animals. Plants need carbon dioxide. This substance is released during combustion of all organic chemical compounds.
Under normal conditions has the form of colorless crystals. In nature, it can be found in the form of a variety of various minerals, such as quartz, crystal, chalcedony, jasper, topaz, amethyst, morion. This acid oxide is actively used in the manufacture of ceramics, glass, abrasive materials, concrete products, fiber-optic cables. Also, this substance is used in radio engineering. In the food industry, it is used as an additive, encrypted under the name E551. Here it is used to preserve the original shape and consistency of the product. This food additive can be found, for example, in instant coffee. In addition, silicon dioxide is used in the manufacture of toothpastes.
This substance is a brown-green mass. It is used mainly for the synthesis of manganese acid by adding water to the oxide.
It is a solid, colorless substance, in the form of crystals. It is used in most cases in the chemical industry to produce nitric acid or other nitrogen oxides.
Chlorine trioxide and tetraoxide
The first is a gas of green-yellow color, the second - the same color liquid. They are used mainly in the chemical industry to obtain the corresponding chloride acids.
Acid oxide production
Substances of this group may be obtained due to the decomposition of acids under the influence of high temperatures. In this case, the desired substance is formed and water. Examples of reactions: H2WITH3= N2O + CO2; 2H3Ro4= 3H2O + P2ABOUT5. Manganese heptaoxide can be obtained by exposing potassium permanganate to a concentrated solution of sulphate acid. Owing to this reaction, the desired substance is formed, potassium sulfate and water. Carbon dioxide can be obtained due to the decomposition of carboxylic acid, the interaction of carbonates and bicarbonates with acids, the reactions of baking soda with citric acid.
Summarizing everything written above, we can say that acid oxides are widely used in the chemical industry.Only some of them are also used in food and other industries.
Acid oxides are a large group of inorganic chemical compounds that are of great importance and can be used to produce a wide variety of oxygen-containing acids. Also in this group are two important substances: carbon dioxide and silicon dioxide, the first of which plays a huge role in nature, and the second is represented in the form of many minerals, often used in the manufacture of jewelry.