Metal & Acid Reactions as Redox Reactions (AQA GCSE Combined Science: Trilogy): Revision Note Exam code: 8464

Metal & Acid Reactions as Redox Reactions (AQA GCSE Combined Science: Trilogy): Revision Note

Exam code: 8464

Metals & acid reactions as redox reactions

Higher tier only

  • Metal-acid reactions are redox reactions

  • Redox means reduction and oxidation at the same time

  • If we analyse the ionic equation for the reaction between zinc and hydrochloric acid:

Zn + 2HCl ⟶ ZnCl2 + H2

  • The ionic equation is:

Zn + 2H+⟶ Zn2+ + H2

  • This equation can be further split into two half equations illustrating oxidation and reduction individually:

Zn → Zn2+ + 2e–

2H+ + 2e–→ H2

  • The zinc atoms are thus oxidised as they lose electrons.

  • The hydrogen ions are thus reduced as they gain electrons.

  • Both reactions are occurring at the same time and in the same reaction chamber hence it is a redox reaction

Examiner Tips and Tricks

Remember metal atoms tend to lose electrons and in these reactions are usually the species that undergoes oxidation.


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