Electrolysis

• When an ionic compound is melted or dissolved in water, the ions are free to move about within the liquid or solution
• An electrolyte is and ionic compound that is melted or dissolved in water and it can conduct electricity
• Passing an electric current through electrolytes causes the ions to move to the electrodes
• Positively charged ions move to the negative electrode (cathode)
• Negatively charged ions move to the positive electrode (anode)
• Ions are discharged at the electrodes producing elements
• Electrolysis is the process of breaking down a compound using electricity
• During electrolysis, at the cathode (negative electrode), positively charged ions gain electrons and so the reactions are reductions
• At the anode (positive electrode), negatively charged ions lose electrons and so the reactions are oxidations
• Reactions at electrodes can be represented by half equations, for example

  • 2H$^+$ + 2e$^-$ → H$_2$ cathode
  • 4OH$^-$ → O$_2$ + 2H$_2$O + 4e$^-$ anode