Question

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

Answer 1

In displacement reaction, more reactive element displaces the less reactive element from its compound. For example

$\mathrm{Zn}\left(s\right)+{\mathrm{CuSO}}_4\left(\mathrm{aq}\right)\to {\mathrm{ZnSO}}_4\left(\mathrm{aq}\right)+\mathrm{Cu}\left(s\right)$

But in double displacement reaction, mutual exchange of ions takes place. For example

$\mathrm{HCl}\left(\mathrm{aq}\right)+{\mathrm{AgNO}}_3\left(\mathrm{aq}\right)\to \mathrm{AgCl}\left(s\right)+{\mathrm{HNO}}_3\left(\mathrm{aq}\right)$