What is the difference between displacement and double displacement reactions? Write equations for these reactions.

Explanation

The chemical reactions in which one element takes the place of another element is called displacement reaction.
For example : Zinc displaces copper from copper sulphate solution:
`Zn_((s))+CuSO_(4(aq))toZnSO_(4(aq))+Cu_((s))`
Double displacement reactions are those in which two compounds react to form two other compounds by mutual exchange of atoms or group of atoms. For example, in the reaction between barium chloride and sulphuric acid, barium chloride exchanges its `Cl^(-)` ions with `SO_(4)^(2-)` ions of `H_(2)SO_(4)`.
`BaCl_(2(aq))+H_(2)SO_(4(aq))toBaSO_(4(s))+2HCl_((aq))`