electrolytic processes

• electrolysis is the process of using electricity to split water into hydrogen and oxygen. This reaction takes place in a unit called an electrolyser.

  
• reactictivity series :

  K, Na, Li, Ca, Mg, Al, C, Zn, Fe, H, Cu, Ag, Au

  
• the reactivity series shows how easily metals can be oxidised by acids or air (oxygen). The more reactive the metal, the higher up it will appear on the reactivity series.
• electrolysis = process in which electrical energy, from a direct current supply decomposes electrolytes
• cathode is negative and anion is positive
• ionic solution contain :

  • ion which make up the ionic compound
  • ions in water (OH+ and H+)
• • at cathode (-) : hydrogen is produced unless the ion is less reactive than hydrogen - then the ion is produced instead
  • at anode (-) : oxygen will be produced unless halogens are present (Cl-, Br-, I-)