Question 1: Aqueous electrolysis involves passing an electric current through water containing dissolved substances to decompose compounds into their elements or ions. This process is used in industries like metal refining and purification. Explain in your own words what occurs during aqueous electrolysis and why it is important.

Answer: During aqueous electrolysis, an electric current causes compounds in water to decompose into their constituent elements or ions. It is important because it allows for the extraction and purification of metals, production of chemicals, and treatment of waste water.

Question 1: Define electrolysis and describe the role of electrodes in this process.

Answer: Electrolysis is a chemical process where electric current causes a compound to decompose into elements or ions. Electrodes are conductors through which the electric current enters and leaves the electrolyte, facilitating the chemical reactions.

Question 2: What is the function of the anode and cathode during aqueous electrolysis?

Answer: The anode is the positive electrode where oxidation occurs, and the cathode is the negative electrode where reduction occurs.

Question 1: Calculate the amount of electric charge (in coulombs) needed to deposit 10 grams of aluminum (Al) during electrolysis. (Atomic weight of Al = 27 g/mol, valency = 3). Use the formula: Q = n × F, where n is moles of electrons, and F (Faraday's constant) = 96485 C/mol.

Answer: Q = 3 × 96485 × (10 / 27) ≈ 107,458 C

Question 2: If a current of 2 amperes is passed through an aqueous solution for 30 minutes, how many grams of a substance that requires 2 Faradays per mole to be deposited will be formed? (Use Faraday's constant = 96485 C/mol).

Answer: Total charge Q = 2 A × 1800 s = 3600 C; Moles deposited = 3600 / 96485 × 2 ≈ 0.0745 mol; mass = 0.0745 mol × molar mass (depends on substance).

Question 1: List three variables that can affect the efficiency of an aqueous electrolysis experiment and briefly explain how they influence the process.

Answer: Variables include voltage (higher voltage increases rate), electrode material (affects reaction efficiency), and temperature (higher temperature can increase reaction rate).

Question 2: Describe two safety precautions that should be taken when performing aqueous electrolysis in a laboratory setting.

Answer: Wear protective gloves and goggles to prevent chemical burns and splashes, and ensure proper ventilation to avoid accumulation of gases.

Question 1: In an electrolysis experiment, 0.5 mol of chloride ions (Cl-) are present in the solution. During electrolysis, chloride ions migrate towards the anode and produce chlorine gas. Explain how the concentration of chloride ions affects the amount of chlorine produced and what might happen if the concentration is very low.

Answer: Higher chloride ion concentration results in more chlorine gas production. If the concentration is very low, less chlorine will be generated, and the reaction may be inefficient or stop altogether.

Question 1: Describe how aqueous electrolysis is used in the industry to extract aluminum from bauxite ore.

Answer: In the Hall-Héroult process, alumina dissolved in molten cryolite is electrolyzed; aluminum metal forms at the cathode and is collected, while oxygen forms at the anode.

Question 2: Explain one technological advancement that has improved the efficiency or safety of aqueous electrolysis in industry.

Answer: The development of inert electrodes, such as platinum or graphite, reduces electrode degradation, improving safety and efficiency.

Question 1: Discuss the environmental implications of using aqueous electrolysis for metal extraction and waste treatment. Include potential benefits and challenges.

Answer: Aqueous electrolysis can reduce reliance on chemical reagents and produce pure metals, decreasing environmental pollution. However, it consumes significant energy and may generate harmful gases if not properly managed, posing challenges for sustainable use.