electrolysis

• what is electrolysis and how is it done


  . breaking down of substance using electricity

  
  

  . electric current passed through electrolyte causing it to decompose
• what is a electrolyte

  molten/dissolved ionic compound
• what occurs during electrolysis


  oxidation (loss of electrons) and reduction (gain of electrons)
• where do the positive ions in electrolyte move towards

  the cathode (negative electrode) and are reduced
• where do the negative ions in electrolyte move towards

  anode (positive electrode) and are oxidised
• what happens to ions as they lose/gain electrons

  form uncharged substances and discharged from electrolyte
• what are half equations


  they show how electrons are transferred during reactions
• how to write half equations

  . put thing being oxidised/reduced on 1 side and the thing it is oxidised/reduced to on the other

  . balance out the atoms

  . add electrons (e-) to balance charges
• what is a electrochemical cell made up of (5)


  a circuit made from:

  . anode

  . cathode

  . electrolyte

  . power source

  . wires that connect 2 electrodes
• how to set up electrochemical circuit if electrolyte is a solution(6)

  . get 2 inert electrodes (graphite/platinum)

  
  

  . clean surfaces of electrode with emery paper

  
  

  . dont touch surface of electrode with hands

  
  

  . place electrodes in beaker with electrolyte

  
  

  . connect electrodes to power supply using crocodile clips/wires

  
  

  . when you turn on power supply, current will flow through cell
• how to set up electro chemical cell if electrolyte is molten ionic substance (5)

  . put solid ionic substance in crucible

  . heat crucible with bunsen burner until solid molten. Do in fume cupboard so you dont release toxic fumes in room

  . when molten, dip 2 clean inert electrodes into electrolyte

  . connect electrodes to power supply using wires/clips

  . current will flow through cell when power turns on