Equilibrium State MCQs

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

• A) To the right
• B) To the left
• C) Equally in both directions
• D) Not at all
• Answer: A

22. In the reaction ( N_2(g) + 3H_2(g) \rightleftharpoons 2NH_3(g) ), if pressure is increased, the equilibrium will shift:

• A) To the right
• B) To the left
• C) No shift
• D) It depends on the temperature
• Answer: A

23. Adding a catalyst to a reaction at equilibrium will:

• A) Shift the equilibrium to the right
• B) Shift the equilibrium to the left
• C) Have no effect on equilibrium position
• D) Increase the equilibrium constant
• Answer: C

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

• A) Determine equilibrium constant
• B) Compare with K to predict shifts
• C) Determine concentration of products
• D) Set reaction speed
• Answer: B

25. If ( Q > K ), the reaction will:

• A) Shift left
• B) Shift right
• C) Be at equilibrium
• D) Stop completely
• Answer: A

26. For the reaction ( H_2 + I_2 \rightleftharpoons 2HI ), what is the equilibrium expression (Kc)?

• A) ( K_c = \frac{[H_2][I_2]}{[HI]^2} )
• B) ( K_c = \frac{[HI]^2}{[H_2][I_2]} )
• C) ( K_c = [H_2][I_2] \times [HI]^2 )
• D) None of these
• Answer: B

27. Which reaction would have its equilibrium constant (K) expressed in terms of concentration only?

• A) Homogeneous reaction
• B) Heterogeneous reaction
• C) Ionic reaction
• D) Aqueous reaction
• Answer: A

28. In a chemical equilibrium, the amount of reactants and products:

• A) Remain constant
• B) Become equal
• C) Continuously increase
• D) Continuously decrease
• Answer: A

29. In the expression for the equilibrium constant ( K_c = \frac{[C][D]}{[A][B]} ), the concentrations represent:

• A) Initial concentrations
• B) Equilibrium concentrations
• C) Concentrations of pure solids
• D) Concentrations of pure liquids
• Answer: B

30. For the reaction ( 2SO_2 + O_2 \rightleftharpoons 2SO_3 ), increasing the amount of ( SO_2 ) will:

• A) Shift equilibrium to the right
• B) Shift equilibrium to the left
• C) Increase equilibrium constant
• D) No effect
• Answer: A