Reversible And Irreversible Reaction MCQs

Here are 40 MCQs on Reversible and Irreversible Reactions, numbered from 11 to 50:

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11. In a reversible reaction:

• A) Products cannot convert back to reactants
• B) Reactants convert into products irreversibly
• C) Both forward and reverse reactions can occur
• D) Only one direction reaction is possible
• Answer: C

12. An example of a reversible reaction is:

• A) Combustion of methane
• B) Neutralization of acid and base
• C) Formation of ammonia in the Haber process
• D) Dissolution of sugar in water
• Answer: C

13. In an irreversible reaction, the reactants are:

• A) Completely used up to form products
• B) Partially converted into products
• C) Constantly recycled
• D) In dynamic equilibrium with products
• Answer: A

14. Which of the following is an example of an irreversible reaction?

• A) Evaporation of water
• B) Rusting of iron
• C) Formation of carbonic acid from CO₂ and H₂O
• D) Formation of hydrogen gas from water electrolysis
• Answer: B

15. In a closed system, reversible reactions:

• A) Never reach equilibrium
• B) Eventually reach dynamic equilibrium
• C) Only proceed in one direction
• D) Stop when products are formed
• Answer: B

16. Which of the following best describes a dynamic equilibrium?

• A) Reactants stop converting to products
• B) Forward and reverse reactions continue at equal rates
• C) The reaction only proceeds in one direction
• D) There is no net change in concentration of reactants
• Answer: B

17. When the conditions of a reversible reaction are altered, the equilibrium will:

• A) Remain unaffected
• B) Shift to counteract the change
• C) Stop completely
• D) Accelerate in both directions
• Answer: B

18. Which factor does NOT affect the position of equilibrium in a reversible reaction?

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

19. A catalyst in a reversible reaction:

• A) Increases the yield of products
• B) Shifts equilibrium to the right
• C) Equally accelerates both forward and reverse reactions
• D) Has no effect on reaction rate
• Answer: C

20. In an irreversible reaction, the reaction rate:

• A) Decreases with time as reactants are used up
• B) Increases continuously
• C) Remains constant
• D) Is unaffected by reactant concentration
• Answer: A