1In the reaction 2FeCl₃(aq) + H₂S(g) → 2FeCl₂(aq) + 2HCl(g) + S(s), which element is oxidised?
2Which of the following equations does NOT represent a redox reaction?
3When a metal atom becomes an ion, what process occurs?
4In the reaction of chlorine with sodium hydroxide: Cl₂(aq) + 2NaOH(aq) → NaCl(aq) + NaClO(aq) + H₂O(l), which substance behaves as the reducing agent?
5What is the colour change that occurs when chlorine gas is bubbled into an aqueous solution of potassium iodide?
6For endothermic reactions, which statements are true? I. The enthalpy change is positive. II. Heat is evolved during the reaction. III. The enthalpy of the products is greater than the enthalpy of the reactants.
7The reaction H₂(g) + Cl₂(g) → 2HCl(g) has a ΔH of -186 kJ mol⁻¹. The bond enthalpies of H-H and Cl-Cl are 436 kJ mol⁻¹ and 242 kJ mol⁻¹ respectively. What is the bond enthalpy of H-Cl?
8When solid potassium chloride is added to water, the temperature of the solution falls. What conclusion can be made from this observation?
9Which process is exothermic?
10Vanadium(V) oxide, V₂O₅, catalyses the conversion of sulfur dioxide to sulfur trioxide. Which statements about vanadium(V) oxide are true? I. It causes sulfur dioxide molecules to move faster. II. It decreases the activation energy of the reaction. III. It remains chemically unchanged at the end of the reaction. IV. Its mass remains unchanged at the end of the reaction.
