Question 1: Define molten electrolysis and explain how it differs from aqueous electrolysis.

Answer: Molten electrolysis is the process of passing an electric current through a molten (liquid) ionic compound to decompose it into its elements. Unlike aqueous electrolysis, it involves no water and typically occurs at high temperatures, allowing the ionic compound to be in liquid form.

Question 2: Describe the role of electrodes in molten electrolysis.

Answer: Electrodes provide a conductive path for the electric current; the anode is positive and attracts anions for oxidation, while the cathode is negative and attracts cations for reduction.

Question 1: Explain why ionic compounds need to be in molten state for electrolysis to occur.

Answer: Ionic compounds need to be molten so that their ions are free to move and conduct electricity. In solid form, ions are fixed in a lattice and cannot move to carry current.

Question 2: Identify which ion is reduced at the cathode during the electrolysis of aluminium oxide (Al₂O₃).

Answer: Al³⁺

Question 1: Calculate the mass of aluminium produced when 96000 coulombs of charge are passed during the electrolysis of aluminium oxide. (Charge of 1 mol of electrons = 96485 C, 2 electrons are needed to reduce 1 Al³⁺ ion).

Answer: Mass of Al = (Q / (n × F)) × molar mass of Al = (96000 / (3 × 96485)) × 26.98 g ≈ 0.88 grams

Question 1: List three safety precautions that should be taken when performing molten electrolysis experiments.

Answer: Use heat-resistant gloves and eye protection, ensure proper ventilation due to high temperatures, and handle molten substances with appropriate tools to prevent burns.

Question 2: Identify the variables that need to be controlled during a molten electrolysis experiment.

Answer: Temperature, voltage applied, and concentration of the ionic compound.

Question 1: During the electrolysis of molten sodium chloride, the volume of chlorine gas evolved at the anode is measured over a period of time. Describe the trend you would expect in the volume of chlorine gas if the current remains constant.

Answer: The volume of chlorine gas would increase proportionally with time, indicating a direct relationship between current and gas production, assuming no gas escapes or reactions occur.

Question 1: Explain how molten electrolysis is used in the extraction of aluminium from its ore, bauxite.

Answer: In the extraction of aluminium, aluminium oxide is first purified and then melted. An electric current is passed through the molten oxide, causing aluminium ions to be reduced at the cathode to form aluminium metal, while oxygen is evolved at the anode. This process allows aluminium to be separated from its ore efficiently.

Question 2: Identify a modern industry or application that relies on molten electrolysis and briefly describe its importance.

Answer: The aluminium industry relies on molten electrolysis to produce aluminium metal, which is vital for manufacturing aircraft, packaging, and construction due to its lightweight and corrosion-resistant properties.