Iron
Answers are for parents and teachers.
1
Write the equations for the changes Fe → FeCl₂ → Fe(OH)₂.
Fe + 2HCl → FeCl₂ + H₂↑; FeCl₂ + 2NaOH → Fe(OH)₂↓ + 2NaCl.
2
How many grams of Cu are deposited when 112 g of Fe reacts with CuSO₄ solution? (A(Fe) = 56, A(Cu) = 64)
128
3
Why does Fe + Cl₂ give FeCl₃ but Fe + HCl give FeCl₂?
Chlorine is a strong oxidiser and takes iron to +3; H⁺ is weaker and takes it only to +2.
4
Write the equation for the formation of iron scale Fe₃O₄.
3Fe + 2O₂ → Fe₃O₄
5
Name two ways of protecting iron objects from rust.
Painting/oiling; coating with zinc or chromium.