Chemical properties of acids
Acids are complex compounds that include hydrogen atoms that have the ability to be replaced by metal atoms and an acid residue.
Acids are electrolytes. The chemical properties of acids are determined by their composition.
The acids are classified according to various characteristics:
1. By the number of hydrogen atoms.
2. By the presence of oxygen atoms.
3. The degree of dissociation.
According to the number of oxygen atoms (the chemical properties of acids depend on this), they are divided into oxygen-free (hydrogen sulphide, hydrochloric, etc.) and oxygen-containing (nitric, sulfuric, silicic, etc.)
The number of hydrogen atoms of acid are:
- monobasic, containing one hydrogen atom (hydrochloric, nitric);
- dibasic, containing two hydrogen atoms (sulfuric, hydrogen sulfide);
- tribasic, containing three hydrogen atoms (orthophosphoric).
According to the third sign, the acids are divided into weak electrolytes (phosphoric, coal, etc.) and strong electrolytes (hydrochloric, nitric, sulfuric).
Chemical properties of acids
The presence of hydrogen ions in acid solutions determines their acidic environment and sour taste. However, you can not try them on the tongue, as a chemical burn is possible.
Indicators litmus and methylorange under the influence of acids change their color.
Acid solutions react with basic oxides, resulting in the formation of salt and water.
The acids react with the metals to the left of the hydrogen element in the series of metal stresses. As a result, a metal salt and hydrogen are formed.
The acids react with the bases. As a result of the reaction, salt and water are formed. The interaction between acid and alkali (base) is called the neutralization reaction.
Acids react with solutions of salts, when the condition for the appearance and flow of the ion exchange reaction is fulfilled to the end, that is, a precipitate or gas is released.
The chemical properties of organic acids have their own characteristics.
Properties of phosphoric acid
Phosphoric acid and its aqueous solutions are muchWeaker than acids such as nitric and sulfuric. It is an acid in which there are three oxygen atoms. Electrolytic dissociation of phosphoric acid occurs stepwise. A typical acid is phosphoric acid, the chemical properties are determined by its composition.
In a solution of phosphoric acid in the mainthere are dihydrogen phosphate ions. Ions, which are formed in the second stage of dissociation, are much smaller, and phosphate ions, the result of the third stage of ionization, are almost absent. In the first stage, phosphoric acid is an acid of medium strength. Since there are three types of acid residues, the interaction of phosphoric acid with alkali produces the following salts: phosphates, hydrophosphates and dihydrogen phosphates.
Orthophosphoric acid can be distinguished from anotheracid on the interaction with silver nitrate, which results in the formation of a yellow precipitate. Other phosphoric acids, reacting with silver nitrate, form a white precipitate. Orthophosphoric acid, when heated, cleaves water and forms pyrophosphoric acid.
Chemical properties of hydrochloric acid
Hydrochloric acid is a strong monobasicacid with typical properties of acids. A colorless, slightly fuming liquid, a solution of hydrogen chloride in water. Salts of hydrochloric acid are called "chlorides".
Hydrochloric acid can be obtained as a result ofinteraction of solutions of common salt and sulfuric acid, and also dissolving hydrogen chloride in water. Hydrochloric acid reacts with bases, resulting in the formation of salts and water. When reacting with alkali, a neutralization reaction occurs. This can be checked by an indicator. Its color will change, confirming the neutrality of the solution.
The reaction of hydrochloric acid and silver nitrate leads to the formation of an insoluble silver chloride salt, which precipitates.
Hydrochloric acid reacts with the active metals. If zinc is placed in its solution, active formation and evolution of hydrogen will begin.
Hydrochloric acid, as a typical acid, reacts with bases, metals and salts.
