One mole each of A and B and 3 moles each of C and D are placed in 1 L flask. If equilibrium constan — Chemical Equilibrium Chemistry Question

💡 Solution & Explanation

Initial Q = (3 × 3) / (1 × 1) = 9. Since Q > K_c (2.25), reaction shifts backward. Let x moles of C and D react: [A] = 1+x, [B] = 1+x, [C] = 3-x, [D] = 3-x. K_c = (3-x)² / (1+x)² = 2.25. Taking square roots: (3-x) / (1+x) = 1.5 => 3 - x = 1.5 + 1.5x => 2.5x = 1.5 => x = 0.6. Eq [A] = 1.6 M, eq [C] = 2.4 M. Ratio [A]:[C] = 1.6 : 2.4 = 2:3. Therefore, correct answer is A.