31. Water in equilibrium expressions is: A) Included B) Excluded if pure C) Always included D) Never included Answer: B
32. Effect of catalyst on K: A) Increases B) Decreases C) No effect D) Doubles Answer: C
33. For gaseous reactions, pressure change affects equilibrium only if: A) Δn ≠ 0 B) Δn = 0 C) Temperature constant D) Catalyst present Answer: A
34. Reaction at equilibrium has: A) No reaction B) Maximum rate C) Equal rates D) Zero energy Answer: C
35. Units of Kc for reaction A ⇌ B: A) mol/L B) Unitless C) mol²/L² D) Depends Answer: B
36. Increasing concentration of product shifts equilibrium: A) Right B) Left C) No change D) Stops Answer: B
37. Equilibrium constant is independent of: A) Temperature B) Initial concentration C) Reaction D) Phase Answer: B
38. Kc expression for aA + bB ⇌ cC is: A) [A][B]/[C] B) [C]/[A][B] C) [C]^c / [A]^a[B]^b D) [A]^a[B]^b / [C]^c Answer: C
39. Increasing pressure favors: A) Side with more gas B) Side with less gas C) No change D) Solid formation Answer: B
40. Equilibrium shifts right when: A) Reactants increase B) Products increase C) Pressure decreases D) Catalyst added Answer: A