electrolysis

• what is the name of the positive electrode?

  anode
• what is the name of the negative electrode?

  cathode
• In electrolysis, which direction do the electrons travel?

  anode to cathode
• Which ions are attracted to the negative electrode (cathode) during electrolysis?

  positive
• The electrodes in an electrolysis cell are normally made of inert carbon. What does the term 'inert' mean?

  unreactive
• In electrolysis, is the ion that gains electrons oxidised or reduced?

  reduced
• In the electrolysis of molten lead bromide, what is the product at the anode?

  bromine
• In electrolysis, why does the compound you're trying to separate need to be molten or dissolved?

  so electrons are free to move to the electrode
• Which two of the following chemical processes are used to extract metals from their ores?

  electrolysis

  reduction with carbon
• How is a metal extracted from a metal compound using electrolysis?

  A compound is split into its elements using electricity
• Why is electrolysis not used to extract all metals?

  Electrolysis is expensive because it requires a large amount of electricity
• When should a metal be extracted by carbon reduction?

  When the metal is less reactive than carbon
• Reactivity series

  potassium

  sodium

  calcium

  magnesium

  aluminium

  carbon

  zinc

  iron

  tin

  lead

  hydrogen

  copper

  silver

  gold
• Why is electrolysis used to extract aluminium from its ores?


  it is more reactive than carbon
• What is the name of the substance that is mixed with things to lower its melting point?

  cryolite
• Rule at anode

  It will always be the OH-, unless there is a halide ion (such as Cl-, or Br-) present
• Rule at cathode

  least reactive is displaced
• In the electrolysis of an aqueous solution, which two ions are present from the water molecules themselves?

  H+ ions and OH- ions