Displacement reaction between zinc and copper. In this demonstration, zinc metal granules (5.00 g) are added to a solution of copper sulphate (2.00 M). A rapid metal displacement reaction occurs, and the shiny zinc granules darken rapidly as the copper deposits on them, and they have developed a pink coppery sheen by the end of the clip. Zinc is a more reactive metal than copper, and will therefore displace copper ions from solution according to the equation: Zn + CuSO4 Cu + ZnSO4.