Electrolysis

• Electrolysis is the use of an electrical current to break down compounds containing ions into their constituent elements
• The substance being broken down in electrolysis is called the electrolyte
• The electrodes are made from solids that conduct electricity
• An solid that conducts electricity is known as an electrode
• The electrolyte has to be a liquid so that the ions are free to move
• An electrolyte is a molten or dissolved ionic compound , so it conducts electricity
• For the electrolysis of molten ionic compounds, both electrodes must be inert (unreactive) so that they don't react with the electrolyte or products
• In electrolysis, the 2 electrodes are connected to a direct current supply
• The positive electrode is called the anode
• The negative electrode is called the cathode
• During electrolysis, negatively charged ions move to the anode
• During electrolysis, positively charged ions move to the cathode
• Electrolysis can be used to separate ionic compounds into elements
• When a current is passed through and electrolyte , the ions move to the electrodes

  
• Describe how the ionic compound, lead bromide can be split into lead and bromine using electrolysis?

  • The lead bromide is heated until it melts 
  • The positively charged lead ions move to the cathode (negative electrode) where they gain electrons to form lead atoms 
  • Pure lead is produced at this electrode
  • The negatively charged bromide ions move to the anode (positive electrode) where they lose electrons to form bromine atoms which join together to form bromine molecules 
  • Bromine is released at this electrode