Oxygen & REDOX Reactions

  • Oxidation and reduction involve the addition or removal of oxygen from a substance and are called redox reactions.
  • Oxidation is a reaction in which:
    • oxygen is added to an element or a compound.
    • an element, ion or compound loses electrons.
  • Reduction is a reaction in which:
    • oxygen is removed from an element or a compound.
    • an element, ion or compound gains electrons.
  • Metals react with oxygen in the air to produce metal oxides.
  • A common example is the reaction with red-brown copper metal to produce black copper oxide:

2Cu + O2 ⟶ 2CuO

  • In this reaction copper metal has been oxidised since oxygen has been added to it.
  • Another example is the reaction of zinc oxide with carbon:

ZnO + C ⟶ Zn + CO

  • In this reaction the zinc oxide has been reduced since it has lost oxygen. The carbon atom has been oxidised since it has gained oxygen.

AQA GCSE Chemistry Notes

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Morgan Curtin Chemistry

Author: Morgan

Morgan’s passion for the Periodic Table begun on his 10th birthday when he received his first Chemistry set. After studying the subject at university he went on to become a fully fledged Chemistry teacher, and now works in an international school in Madrid! In his spare time he helps create our fantastic resources to help you ace your exams.