Iron compounds. Cast iron
Answers are for parents and teachers.
1
Write the equations for the changes Fe → FeCl₃ → Fe(OH)₃ → Fe₂O₃.
2Fe + 3Cl₂ → 2FeCl₃; FeCl₃ + 3NaOH → Fe(OH)₃↓ + 3NaCl; 2Fe(OH)₃ → Fe₂O₃ + 3H₂O.
2
How many grams of iron are in 800 g of Fe₂(SO₄)₃ (M = 400)? (A(Fe) = 56)
224
3
How many grams of Fe are obtained when 464 g of Fe₃O₄ is reduced with CO in a blast furnace? (M(Fe₃O₄) = 232, A(Fe) = 56)
336
4
Describe the effect of the blast-furnace process on the environment and ways to reduce it.
Dust, toxic gases, slag and waste water; filters, waste-free technology, making sponge iron with H₂ or natural gas instead of coke.
5
What is the role of iron in haemoglobin and what can happen if it is lacking?
It carries oxygen; a lack can cause anaemia — see a doctor.