Electrolysis

What the syllabus asks of you

• Define electrolysis as the decomposition of an 8 Describe the transfer of charge during ionic compound, when molten or in aqueous electrolysis to include: solution, by the passage of an electric current (a) the movement of electrons in the external
• Identify in simple electrolytic cells: circuit (a) the anode as the positive electrode (b) the loss or gain of electrons at the (b) the cathode as the negative electrode electrodes (c) the electrolyte as the molten or aqueous (c) the movement of ions in the electrolyte substance that undergoes electrolysis Core Supplement
• Identify the products formed at the electrodes 9 Identify the products formed at the electrodes and describe the observations made during the and describe the observations made during the electrolysis of: electrolysis of aqueous copper(II) sulfate using (a) molten lead(II) bromide inert carbon / graphite electrodes and when (b) concentrated aqueous sodium chloride using copper electrodes (c) dilute sulfuric acid using inert electrodes made of platinum or carbon / graphite
• State that metals or hydrogen are formed at the cathode and that non-metals (other than hydrogen) are formed at the anode
• Predict the identity of the products at each 10 Predict the identity of the products at each electrode for the electrolysis of a binary electrode for the electrolysis of a halide compound in the molten state compound in dilute or concentrated aqueous solution 11 Construct ionic half-equations for reactions at the anode (to show oxidation) and at the cathode (to show reduction)
• State that metal objects are electroplated to improve their appearance and resistance to corrosion
• Describe how metals are electroplated