1. Acidic salt – The salt formed by partial neutralization of a diprotic or a polyprotic acid is known as an acidic salt. These salts have ionizable H+ ion along with another cation. Mostly the ionizable H+ is a part of the anion. Some acid salts are used in baking.
For eg:- NaHSO4, KH2PO4 etc.
H2SO4 + NaOH →→ NaHSO4 + H2O
2. Basic or Alkali Salt – The salt formed by the partial neutralization of a strong base by a weak acid is known as a basic salt. They hydrolyze to form a basic solution. It is because when hydrolysis of basic salt takes place, the conjugate base of the weak acid is formed in the solution.
For eg:- White lead (2PbCO3·Pb(OH)2).
3. Double salt – The salts that contain more than one cation or anion are known as double salt. They are obtained by the combination of two different salts crystallized in the same ionic lattice.
For eg:- Potassium sodium tartrate (KNaC4H4O6.4H2O) also known as Rochelle salt.
4. Mixed Salts – The salt that consists of a fixed proportion of two salts, often sharing either a common cation or common anion is known as mixed salt.
For e.g. :- CaOCl2