Question 1: Define 'metal ore' and explain its role in the extraction process.

Answer: A mineral from which a metal can be economically extracted; it contains metal compounds or elements that are processed to obtain pure metal.

Question 2: Describe the main difference between pyrometallurgy and hydrometallurgy in metal extraction.

Answer: Pyrometallurgy involves high-temperature smelting to extract metals, while hydrometallurgy uses aqueous solutions to leach out metals from ores.

Question 3: What is the reactivity series, and how does it influence the method used to extract a metal?

Answer: The reactivity series ranks metals by reactivity; more reactive metals require electrolysis or reduction with carbon, while less reactive metals can be extracted by heating with carbon.

Question 1: If 50 grams of bauxite ore (mainly aluminum oxide) contains 45% Al₂O₃ by mass, calculate the amount of aluminum oxide in grams present in the ore.

Answer: 22.5 grams

Question 2: A smelting process requires 2000 kJ of energy to extract 1 kg of metal from its ore. How much energy is needed to extract 5 kg of metal?

Answer: 10,000 kJ

Question 1: List three safety precautions that should be taken when performing metal extraction processes such as smelting or electrolysis.

Answer: Wearing protective goggles and gloves, working in a well-ventilated area, and ensuring proper handling of chemicals and high-temperature equipment.

Question 2: Describe a basic experimental setup to test the reactivity of a metal with acid, including variables to control.

Answer: Set up a test tube with a small piece of metal and add a fixed volume of dilute acid. Control variables include temperature, acid concentration, and metal size. Observe for bubbling or gas formation to assess reactivity.

Question 1: A student observes that zinc reacts vigorously with hydrochloric acid, producing hydrogen gas, while copper shows no reaction under the same conditions. Explain this difference based on their positions in the reactivity series.

Answer: Zinc is more reactive and can displace hydrogen from acids, while copper is less reactive and does not react under these conditions.

Question 2: In a series of experiments, a metal oxide is reduced using carbon at high temperature. The metal is obtained with high purity. What does this suggest about the metal's position in the reactivity series?

Answer: The metal is less reactive than carbon and can be reduced by carbon, indicating it appears below carbon in the reactivity series.

Question 1: Explain how the Hall-Héroult process is used to extract aluminum on an industrial scale, including the principle behind electrolysis.

Answer: The Hall-Héroult process involves dissolving aluminum oxide in cryolite and passing an electric current through it. The electrolysis reduces aluminum ions to pure aluminum metal at the cathode, enabling large-scale extraction from bauxite ore.

Question 2: Describe one environmental concern associated with metal extraction processes and a possible mitigation strategy.

Answer: Environmental concern: pollution from mining and smelting emissions. Mitigation: implementing pollution control devices and recycling metals to reduce mining.