Question 1: Molten electrolysis involves passing an electric current through a substance in its molten (liquid) state to cause chemical decomposition. This process is used to extract elements from their compounds when they cannot be isolated by other methods. It relies on the movement of ions towards electrodes where reduction or oxidation occurs.

Answer: Molten electrolysis is a process where an electric current passes through a liquid (molten) compound to decompose it into its elements, used for extracting metals when other methods are not feasible.

Question 1: Define electrolysis and explain why molten electrolysis requires the substance to be in a liquid state.

Answer: Electrolysis is a chemical decomposition caused by passing an electric current through a substance in a liquid state. It requires the substance to be molten because ions need to be free to move towards electrodes for the process to occur.

Question 2: Name the two electrodes involved in electrolysis and describe their roles.

Answer: The two electrodes are the cathode (where reduction occurs) and the anode (where oxidation occurs).

Question 1: Explain what happens at the cathode during the electrolysis of molten aluminium oxide.

Answer: At the cathode, aluminium ions gain electrons (are reduced) to form aluminium metal.

Question 2: Describe the process occurring at the anode in the electrolysis of molten sodium chloride.

Answer: At the anode, chloride ions lose electrons (are oxidised) to form chlorine gas.

Question 1: Calculate the amount of aluminium (in grams) produced when passing 96,000 Coulombs of charge through molten aluminium oxide. (Atomic mass of Al = 27 g/mol, 3 electrons per Al atom).

Answer: 36 grams

Question 1: Identify one industrial process that uses molten electrolysis and describe its purpose.

Answer: The Hall-Héroult process for extracting aluminium from bauxite ore.

Question 2: Explain why molten electrolysis is preferred over aqueous electrolysis for extracting metals like aluminium.

Answer: Molten electrolysis is preferred because in aqueous solutions, water can be reduced or oxidised, leading to side reactions and impure products. In molten form, only the ions of the compound are involved, resulting in pure metal extraction.

Question 1: List two safety precautions that must be taken when performing molten electrolysis in a laboratory setting.

Answer: Use appropriate protective equipment to prevent burns from high temperatures and ensure proper ventilation to avoid accumulation of hazardous gases.

Question 2: Describe the importance of controlling temperature during molten electrolysis.

Answer: Controlling temperature ensures the substance remains molten and prevents accidents or equipment damage due to overheating.