M.P. of BeCl2 is less than that of MgCl2, but reverse is true for their thermal stability. — s Block Elements Chemistry Question

💡 Solution & Explanation

Step 1: Analyze the thermal decomposition of the options. Li2CO3 decomposes to Li2O and CO2; LiOH decomposes to Li2O and H2O; NaOH is highly stable and does not decompose. Step 2: Due to the exceptionally small size and high polarizing power of the lithium cation, lithium nitrate (LiNO3) decomposes completely upon heating, behaving differently than other alkali metal nitrates. Step 3: The decomposition reaction is: 4LiNO3 -> 2Li2O + 4NO2 + O2. This reaction liberates oxygen gas (O2), matching option (c).