Question 1: Define electrolysis and explain its role in extracting aluminium from bauxite ore.

Answer: Electrolysis is a chemical process that uses an electric current to break down compounds into their elements. In aluminium extraction, electrolysis is used to reduce aluminium oxide (alumina) into pure aluminium metal.

Question 2: What is the main raw material used in the industrial extraction of aluminium, and what compound is it primarily processed into before electrolysis?

Answer: The main raw material is bauxite ore, which is processed into aluminium oxide (alumina) before electrolysis.

Question 3: Describe the role of cryolite in the industrial extraction of aluminium.

Answer: Cryolite acts as a solvent to lower the melting point of alumina, making electrolysis more energy-efficient and feasible at lower temperatures.

Question 4: Explain why renewable energy sources are increasingly important in the electrolysis-based extraction of aluminium.

Answer: Renewable energy sources reduce carbon emissions associated with electricity generation, making aluminium production more sustainable and environmentally friendly.

Question 1: Calculate the amount of electric charge (in coulombs) required to produce 10 kg of aluminium, given that 1 mole of aluminium (26.98 g) requires 3 Faradays of charge. Use Faraday's constant (F) = 96485 C/mol.

Answer: Total moles of Al = 10000 g / 26.98 g/mol ≈ 370.6 mol Charge needed = 370.6 mol × 3 F × 96485 C/mol ≈ 107,161,839 C

Question 2: If the electrolysis cell operates at a constant current of 200,000 A, how long (in hours) will it take to produce 10 kg of aluminium?

Answer: Time (seconds) = Total charge / Current = 107,161,839 C / 200,000 A ≈ 535.8 seconds; in hours ≈ 0.149 hours.

Question 1: List three safety precautions that should be taken when performing electrolysis in a laboratory setting.

Answer: Wear protective goggles and gloves, ensure proper ventilation, and handle electrical equipment carefully to prevent shocks.

Question 2: Identify and explain two variables that can affect the efficiency of aluminium electrolysis.

Answer: Variables include the temperature of the electrolysis cell, which affects resistance and reaction rate, and the purity of alumina, which impacts electrical conductivity.

Question 1: A plant aims to reduce its carbon footprint by using 100% renewable energy for electrolysis. Explain how this change could impact the environmental sustainability of aluminium production.

Answer: Using 100% renewable energy in aluminium electrolysis significantly reduces greenhouse gas emissions associated with electricity generation. This shift makes aluminium production more sustainable, decreases dependence on fossil fuels, and aligns the industry with global efforts to combat climate change.

Question 2: Suppose an industrial process reports a 15% decrease in energy consumption after upgrading to more efficient electrolysis technology. Discuss the potential economic and environmental benefits of this improvement.

Answer: A 15% decrease in energy consumption reduces operational costs, making aluminium production more economically viable. Environmentally, it results in lower greenhouse gas emissions and less strain on energy resources, contributing to more sustainable industry practices and reduced ecological impact.