Similarities: ï· The electrolyte is the substance that conducts electricity within the cell. Electric charge is carried by anions to the anode and by cations to the cathode. ï· The electrode where oxidation occurs is called the anode. ï· The electrode where reduction occurs is called the cathode. ï· In the external circuit, electrons travel through the wire from the anode to the cathode. Key ideas of electrolysis: The products of electrolysis depend on: ï· The reactivity of the ions present ï· The type of electrode used ï· The concentration of the reactants ï· The amount of current used ï· The temperature e.g. molten NaCl produces Na and Cl2 dilute aqueous NaCl produces H2 and O2 (as for H2O) For electrolytic cells: ï· Oxidation takes place at the anode (sign +ve) ï· Reduction takes place at the cathode (sign âve) ï· Electrons flow from the anode to the cathode ï· Electric current is used to cause a chemical reaction ï· The applied voltage must be greater then the voltage of the cell ï· If more than one reaction is possible the following rules apply Metal ions: Whether a metal is produced depends on its position in the reactivity series relative to the position of water. In a concentrated solution the metal will form if it is below water in the activity series. If it is above water, hydrogen gas forms. If there are 2 possible products, the one lower on the activity series will form. Non-Metal ions: A simple ion will always form its element. If a polyatomic ion is present, oxygen will form in preference.