extracting metals and equilibria topic 4

• reactivity series is a list of elements in order of increasing reactivity
• reactivity series:

  1. Potassium
  2. sodium
  3. calcium
  4. magnesium
  5. Aluminium
  6. Carbon(non-metal)
  7. zinc
  8. iron
  9. hydrogen(non-metal)
  10. copper
  11. silver
  12. gold
• Reactivity is a measure of how easily metals lose electrons to become cations.(positive ions).
• The metals near the top of the series are more likely to lose electrons and become cations.
• more reactive the metal the easier it finds to lose its electrons
• We can test the reactivity of metals by placing them in water or dilute acids.

  Metals of the same mass and surface area are placed in the water or acid for the same amount of time.

  For example, when magnesium, zinc and copper are placed in dilute acid, bubbles may be produced.

  The more bubbles that are produced, the more reactive the metal.
• displacement reaction is a chemical reaction in which a more reactive element displaces a less reactive element from its compound
• iron oxide + magnesium -> magnesium oxide + iron why does this happen?

  magnesium more reactive than iron so replaces it
• potassium oxide + zinc -> no reaction


  zinc is less reactive than pottasium so doesn't replace it
• Oxidation means the loss of electrons (Oxidation Is Loss).
• Reduction means the gain of electrons (Reduction Is Gain).
• redox reactions.


  Reactions where Oxidation and reduction can happen at the same time.
• OIL RIG
• ore 


  rock that contains enough metal compounds to make it worthwile to extract the metal
• What reaction is used to extract metal ores?

  Displacement reactions
• Extraction is when you obtain metals from ore
• Where are most metals extracted from found

  in earth's crust
• most metals are found in compounds as metal oxides so an ore is needeed to extract it
• Metals higher than carbon in the reactivity series have to be extracted by?

   electrolysis.
• Phytoextraction

  1. Includes growing plants that absorb metal compounds on low grade ores
  2. plants are burned to create ash from which metal is extracted
• There are some alternative biological methods of extracting metals from their ores

  Two of these methods are bacterial extraction and phytoextraction.
• Bacterial extraction(Biobleaching)

  1. Uses bacteria grown on low grade ores
  2. leachate(solution containing copper ions) is produced
  3. Copper is extracted from leachate by displacement using scrap ions, then purified by electrolysis
• Bacterial extraction can be used for metals such as nickel,cobalt and zinc
• Disadvantages of metal extraction using biological process

  • takes time for plants to grow
  • plant growth depends on weather
  • Phytoextraction is a slow process(plant roots only absorb metal compounds slowly)
  • In bacterial extraction, the leachate produced can contain toxic substances.
• Advantages of metal extraction using biological process

  • Doesn't need to be mined
  • Less greenhouse gases
  • saves high grade ores
• Reactive metals lose electrons easily to become positive ions.
• Metal atoms lose electrons to become positive ions.
• Metal + acid - salt + hydrogen
• Oxidation example equation

  2Mg + O2 - Mg2O
• Reduction reaction example

  2MgO - 2Mg + O2
• Carbon can be used to obtain metal from ores which are less reactive

  • Copper oxide + carbon - >carbon dioxide + copper
• Why do we find pure gold in the ground, but not pure iron?

  • Gold is unreactive with any elements
  • Iron is reactive it reacts with oxygen so it's oxidised to iron oxide
• all chemical reactions are reversible reactions . This means that the products can be changed back into the original reactants .
• Product life cycle


  1.extracting raw materials

  2.manufacturing and packaging

  3.Use and operation

  4.disposal
• 1.extracting raw materials(uses energy and damages environment) 2.manufacturing and packaging(use lots of energy create waste) 3.Use and operation 4.dispose(energy used)
• How to reduce energy,waste and negative environmental impacts

  Recycle,reuse and use fewer products
• recycling metals uses less energy than extracting them it's cheaper and better for environment
• What is purpose of life cycle assessment (LCA)


  To access environmental impact of products
• Reversible reactions are always endothermic and exothermic in one direction