When a piece of zinc is added to copper sulphate solution, a displacement reaction occurs. Zinc, being more reactive than copper, displaces it from copper sulphate solution and forms a colourless solution of zinc sulphate. The balanced chemical equation for the reaction is:
Zn(s) + CuSO4(aq) → ZnSO4(aq) + Cu(s)
The reaction is a redox reaction, called the displacement reaction of metal because zinc is more reactive than copper according to the reactivity series. As the reaction proceeds, the solution changes from blue to colorless, and a reddish-brown solid forms on the surface of the zinc metal.
