Electrolysis

• Electrolysis is the use of an electrical current to breakdown compounds containing ions into their constituent components.
• Electrolyte is the substance being broken down by electrolysis.
• The electrodes are made from solids that conduct electricity.
• Oxidation is when electrons are lost, so atoms gain charge.
• Anode is the positive electrode.
• Cathode is the negative electrode.
• negatively charge ions move to anode (positive electrode)
• positively charged ions move to the cathode
• Electrolytes are substances which can carry electric current because they contain free ions.
• The ions are discharged at electrodes to produce elements
• Electrolysis can separate ionic compounds into elements
• Lead bromine can be split into lead and bromine by: The lead bromine being heated until it melts, positively charged lead ions move to negative electrode (cathode), here they gain electrons to form lead atoms (pure lead is produced at the cathode) , the negatively charged bromine atoms move to the positive electrode (anode),, here they loose electrons to from bromine atoms , they join together to form bromine molecules = bromine is released at this electrode.
• Splitting lead bromine is done by: lead bromine being heated until it melts. The positively charged lead ions move to the negative electrode (cathode) here they gain electrons which forms pure lead atoms.
• The negatively charged bromine ions move to the positive electrode (anode). Here they loose electrons to form bromine atoms, they join together to form bromine molecules.
• Ionic substances can only conduct electricity when they are molten or dissolved in water
• metals that are more reactive than carbon can be extracted from their ores using electrolysis.
• Electrolysis requires lots of heat and electrical energy making it an expensive process.
• Aluminium is obtained by the electrolysis of aluminium oxide that has been mixed with cryolite.
• Cryolite= a compound of aluminium
• Cryolite lowers the melting point of aluminium oxide meaning less energy is needed.
• Aluminium forms at the negative elctrode
• Oxygen gas forms at the positive carbon electrode and reacts with the carbon forming carbon dioxide .This wears away the positive electrode wish is replaced regularly.
• When ionic compound are dissolved in water to form aqueous solutions it ti slightly harder to predict the products of electrolysis.