Question 1: Define dynamic equilibrium in the context of reversible chemical reactions.

Answer: Dynamic equilibrium occurs when the forward and reverse reactions in a reversible reaction occur at the same rate, resulting in constant concentrations of reactants and products.

Question 2: Explain why the concentrations of reactants and products remain constant at equilibrium, despite ongoing reactions.

Answer: Because the rates of the forward and reverse reactions are equal, the amounts of reactants and products stay unchanged over time.

Question 3: What effect does increasing the temperature have on the position of equilibrium in an endothermic reaction? Briefly justify your answer.

Answer: Increasing temperature shifts the equilibrium position towards the endothermic reactants, as the system responds to absorb the added heat according to Le Châtelier's principle.

Question 4: Identify the variable that remains constant in a system at equilibrium.

Answer: The temperature and pressure (if applicable) remain constant at equilibrium.

Question 5: Describe a practical scenario where understanding dynamic equilibrium is important in industry.

Answer: In the Haber process for making ammonia, controlling temperature and pressure to optimise equilibrium position is crucial for efficient production. Managing equilibrium shifts ensures maximum yield of ammonia while maintaining safety and cost-effectiveness.

Question 6: In an experiment, the concentration of reactant A decreases while the concentration of product B increases until a certain point. What does this indicate about the reaction system?

Answer: It indicates that the forward reaction is predominating until the system reaches equilibrium, where the rates of the forward and reverse reactions are equal.

Question 7: Calculate the change in concentration if, in a reaction at equilibrium, the forward rate is 0.05 mol/L/s and the reverse rate is 0.05 mol/L/s. Assume the initial concentrations of reactants and products are 1.0 mol/L.

Answer: Since the rates are equal, the concentrations remain unchanged at 1.0 mol/L for both reactants and products, indicating the system is at equilibrium.

Question 8: Identify two factors that can disturb a system at equilibrium and explain how each factor affects the system.

Answer: Changes in temperature can shift the equilibrium position to favour either reactants or products. Changes in pressure, especially in gaseous systems, can also shift the equilibrium by favouring the side with fewer or more moles of gas.

Question 9: What safety precautions should be considered when working with systems at equilibrium in industrial settings?

Answer: Proper ventilation, temperature control, and protective equipment are essential to handle potentially hazardous gases and reactions, ensuring safety and preventing accidents.