• The reactivity of metals decreases going down the reactivity series.
• This means that a more reactive metal will?displace?a less reactive metal from its compounds
• Two examples are:
  • Reacting a metal with a metal oxide (by heating)
  • Reacting a metal with an aqueous solution of a metal compound

   

• For example it is possible to reduce copper(II) oxide by heating it with zinc.
• The reducing agent in the reaction is zinc:

Zn? ? +? ? ?CuO? ? →? ? ZnO? ? +? ? Cu

zinc + copper(II) oxide → zinc oxide + copper

Metal Oxide Displacement Table

Displacement reactions between metals & aqueous solutions of metal salts

• The reactivity between two metals can be compared using?displacement reactions?in salt solutions of one of the metals
• This is easily seen as the more reactive metal slowly?disappears?from the solution,?displacing?the less reactive metal
• For example, magnesium is a reactive metal and can displace copper from copper(II)sulfate solution:

Mg + CuSO₄→ MgSO₄?+ Cu

• The blue colour of the CuSO_4?solution?fades?as colourless magnesium sulfate solution is formed
• Copper coats the surface of the magnesium and also forms solid metal which falls to the bottom of the beaker

Diagram showing the colour change when magnesium displaces copper from copper(II) sulfate

Other displacement reactions

Metal Solutions Displacement Table

轉載自savemyexam