Question Detail
Question
Two moles of compound P were placed in a vessel. The compound P was partly decomposed by heating. A dynamic equilibrium between chemicals P, Q and R was established. At equilibrium, x mol of R were present and the total number of moles present was (2 + x). What is the equation for this equilibrium?
Correct Answer
Option B is the correct answer.
Detailed Explanation
Initial moles P = 2. Let the reaction be 2P ⇌ 2Q + R. If x mol R is formed, then 2x mol P is consumed, and 2x mol Q is formed. At equilibrium: P = 2-2x, Q = 2x, R = x. Total moles = (2-2x)+2x+x = 2+x. This matches the given total.
Hint
Use the total moles at equilibrium to determine the change in moles and thus the stoichiometry.