EDEXCEL IGCSE CHEMISTRY: DOUBLE SCIENCE 复习笔记:2.4.2 Metal Displacement Reactions

EDEXCEL IGCSE CHEMISTRY: DOUBLE SCIENCE 复习笔记:2.4.2 Metal Displacement Reactions

Metal Displacement Reactions

 

  • 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

 

Metal Oxide Displacement Table, downloadable IGCSE & GCSE Chemistry revision notes

 

 

 

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 CuSOsolution 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

 

 

Magnesium-copper displacement, IGCSE & GCSE Chemistry revision notes

 

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

 

 

 

Other displacement reactions

 

Metal Solutions Displacement Table

 

Metal Solutions Displacement Table, downloadable IGCSE & GCSE Chemistry revision notes

 

Exam Tip

Displacement reactions occur when the solid metal is more reactive than the metal that is in the compound.

转载自savemyexams

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