Displacement in solutions

More reactive metals displace less reactive metals from their compounds. For example, magnesium is more reactive than copper. It displaces copper from copper(II) sulfate solution.

magnesium + copper(II) sulfate → magnesium sulfate + copper

Mg(s) + CuSO4(aq) → MgSO4(aq) + Cu(s)

In this displacement reaction:

  • the copper coats the magnesium
  • the solution’s blue colour fades as blue copper(II) sulfate is replaced by colourless magnesium sulfate solution.
Displacement reaction