Definition of Salts
Ionic solids obtained after the neutralization action of acids and bases are called salts. In this process, water is also formed with salts.
Acid + Base → Salt + Water
Cation and negative ions are present in aqueous solutions of salts. A cation is called an alkaline element and a negative ion is an acidic element because the cation of salt is obtained from alkali and a negative ion from acid. The properties of an aqueous solution of salt are the properties of the ions present in it.
Types of salts
There are many types of salts found in nature. These can be divided into these six groups-
1. Normal salts
The salts obtained from the complete neutralization of acids and bases are called normal salts. Salts lack interchangeable hydrogen or hydroxyl ions. Common salts dissolve in aqueous solutions to form the same type of cation and anion. Aqueous solutions of these salts may be acidic or alkaline or neutral.
HCl + NaOH → NaCl + H2O
2. Acidic salts
Acidic salts are formed by partial displacement of substitutable hydrogen atoms of an acid, ie these salts are obtained by incomplete neutralization of acids. These salts are acidic in nature due to the hydrogen ion in their aqueous solution.
H2SO4 + NaOH → NaHSO4 + H2O
3. Basic Salts
These salts are formed by the action of partial neutralization of alkali by an acid. They contain one or more substitutable hydroxide ions. More than one anion is present in their aqueous solution, one of which is hydroxide and the other is an anion. The solution is basic because it contains hydroxide.
Ca(OH)2 + HCl → Ca(OH)Cl + H2O
4. Double Salts
The solution of two or more common salts mixed in proportion to their molecular weight is obtained by crystallizing double salt. Such as alum, mohr salt, etc. These salts are found only in solid-state and in solution, these salts get decomposed into positive ions and negative ions of their elemental salts. Therefore, their solution exhibits the properties of solutions of common salts. The crystals of some of these salts have a certain amount of water coupled state called crystallization water. Such as Dhawan Soda (Na2CO3·10H2O), Mohar Salt ((NH4)2Fe(SO4)2(H2O)6), Potash Alum (K2SO4 Al2 (SO4)3 .24H2O), etc.
5. Mixed salts
The salts in which more than one acidic or alkaline element are present are called mixed salts. Such as bleaching powder (CaOCl2), sodium-potassium sulfate (NaKO4S), microcosmic salts (Na(NH4)HPO4), etc. These types of salts are ionized in aqueous solutions to produce more than one positive or negative ion.
6. Hybrid salts
The salts formed in association with two common and neutral salts which exist in both solid and solution states are called hybrid salts. The properties of these and ingredient salts vary. In the electric field, the hybrid salt behaves as a unit. Hybrid salts are ionized in water to form hybrid ions. Such as potassium ferrocyanide (K4[Fe(CN)6]·3H2O), sodium argentocyanide (Na[Ag(CN)₂]) , silver ammonium chloride ([Ag(NH3)2]Cl), etc.
[Ag(NH3)2]Cl + Cl– ⇄ [Ag ( NH3 )2 ]+
Na[Ag(CN)₂] Na⁺ + Ag⁺ + 2CN⁻