Question 1: Define dynamic equilibrium in the context of a chemical reaction.

Answer: Dynamic equilibrium occurs when the forward and reverse reactions in a chemical system happen at the same rate, resulting in no net change in the concentrations of reactants and products.

Question 2: Explain how the principle of Le Châtelier's principle relates to dynamic equilibrium.

Answer: Le Châtelier's principle states that if a system at equilibrium is subjected to a change in concentration, temperature, or pressure, the system will adjust to partially counteract the change and restore a new equilibrium.

Question 1: A reaction at equilibrium has a concentration of 0.5 M of reactant A and 0.2 M of product B. The equilibrium constant (Kc) for the reaction A ⇌ B is 0.4. Calculate the concentrations of A and B if the total concentration remains constant and the reaction shifts to reach equilibrium.

Answer: Using equilibrium expression Kc = [B]/[A], rearranged to find [A] and [B], with initial conditions and shifts considered, the concentrations are approximately [A] = 0.33 M and [B] = 0.13 M.

Question 2: If the forward reaction rate is 0.3 M/s and the reverse reaction rate is 0.3 M/s at equilibrium, what is the rate of the reaction?

Answer: The rate of the reaction is 0.3 M/s, since at equilibrium, the forward and reverse reaction rates are equal.

Question 1: Describe a simple laboratory experiment to demonstrate dynamic equilibrium involving a reversible reaction or process.

Answer: A common experiment involves the reaction of iodine with bleach, observing the color change as the system reaches equilibrium between iodine and iodide ions in solution.

Question 2: Identify three variables that can affect the position of equilibrium in an environmental system, and state a safety precaution for each.

Answer: Variables include temperature (safety: wear heat-resistant gloves), concentration of pollutants (safety: avoid inhalation of fumes), and pressure (safety: use proper pressure-resistant containers).

Question 1: In an environmental system, the decomposition of sulfur dioxide (SO2) in the atmosphere reaches a dynamic equilibrium with sulfur trioxide (SO3). If increased sunlight causes the reaction to shift forward, explain how this affects air quality and what this indicates about the reaction's sensitivity to environmental conditions.

Answer: The forward shift increases SO3 formation, which can lead to acid rain and pollution. This indicates that the reaction is sensitive to environmental factors like sunlight, affecting atmospheric chemistry.

Question 2: A factory uses a reversible process to produce a chemical used in water purification. The process reaches equilibrium at a certain concentration. If the factory increases the input of reactants, describe the expected change in product concentration and why.

Answer: Increasing reactant input shifts the equilibrium toward the formation of more product, increasing its concentration until a new equilibrium is established, according to Le Châtelier's principle.