GKFix MCQ Question

What is the correct expression for Kp for the reaction N₂O₄(g) ⇌ 2NO₂(g)?

• A. Kp = p_N₂O₄ / (p_NO₂)²
• B. Kp = p_NO₂ / p_N₂O₄
• C. Kp = (p_NO₂)² / p_N₂O₄
• D. Kp = p_NO₂ + p_N₂O₄