The reaction in which the place of the ion of a less reactive element in a compound is taken by another more reactive element by formation of its own ions, is called displacement reaction.
Example::
on adding zinc dust to blue coloured copper sulphate solution, a colourless solution of zinc sulphate is formed and heat is generated .
CuSO4(aq) + Zn (s) ZnSO4(aq) + Cu(s)
