A salt is a compound formed when the hydrogen ion of an acid is partially or totally replaced by a metal or ammonium ion. There are 2 types of salt:
Acidic salts: these salts are formed when the hydrogen ions of an acid is only partially replaced by a metal ion or the ammonium ion. Examples of acid salts are sodium bicarbonate (NaHCO3), sodium hydrosulfide (NaHS), sodium bisulfate (NaHSO4), monosodium phosphate (NaH2PO4) and disodium phosphate(Na2HPO4).
Example: Sodium bisulfate (NaHSO4)
Sodium bisulphate is formed by the partial neutralization of sulphuric acid by sodium hydroxide.
NaOH(aq) + H2SO4 (aq) → NaHSO4 + H2
Normal salts: these are salts formed when the hydrogen ions of an acid are completely replaced by a metal ion or ammonium ion.
2NaOH+ H2SO4 → Na2SO4 + 2H20, where all hydrogen ions are replaced
Salts may be either soluble or insoluble.
Insoluble salts may be prepared in the following ways:
Soluble salts can be prepared by the following reactions:
-acid and an alkali
-an acid and excess carbonate hydrogen carbonate
-an acid and an excess metal oxide
-an acid and an excess active metal