Question 1: Define Le Chatelier's Principle in your own words.

Answer: Le Chatelier's Principle states that if a change is made to a system at equilibrium, the system will adjust itself to counteract the change and restore a new equilibrium.

Question 2: List three factors that can disturb a chemical equilibrium.

Answer: Changes in concentration, temperature, and pressure can disturb a chemical equilibrium.

Question 1: In a reaction at equilibrium, the concentration of reactant A is 0.5 mol/L and product B is 1.0 mol/L. If the concentration of A decreases to 0.3 mol/L upon adding more B, explain how Le Chatelier's Principle predicts the shift of the reaction.

Answer: According to Le Chatelier's Principle, adding more B shifts the equilibrium toward the reactants to reduce B's concentration, resulting in more A being produced.

Question 2: A reversible reaction has an equilibrium constant (Kc) of 4.0 at 25°C. If the concentration of reactants is doubled, what happens to the reaction quotient (Q)? Does the reaction shift to the products or reactants? Explain briefly.

Answer: Doubling reactant concentrations increases Q. Since Q was initially equal to Kc, Q now exceeds Kc, causing the reaction to shift toward the reactants to re-establish equilibrium.

Question 1: Describe a simple experiment to demonstrate Le Chatelier's Principle using a reaction in a closed container.

Answer: One experiment involves increasing the temperature of a reaction mixture in a sealed container and observing the shift in equilibrium, such as the color change or gas production, indicating the direction of shift.

Question 2: What safety precautions should be taken when performing experiments involving temperature changes or gases?

Answer: Wear safety goggles and gloves, conduct the experiment in a well-ventilated area, and handle chemicals carefully to prevent spills or reactions that could cause injury.

Question 1: In an industrial process, increasing the pressure caused the yield of a certain product to increase. Explain how Le Chatelier's Principle accounts for this observation.

Answer: Increasing pressure favors the side of the reaction with fewer gas molecules, shifting the equilibrium toward that side and increasing the product yield.

Question 1: Explain how temperature affects the position of equilibrium in an exothermic reaction according to Le Chatelier's Principle.

Answer: In an exothermic reaction, increasing temperature adds heat, which Le Chatelier's Principle predicts will shift the equilibrium toward the reactants to absorb the excess heat. Conversely, decreasing temperature shifts the equilibrium toward the products.

Question 2: A reaction has an equilibrium constant (Kc) of 0.5 at 300K. If the temperature is increased, predict how the value of Kc might change and justify your answer.

Answer: For an exothermic reaction, increasing temperature typically decreases Kc because the equilibrium shifts toward reactants to counteract the temperature increase. For an endothermic reaction, Kc would increase.

Question 1: Explain how Le Chatelier's Principle is used in the Haber process for ammonia production.

Answer: In the Haber process, high pressure and moderate temperature are used to shift the equilibrium toward ammonia production. Increasing pressure favors the formation of ammonia, and temperature adjustments balance the rate of reaction with yield.