Question 1: Define oxidation in terms of electron transfer.

Answer: Oxidation is the loss of electrons by a substance during a chemical reaction.

Question 2: Explain the difference between oxidation and reduction in terms of oxidation states.

Answer: Oxidation involves an increase in oxidation state, while reduction involves a decrease.

Question 3: Identify the oxidising agent in the reaction: 2Fe + 3Cl₂ → 2FeCl₃.

Answer: Chlorine (Cl₂) is the oxidising agent.

Question 4: Describe what is meant by the term 'oxidation state'.

Answer: Oxidation state is the hypothetical charge an atom would have if all bonds were ionic.

Question 1: Calculate the oxidation state of manganese in KMnO₄.

Answer: The oxidation state of Mn in KMnO₄ is +7.

Question 2: In a reaction, 2 grams of zinc (Zn) are oxidised. How many electrons are transferred if 1 mole of zinc loses 2 electrons? (Atomic mass of Zn = 65.38 g/mol)

Answer: Number of electrons transferred = (2 g / 65.38 g/mol) × 2 = approximately 0.061 mol of electrons.

Question 1: Describe a basic experimental setup to demonstrate oxidation of magnesium metal.

Answer: Place magnesium ribbon in a crucible, heat with a Bunsen burner in a fume cupboard, observe the bright white flame and formation of magnesium oxide.

Question 2: List two safety precautions that should be taken when heating metals in a laboratory.

Answer: Wear safety goggles and conduct the experiment in a well-ventilated area or fume cupboard.

Question 1: A series of metals (zinc, iron, copper) are added to dilute hydrochloric acid. The time taken for each metal to react completely is recorded. Zinc reacts fastest, then iron, then copper. Explain this trend in terms of reactivity and oxidation.

Answer: Zinc has the highest reactivity and readily loses electrons to form Zn²⁺ ions, making it react faster. Iron is less reactive, and copper is less reactive, so it reacts slowly or not at all.

Question 1: Explain how the reactivity series of metals relates to their tendency to undergo oxidation. Use examples to support your answer. (6 marks)

Answer: The reactivity series ranks metals based on their ability to lose electrons and undergo oxidation. Highly reactive metals like potassium and sodium readily oxidise, reacting quickly with acids and water, while less reactive metals like gold and platinum resist oxidation. This trend is due to their atomic structure and ionisation energies.

Question 1: Describe how the process of galvanisation protects iron from rusting. Include the concepts of oxidation and reduction in your explanation.

Answer: Galvanisation involves coating iron with zinc. Zinc acts as a sacrificial anode, oxidising (corroding) instead of iron when exposed to moisture, thus preventing rusting. The zinc undergoes oxidation, while the iron remains protected.