Electrolysis

• positive electrode = anode
• negative electrode = cathode
• a = electrolyte

  
• In electrolysis, which direction do the electrons travel

  • Anode ➔ Cathode
• Which ions are attracted to the negative electrode (cathode) during electrolysis:

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

  • It is unreactive, so will not take place in the reaction. 
• In the electrolysis of molten lead bromide, what is the product at the anode:

  • Bromine
  • because The Br- ions will go to the anode and be oxidised to Br2. 
• In electrolysis, which electrode would chloride ions (Cl-) be attracted to:

  • Anode
• b = cathode

  
• e = anode

  
• chemical processes are used to extract metals from their ores are:

  • Electrolysis
  • Reduction with carbon
• How is a metal extracted from a metal compound using electrolysis:

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

  • it is expensive
  • and requires a lot of energy
• a metal should be extracted by carbon reduction:

  • When the metal is less reactive than carbon
• Why is electrolysis used to extract aluminium from its ores:

  • because aluminium is more reactive then carbon therefore you cant use Reduction with carbon
• In the electrolysis of a solution, which two ions are present from the water molecules themselves:

  • OH-
  • H+
• In the electrolysis of aqueous solutions, what is the rule for determining which ion will be oxidised (lose electrons) at the anode (positive electrode)?

  • It will always be the OH-, unless there is a halide ion (such as Cl-, or Br-) present
• In the electrolysis of aqueous solutions, what is the rule for determining which ion will be reduced (gain electrons) at the cathode (negative electrode)?

  • It will always be the H+ ion, unless Cu2+ is present (another way of phrasing it would be that it is always the ion of the least reactive element)
• In the electrolysis of aqueous copper nitrate, Cu(NO3)2 (aq), which four ions would be present in the electrolyte?

  • Copper ions (Cu2+)
  • Nitrate ions (NO3-)
  • Hydrogen ions (H+)
  • Hydroxide ions (OH-)