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Secondary revision · Chemistry Form 3

Redox Reactions

Question 1 of 12 Grade: Form 3
Q1
Consider the reaction equation below: 2Na(s) + 2HCl(aq) → 2NaCl(aq) + H₂(g). The reaction can be classified as...
Choose an answer, then submit to see the explanation.

About this topic

Learners will identify oxidation and reduction processes in terms of electron transfer and changes in oxidation states. This topic covers writing half-equations and balancing redox reactions. It develops analytical skills crucial for understanding processes like corrosion and electrolysis. Proficiency in redox is essential for tackling challenging sections of the ECZ chemistry paper and is a key learning outcome in the competence-based Zambian curriculum.

What you'll practise (12 questions)

  1. Identify the substance being oxidized in the reaction: Zn + Cu²⁺ → Zn²⁺ + Cu
  2. Which change is chromium (II) oxide, CrO₂, reduced?
  3. What colour change is observed when chlorine gas is bubbled through iron (II) chloride?
  4. Which one of the following pairs can behave as both reducing and oxidising agents? A) Calcium and Sulphur dioxide B) Calcium and Hydrogen peroxide C) Sodium and Hydrogen D) Sulphur dioxide and Hydrogen
  5. In which equation is the underlined substance acting as an oxidising agent? A) Fe³⁺(aq) + Al(s) → Fe(s) + Al³⁺(aq) B) 2I⁻(aq) + Cl₂(g) → I₂(s) + 2Cl⁻(aq) C) 3CO(g) + Fe₂O₃(s) → 2Fe(l) + 3CO₂(g) D) N₂(g) + 3H₂(g) → 2NH₃(g)
  6. What do we call the reaction involved when solution P (copper(II) sulphate) reacts with iron to form solution R and solid S?
  7. Which equation does not represent a redox reaction?
  8. Consider the reaction equation below: 2Na(s) + 2HCl(aq) → 2NaCl(aq) + H₂(g). The reaction can be classified as...
  9. An acidic gaseous reducing agent is passed through an aqueous solution of X. The solution changes from purple to colourless. What could X be?
  10. Dry ammonia was passed over heated copper II oxide as shown. What type of change occurs?
  11. Which of the following represents a redox reaction?
  12. Nitric Acid (HNO₃) is manufactured by the Ostwald Process starting with Nitrogen (N₂) as a raw material. Which graph represents the change in oxidation state of Nitrogen?

Answer each question above to see the correct answer and a full explanation.