displacement reaction

Chemical reaction in which a less reactive element is replaced in a compound by a more reactive one.

For example, the addition of powdered zinc to a solution of copper(II) sulphate displaces copper metal, which can be detected by its characteristic colour:

Zn(s) + CuSO4(aq) → ZnSO4(aq) + Cu(s)

The copper is taken out of the solution and is deposited as a solid (s).

In the electrochemical series (a list of chemical elements arranged in descending order of the ease with which they can lose electrons to form cations (positive ions)), an element can be displaced from a compound by any element above it in the series.