Question

Consider the exothermic chemical reaction O₂(𝑔)+2H₂(𝑔) ⇌ 2H₂O(𝑔) at equilibrium in a closed container. The correct statement(s) is/are

• A. At equilibrium, introduction of catalyst increases product formation
• B. Equilibrium constant decreases with increase in temperature.
• C. The equilibrium constant 𝐾_𝑃 increases with pressure.
• D. Decrease in volume of reaction vessel increases product formation.

Answer 1

The Correct Option is B, D

• (A) A catalyst only affects the rate of reaction, not the equilibrium position. Therefore, the introduction of a catalyst does not increase product formation at equilibrium.
• (B) For an exothermic reaction, increasing the temperature shifts the equilibrium toward the reactants (Le Chatelier’s Principle). Thus, the equilibrium constant decreases with an increase in temperature.
• (C) The equilibrium constant K_p is not directly affected by pressure for reactions involving gases unless there is a change in the number of moles of gas. Since this reaction has no change in the number of moles of gas, K_p remains unaffected by pressure.
• (D) According to Le Chatelier’s Principle, reducing the volume of a reaction vessel increases the pressure and shifts the equilibrium toward the side with fewer moles of gas. In this case, the product side (2 moles of H₂O) has fewer moles of gas than the reactant side (3 moles of gas), so decreasing the volume increases product formation.

Thus, the correct answers are (B) and (D)