Redox, extraction of iron and transition metals

• What type of reactions are involved in the extraction of metals from ores?

  Redox reactions
• What is oxidation in terms of electron transfer?

  Loss of electrons from a substance
• What happens during reduction?

  Gain of electrons by a substance
• What is the chemical equation for magnesium oxidizing with oxygen?

  2Mg + O₂ → 2MgO
• What is a redox reaction?

  A reaction involving oxidation and reduction
• What is the role of the oxidising agent?

  Chemical that causes oxidation
• What does the reducing agent do?

  Causes reduction by removing oxygen
• What is the thermite reaction?

  A displacement reaction producing iron
• What is the chemical equation for the thermite reaction?

  2Al + Fe₂O₃ → 2Fe + Al₂O₃
• In the thermite reaction, what happens to aluminium?

  Aluminium is oxidised
• What is the oxidising agent in the thermite reaction?

  Iron(III) oxide
• What is the reducing agent in the thermite reaction?

  Aluminium
• What are the key characteristics of transition metals?

  • High melting points
  • High densities
  • Form coloured compounds
  • Act as catalysts
• What is the significance of redox reactions in metal extraction?

  • Essential for extracting metals from ores
  • Involves electron transfer processes
  • Key in processes like blast furnace operations
• What type of reactions are involved in the extraction of metals from ores?

  Redox reactions
• What is the role of transition metals?

  They form coloured compounds and act as catalysts
• What is the main component of iron ore haematite?

  Iron(III) oxide, Fe₂O₃
• What must be removed from iron(III) oxide to obtain iron?

  Oxygen
• What is the function of coke in the blast furnace?

  Used as a fuel and reacts to form carbon monoxide
• What does limestone do in the blast furnace?

  Helps remove acidic impurities by forming slag
• What does air provide in the blast furnace process?

  Oxygen for coke combustion
• Why is carbon more reactive than iron?

  It can displace iron from iron(III) oxide
• What is the first step in the blast furnace reaction?

  Hot air reacts with coke to produce CO₂
• What is produced when carbon dioxide is reduced in the blast furnace?

  Carbon monoxide
• What happens to iron(III) oxide in the blast furnace?

  It is reduced to iron
• What is the equation for the reduction of iron(III) oxide with carbon?

  2Fe₂O₃ + 3C → 4Fe + 3CO₂
• What is the significance of the blast furnace being a continuous process?

  It reduces cost and energy for reactions
• What does calcium carbonate decompose into when heated?

  Calcium oxide and carbon dioxide
• What is produced when calcium oxide reacts with silica?

  Calcium silicate (slag)
• What type of reaction occurs between calcium oxide and silica?

  Neutralisation reaction
• Why is calcium oxide considered basic?

  It reacts with acids to form salts
• What are the key factors in choosing a blast furnace site?

  Proximity to coast, transport, and housing
• Why should a blast furnace be away from built-up areas?

  To minimize noise and pollution impact
• What are the raw materials used in the blast furnace process?

  • Iron ore (haematite): Iron(III) oxide (Fe₂O₃)
  • Coke: Carbon (C)
  • Limestone: Calcium carbonate (CaCO₃)
  • Air: Oxygen (O₂)
• What are the steps involved in the extraction of iron in a blast furnace?

  1. Hot air reacts with coke to produce CO₂.
  2. CO₂ is reduced to CO by more coke.
  3. Iron(III) oxide is reduced to iron.
  4. Calcium carbonate decomposes to calcium oxide.
  5. Calcium oxide reacts with silica to form slag.
• The blast furnace

  
• What are redox reactions involved in?

  Extraction of metals from ores
• How is iron extracted in the blast furnace?

  By reduction through redox reactions
• What are the common properties of transition metals?

  • Form colored compounds
  • Good conductors of heat and electricity
  • Malleable
  • Less reactive than alkali metals
  • High melting points (except mercury)
  • Hard and tough
  • High densities
  • Can form ions with different charges
• What ions can iron form?

  Fe$^{2+}$ and Fe$^{3+}$