Reversible And Irreversible Reaction MCQs

21. A reaction that goes to completion is classified as:

• A) Reversible
• B) Irreversible
• C) Spontaneous
• D) Endothermic
• Answer: B

22. The state in which the forward and reverse reactions are equal is called:

• A) Static equilibrium
• B) Dynamic equilibrium
• C) Irreversible reaction
• D) Completion
• Answer: B

23. Which of the following reactions is typically irreversible?

• A) Decomposition of water
• B) Photosynthesis in plants
• C) Dissociation of acetic acid in water
• D) Formation of carbon dioxide from carbon and oxygen
• Answer: D

24. At dynamic equilibrium:

• A) All reactants are converted to products
• B) Concentrations of reactants and products remain constant
• C) Reaction rates of forward and reverse reactions are zero
• D) Reactants are replenished constantly
• Answer: B

25. Which process is reversible?

• A) Burning of paper
• B) Freezing of water
• C) Mixing of sand and salt
• D) Formation of rust
• Answer: B

26. Reversible reactions are often indicated by:

• A) A single-headed arrow (→)
• B) A double-headed arrow (⇌)
• C) A half-arrow (⇀)
• D) No arrow at all
• Answer: B

27. If a product of a reversible reaction is continuously removed, the equilibrium will:

• A) Shift to produce more products
• B) Shift to produce more reactants
• C) Remain constant
• D) Stop entirely
• Answer: A

28. In an open system, a reversible reaction:

• A) Never reaches equilibrium
• B) Reaches equilibrium quickly
• C) Proceeds irreversibly
• D) Is unaffected by surroundings
• Answer: A

29. The process of dissociation of molecules into ions in a solution is typically:

• A) Reversible
• B) Irreversible
• C) Exothermic only
• D) Endothermic only
• Answer: A

30. An example of a reversible physical change is:

• A) Rusting of iron
• B) Melting of ice
• C) Combustion of wood
• D) Decomposition of potassium chlorate
• Answer: B