Question

when is a chemical reaction considered a double displace ment reaction?explain giving example state a difference between displacement and double displacement reaction....

Answer 1

A double displacement reaction occurs when there is an exchange of ions between the reactants  (compounds ).

BaCl2 + H2SO4 ----> BaSO4 + 2HCl

In displacement reaction
According to reactivity series, the more reactive element DISPLACES the less reactive element in a compound.

Fe + CuSO4 ---> FeSO4 + Cu

Whereas in double displacement reaction, there is an EXCHANGE OF IONS, it's like BOTH THE ELEMENTS displace each other. In simple terms, exchange of ions.

Hope that helps!

Answer 2

NaCl + BaSo4 ----> BaCl + NaSo4.
In this the ions are been displaced