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

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

Question 2: Explain why increasing the temperature of an exothermic reaction shifts the equilibrium position.

Answer: Increasing temperature adds heat to the system, and according to Le Chatelier's Principle, the equilibrium shifts in the direction that absorbs heat, which for an exothermic reaction is the reactant side, to counteract the change.

Question 3: In an experiment, adding more reactant to a closed system causes the product concentration to increase. What does this indicate about the system's response?

Answer: It indicates that the system shifts toward producing more product to counteract the increase in reactant, moving the equilibrium position forward.

Question 4: Calculate the change in concentration (in mol/L) if 0.5 mol of a gas is added to a 2.0 L container.

Answer: Change in concentration = amount added / volume = 0.5 mol / 2.0 L = 0.25 mol/L.

Question 5: Identify the variable that would most directly cause a shift in equilibrium if increased: pressure, temperature, concentration, or catalyst.

Answer: Pressure

Question 6: Fill in the blank: When the concentration of products is increased in a system at equilibrium, the system will shift ______ the products.

Answer: away from

Question 1: Describe an experiment to demonstrate the effect of changing pressure on the equilibrium of a reaction involving gases.

Answer: One experiment involves placing a gaseous reaction mixture in a sealed container and varying the pressure by adding or removing an inert gas or changing the volume. Observations are made on how the concentrations of reactants and products shift with pressure changes, demonstrating Le Chatelier's response.

Question 2: Identify two safety precautions that should be taken when heating reactions to observe shifts in equilibrium.

Answer: Use heat-resistant gloves and safety goggles to protect against splashes or glass breakage; ensure proper ventilation to avoid inhaling fumes.

Question 3: A manufacturer increases the pressure in a reactor where ammonia synthesis occurs (N₂ + 3H₂ ⇌ 2NH₃). Explain how this change affects the production of ammonia.

Answer: Increasing pressure shifts the equilibrium toward the side with fewer gas molecules—in this case, toward ammonia—thus increasing its production.

Question 4: Describe how changing the temperature can be used to optimize the yield of a chemical reaction at equilibrium.

Answer: Adjusting temperature can shift the equilibrium position to favor either reactants or products depending on the reaction's enthalpy change. For an exothermic reaction, lowering temperature favors product formation, while for an endothermic reaction, increasing temperature is beneficial. This control allows for maximizing yield based on the reaction's thermodynamics.

Question 1: A chemical plant adjusts the pressure of a reactor to increase the production of sulfuric acid (H₂SO₄). How does Le Chatelier's Principle explain this adjustment?

Answer: Increasing pressure favors the side of the reaction with fewer gas molecules. Since the production of sulfuric acid involves fewer moles of gas, increasing pressure shifts the equilibrium toward more H₂SO₄ formation.

Question 2: In the context of industrial ammonia synthesis, why is temperature carefully controlled rather than just increased or decreased arbitrarily?

Answer: Because the reaction is exothermic and shifting temperature affects both the yield and rate, careful control ensures optimal ammonia production without excessive energy consumption or loss of efficiency, following Le Chatelier's response.