21. In an exothermic reaction at equilibrium, increasing temperature will shift the equilibrium:

• A) Toward the products
• B) Toward the reactants
• C) Equally toward both sides
• D) Has no effect
• Answer: B

22. What happens to the value of Kc if the temperature changes?

• A) Increases only
• B) Decreases only
• C) Remains constant
• D) Changes depending on reaction type
• Answer: D

23. Which of the following would cause a change in the equilibrium constant Kc?

• A) Changing the pressure
• B) Adding a catalyst
• C) Changing the temperature
• D) Changing concentration of reactants
• Answer: C

24. If ( Q = K ), the reaction is:

• A) Shifting towards reactants
• B) Shifting towards products
• C) At equilibrium
• D) Has no reaction
• Answer: C

25. Le Chatelier’s Principle can predict changes in equilibrium based on:

• A) Temperature only
• B) Pressure and concentration only
• C) All changes in external conditions
• D) Volume only
• Answer: C

26. For the reaction ( 2SO_2 + O_2 \rightleftharpoons 2SO_3 ), decreasing the pressure will:

• A) Shift equilibrium to the right
• B) Shift equilibrium to the left
• C) Have no effect
• D) Increase concentration of ( SO_3 )
• Answer: B

27. The reaction quotient (Q) is used to:

• A) Determine the direction of the reaction
• B) Measure reaction rate
• C) Predict temperature change
• D) Calculate activation energy
• Answer: A

28. If the Kc value for a reaction is 10⁻⁴, it implies:

• A) Reactants are favored
• B) Products are favored
• C) Neither are favored
• D) The reaction is complete
• Answer: A

29. Increasing the concentration of a product will cause equilibrium to:

• A) Shift to the left
• B) Shift to the right
• C) Stay constant
• D) Form more product
• Answer: A

30. Which factor does NOT affect the position of equilibrium?

• A) Temperature
• B) Pressure
• C) Catalyst
• D) Concentration
• Answer: C