When lead powder is added to copper chloride solution, a displacement reaction occurs and solid copper is formed.

i) Write the equation for the reaction.

ii) Why does the displacement reaction occur?

Take two conical flasks. Label them as I and II. Take a small amount of copper sulphate solution in the first conical flask. Take a small amount of granulated zinc in the second conical flask. Allow the copper sulphate solution to react with the zinc.

i) Name the type of reaction.

ii) Say whether the metal zinc is more reactive or less reactive.

iii) Write the complete and balanced reaction.

iv) Say whether this change is reversible or irreversible.

Relate the information given in all the four columns of the table.

When zinc and copper (II) sulphate are heated together, the following redox reaction occurs:

Zn + CuSO₄→ ZnSO₄ + Cu

(s) (aq) (aq) (s)

i) What does the word redox stand for?

ii) Show how electrons are transferred in the reaction.

iii) Write the ionic equation for the redox reaction.

If a substance gains oxygen during a reaction, it is being oxidized. If it loses oxygen, it is being reduced. Oxidation and Reduction always take place together, so that if one substance is oxidized, another is reduced. Using this idea, say which substance is oxidised and which substance is reduced in each reaction.

i) Mg + O₂→ 2MgO

(s) (g) (s)

ii) ZnO + C →Zn + CO

iii) Fe₂ O₃+ 3CO →2Fe + 3CO₂

iv) Cr₂O₃ + 2Al → + 2Cr + Al₂O₃