Which direction will the following reaction (in a 10.0 L flask) proceed if a catalyst is added to the system? 
CaCO₃ (s)  ⇌ CaO (s) + CO₂ (g)            K_p = 3.2 x 10^-28

• A. To the right.
• B. To the left.
• C. The equilibrium position will not change but the rate will increase.
• D. The equilibrium position will not change but the concentrations of everything will increase.

Answer: (C)

Verified step by step guidance

1. Identify the role of a catalyst in a chemical reaction. A catalyst speeds up the rate of a reaction by lowering the activation energy but does not affect the equilibrium position of the reaction.
2. Examine the given reaction: CaCO3 (s) ⇌ CaO (s) + CO2 (g). Note that the equilibrium constant, Kp, is provided as 3.2 x 10^-28, indicating the position of equilibrium is heavily towards the reactants under standard conditions.
3. Understand that the equilibrium constant (Kp) is a measure of the ratio of the concentrations of products to reactants at equilibrium. A very small Kp value suggests that at equilibrium, the concentration of products is much lower than that of the reactants.
4. Consider the effect of adding a catalyst. Since a catalyst does not change the equilibrium constant or the position of equilibrium, the direction of the reaction will not be affected by the addition of a catalyst.
5. Conclude that while the rate of reaching equilibrium will increase due to the catalyst, the equilibrium position itself remains unchanged. Therefore, the correct answer is that the equilibrium position will not change, but the rate of the reaction will increase.