Which of the following has the highest value of K_p ? — Qualitative and Quantitative Analysis Chemistry Question

💡 Solution & Explanation

Step 1: The thermal decomposition of alkaline earth metal carbonates follows the equation: MCO3(s) <=> MO(s) + CO2(g). The equilibrium constant K_p for this reaction is equal to the partial pressure of CO2 (P_CO2). Step 2: The thermal stability of carbonates increases down the group as the ionic size of the cation increases and polarizing power decreases, meaning BeCO3 is the least stable and decomposes most readily. Step 3: Because BeCO3 decomposes most easily at any given temperature, it has the highest equilibrium pressure of CO2 (highest K_p), corresponding to option (a).