For the reaction: CaCO₃(s) ⇌ CaO(s) + CO₂(g), K_p is — Chemical Equilibrium Chemistry Question

💡 Solution & Explanation

The equilibrium constant K_p for a heterogeneous equilibrium only includes the partial pressures of the gaseous species. Solids are omitted (activity = 1). Therefore, K_p = P_CO₂. Therefore, correct answer is A.