Topic 3 - Displacement Reactions and The Blast Furnace

• Metal Ores 


  • Ores are minerals found in the Earth's crust. They contain metal compounds from which metals can be extracted

  Examples:

  • Rock salt - from sodium chloride
  • Bauxite - from aluminium oxide
• The Reactivity Series

  Order - (reactivity decreasing)

  1. Potassium
  2. Sodium
  3. Magnesium
  4. Aluminium
  5. Carbon
  6. Zinc
  7. Iron
  8. Tin
  9. Lead
  10. Copper
  11. Silver
  12. Gold
• Extraction of Metals in the Reactivity Series

  • Gold and silver are metals that are found native
  • Most reactive metals (Potassium to Aluminium) can be extracted by electrolysis
  • Least reactive metals (Zinc to Copper) are displaced by using carbon
• Thermit Reaction

  Word equation: Iron oxide + Aluminium -> Iron + Aluminium oxide

  In terms of reactivity...

  • Aluminium is more reactive than iron
  • Aluminium is higher in the reactivity series
  • Aluminium displaces the Iron

  Key points of the Thermit Reaction:

  1. Observations: sparks and molten iron is formed
  2. Iron melts and is molten as this is an exothermic reaction
  3. Magnesium does not appear in the word equation as it doesn't take part in the reaction
  4. Magnesium is used as a fuse for safety - allows time to walk clear before the reaction starts
• Signs a Displacement reaction has taken place

  1. Colour change
  2. Solid forms
• Where to site an industrial plant

  1. Near a dock - to allow raw materials such as ores to be imported for production of metals
  2. Near a main road/motorway - to transport products and for workforce to be able to travel to and from work
  3. Power station nearby - source of reliable energy and to negotiate cheaper electricity prices
  4. Housing estates are far away - to avoid damage as there is a risk of an explosion/accident
• Alloys

  • An alloy is a mixture made by mixing molten metals
  • It's properties can be modified by changing it's composition
• Types of steel alloys

  1. Mild steel - made from elements carbon and iron
  2. Tool steel - made from elements tungsten and iron
  3. Stainless steel - made from elements chromium and iron
• Properties of the steel alloys

  • Mild steel is easy to bend and to pull into wires
  • Tool steel is hard and can be heated to high temperatures
  • Stainless steel is hard and does not rust easily
• Strength of alloys and making pure metals into alloys

  • Steel is much more stronger and harder than iron so it is more useful
  • The greater the percentage of carbon in an alloy results in lower tensile strength
  • Pure metals can be made harder by adding another element which forms an alloy
• Transition metals

  • Found in the centre of the Periodic Table
  • Contain several metallic properties including; high melting and boiling points, malleable, high density, good electrical and thermal conductivity
  • Many transition metals are useful catalysts

  Example: Iron in the manufacturing of ammonia and platinum in catalytic converters

  • Transition metals form more than one type of ion, for example: Fe^2+/Fe^3+ and their compounds are often coloured
• Testing for the presence of transition metal ions using sodium hydroxide


  1. Fe^2+ - pale green precipitate formed
  2. Fe^3+ - brown precipitate formed
  3. Cu^2+ - blue precipitate formed

  Ionic Equations:

  Iron(II): Fe^2+ (aq) + 2OH^- (aq) -> Fe(OH)2 (s)

  Iron(III): Fe^3+ (aq) + 2OH^- (aq) -> Fe(OH)3 (s)

  Copper: Cu^2+ (aq) + 2OH^- (aq) -> Cu(OH)2 (s)
• Oxidation and Reduction 


  Oxidation -

  • Gain of oxygen (loss of electrons)

  Reduction -

  • Loss of oxygen (gain of elecrtons)
• Uses and properties of Aluminium

  • Use: power cables for national grid
  • Properties: conducts electricity, low density and doesn't corrode
  • Use: aircraft wings
  • Properties: low density and doesn't corrode
  • Use: bike frames
  • Properties: strong, low density and doesn't corrode
• Uses and properties of copper


  • Use: copper saucepans
  • Properties: conducts heat, shiny, and doesn't corrode
  • Use: water pipes
  • Properties: doesn't corrode and is malleable
• Uses and properties of titanium

  • Uses: Hip replacements, helicopter rotor blades, and chemical pipes
  • Properties: inert(unreactive), strong, and malleable
• Raw materials added to The Blast Furnace

  Raw materials -

  • Iron ore: source of iron
  • Coke(carbon): used as a fuel and to produce carbon monoxide for the reduction
  • Limestone: to remove impurities (slag formation)
  • Hot air: provides oxygen so coke burns
• Process of The Blast Furnace

  1. Oxygen from the hot air reacts with carbon(coke) to form carbon monoxide. This is an exothermic reaction and heats the furnace
  2. Carbon monoxide reacts with iron(III) oxide to give iron [iron oxide reduces and carbon monoxide oxidises]
  3. Limestone decomposes thermally to form calcium oxide
  4. Calcium reacts with silicon dioxide (sand) to form slag

  Equations (in order):

  1. 2C + O2 -> 2CO
  2. Fe2O3 + 3CO -> 2Fe + 3CO2
  3. CaCO3 -> CaO + CO2
  4. CaO + SiO2 -> CaSiO3
• The Blast Furnace is a neutralisation reaction
• The process in The Blast Furnace is continuous, with new raw materials added and products removed all the time due to the time and cost to get the furnace up to temperature