Reversible And Irreversible Reaction MCQs

31. Irreversible reactions are common in:

• A) Organic synthesis
• B) Biological metabolism
• C) Decomposition of calcium carbonate
• D) All of the above
• Answer: D

32. A reversible reaction will shift to counteract a disturbance, according to:

• A) Boyle’s Law
• B) Le Chatelier’s Principle
• C) Law of Mass Action
• D) Dalton’s Law
• Answer: B

33. An irreversible reaction cannot:

• A) Go to completion
• B) Reach dynamic equilibrium
• C) Be carried out in closed systems
• D) Have high reactant concentrations
• Answer: B

34. Which reaction type typically reaches equilibrium in a closed system?

• A) Combustion
• B) Dissolution
• C) Irreversible decomposition
• D) Reversible synthesis
• Answer: D

35. For a reaction to be reversible, it must occur in a:

• A) Closed system
• B) Open system
• C) Large container
• D) Sealed tube only
• Answer: A

36. The rate of an irreversible reaction:

• A) Is constant throughout
• B) Decreases as reactants are consumed
• C) Is equal to the reverse reaction rate
• D) Depends only on catalyst presence
• Answer: B

37. In reversible reactions, if temperature is increased, the equilibrium shifts:

• A) Towards the exothermic direction
• B) Towards the endothermic direction
• C) Towards reactants only
• D) Towards products only
• Answer: B

38. Which reaction typically does not reach equilibrium?

• A) Reaction between sodium and water
• B) Decomposition of hydrogen peroxide
• C) Formation of nitrogen dioxide from nitric oxide
• D) Synthesis of water from hydrogen and oxygen
• Answer: A

39. For a reversible reaction in equilibrium, if pressure increases, the equilibrium will shift:

• A) Towards the side with fewer gas molecules
• B) Towards the side with more gas molecules
• C) Toward the reactants
• D) Be unaffected
• Answer: A

40. Le Chatelier’s Principle is applied to predict changes in:

• A) Irreversible reactions
• B) Chemical equilibrium
• C) Activation energy
• D) Product yield only
• Answer: B