Salts - substances belonging to the class of inorganic compounds, which consist of the anion (acid residue) and cation (metal atom).In most cases, this crystalline substance of different colors and with different water solubility.The simplest representative of this class of compounds - common salt (NaCl).
salts are divided into acidic, basic and normal.
normal (average), in the case when all of the acid hydrogens are replaced by metal atoms, or when all of the hydroxyl groups are replaced by acid basis acid residues (e.g., MgSO4, Mg (CH3COO) 2).When electrolytic dissociation they decompose into positively charged metal anions and negatively charged anions.
chemical properties of the salts of this group:
• decompose at high temperatures;
• undergo hydrolysis (reaction with water);
• enter into reaction with acids, bases and other salts.It should be remembered some of the features of these reactions:
- the reaction of the acid takes place only when the acid is stronger than the one from which
- reaction with a base extends when formed insoluble substance;
- saline solution reacts with the metal, if it is in the electrochemical voltage range to the left of the metal, which is part of the salt;
- salt compound in solution react with each other, if it forms an insoluble product exchange;
• Redox, which can be attributed to the properties of cation or anion.
acid salts obtained in cases where only a portion of the hydrogen atoms in the acid is replaced with metal atoms (e.g., NaHSO4, CaHPO4).When electrolytic dissociation, they form hydrogen and metal cations, anions of the acid residue, so the chemical properties of the salts of this group include the following attributes as salt and acid compounds:
• are subjected to thermal decomposition to form a secondary salt;
• react with alkali to form a normal salt.
Basic salt obtained in cases where only a portion of the hydroxyl groups replaced by bases acidic acid residues (e.g., Cu (OH) or Cl, Fe (OH) CO3).Such compounds are dissociated into metal cations and hydroxyl anions and an acidic residue.The chemical properties of the salts of this group include the characteristic features of the chemical substances and salt, and bases at the same time:
• characterized by thermal decomposition;
• interact with the acid.
There is the notion of complex and double salts.
Complex contain complex anion or cation.Chemical properties of the salts of this type include the reaction of destruction complex, accompanied by the formation of sparingly soluble compounds.In addition, they are capable of exchanging ligands between the inner and outer sphere.
Dual also have two different cation may react with alkalis (reduction reaction).
Methods of preparing salts
These substances can be obtained in the following ways:
• interaction of acids with metals, which are able to displace the hydrogen atoms;
• the reaction of bases and acids, hydroxyl groups when the basics are exchanged with acids acid residues;
• action of acids amphoteric and basic oxides, salts or metals;
• grounds for action on acid oxides;
• reaction between acidic and basic oxides;
• interaction among themselves or salts with metals (substitution reaction);
• The preparation of salts in the reactions of metals with non-metals;
• acid salt compounds are prepared by the reaction medium salts with an acid of the same name;
• basic substance salt is prepared by reacting the salt with a small amount of alkali.
Thus, salts may be prepared in many ways, since they are produced as a result of many chemical reactions between the inorganic substances and compounds.