Electrolysis

• Electrolysis

  The decomposition of an ionic compound, when molten or in aqueous solution, by the passage of an electric current
• electrode: solid that conducts electricity placed in the electrolyte
• Electrolyte

  Molten or aqueous substance that undergoes electrolysis
• In electrolysis, the positive ions move towards the negative electrode (cathode) and the negative ions move to the positive electrode (anode).
• An anode is the positive electrode where electrons are lost (oxidation)
• A cathode is the negative electrode where electrons are gained (reduction)
• Metals can be extracted from their ores through electrolysis.
• metals or hydrogen are formed at the cathode and non-metals are formed at the anode
• metal objects are electroplated to improve their appearance and resistance to corrosion
• anode: long stripe

  
• flow of electrons in the external circuit: negative terminal(then to cathode then to anode then) to positive terminal
• pos ions (cations) move towards the cathode (non-metal ions)
• neg ions (anions) move towards the anode (metal or H+ ions)
• molten lead (II) bromide (PbBr2)

  • cathode: Pb2+ + 2e- ->Pb [reduction]
  • anode: 2Br- ->Br2 + 2e- [oxidation]
• Concentrated Aqueous Sodium Chloride (NaCl)

  • cathode: 2H+ + 2e- ->H2 [fuel]
  • anode: Cl- -> Cl2 + 2e [treat water and kill bacteria]
  • left over= Na+OH- [soap]