Electrolysis GCSE EDEXCEL Notes

Electrolysis Definition : Is the process where ionic compounds is split (broken down) by the use of electricity. For the Ionic Compound to be electrolysed it has to be either in Molten state ( changed into liquid by heating) or in Aqueous form ( dissolved in water ). Note that the Ionic compound can not be in solid form otherwise it can not be broken down. When the ionic compound is broken down it forms the two ions from which the ionic compound was originally formed. Later the Ions will be oxidised or reduced to form atoms For Example Electrolysis of molten aluminium oxide breaks aluminium and oxygen. Electrolytes : As we mentioned The electricity has to pass in a liquid , this liquid is called an electrolyte , The liquid can be a molten ionic compound or dissolved ionic compound in water (aqueous). In either case it is the free ions which conduct the electricity .   Principle of Electrolysis: Electrolysis is based on an electrical circuit made of an electrolyte , a source of electricity and two electrodes An Electrode is solid rod that conducts electricity and is placed partially in the electrolyte  When electrolysis starts the ionic compound (the electrolyte) is broken down into the ions and the ions start moving towards the electrode with the opposite charge. This helps the electricity to move in the circuit. The Positive ions (cations) move to the Negative electrode (the Cathode) and gain an electron to become an atom. The Negative ions (Anions) move to the Positive electrode (the Anode) and lose an electron to become an atom.