GKFix MCQ Question

In the reaction CaCO3(s) ⇌ CaO(s) + CO2(g), what is the correct expression for Kp?

• A. Kp = pCaCO₃ × pCO₂ / pCaO
• B. Kp = pCaO / pCaCO₃
• C. Kp = pCO₂
• D. Kp = pCaO × pCO₂ / pCaCO₃