Reactivity series — Edexcel Linear - OL (Chemistry) Revision Notes & Topical Questions

Reactivity series Edexcel O Level Linear Chemistry: what to do next

These Reactivity series Edexcel O Level Linear Chemistry notes covered the key ideas, worked examples and exam technique for this topic. Check your Reactivity series Edexcel O Level Linear Chemistry understanding with the practice questions below, then reread any Reactivity series Edexcel O Level Linear Chemistry point you were unsure about before moving on.

Any metal displaces a less reactive metal from a solution of its salt, and the competition for electrons can be shown with ionic equations. Example prediction: will iron displace magnesium from magnesium sulfate? No, because iron is below magnesium. Will magnesium displace iron? Yes: Mg + FeSO₄ → MgSO₄ + Fe.

Reading the table down the columns gives the order Mg > Zn > Cu.

The more reactive the metal, the more stable its compounds to heat.

A test

• heat equal amounts of each carbonate and time how long it takes for limewater to turn cloudy;
  • the shorter the time, the less stable the carbonate and the less reactive the metal.

Iron rusts (hydrated iron(III) oxide) when in contact with both oxygen and water. In an experiment with nails in four tubes (air and water; boiled water with oil layer; dry air with calcium chloride; salt water), rust forms only where both are present and salt speeds it. Prevention methods:

Aluminium does not corrode obviously because its surface forms a thin, tough, adherent layer of aluminium oxide that protects the metal beneath, in spite of aluminium being high in the reactivity series.

The temperature rise in displacement reactions can rank metals.

The same pattern explains why a copper pipe can be joined to a steel tank only with care: the steel, the more reactive metal, will corrode faster when the two are in contact with water, which is the opposite of sacrificial protection.