Anhydrous Magnesium chloride () cannot be prepared by simply heating its hydrated salt, , in an open — s Block Elements Chemistry Question

💡 Solution & Explanation

Due to the high polarizing power and high hydration energy of $Mg^{2+}$, the coordinated water molecules attack the chloride ions upon strong heating. This causes hydrolysis rather than simple dehydration: $MgCl_2 \cdot 6H_2O \xrightarrow{\Delta} MgO + 2HCl \uparrow + 5H_2O \uparrow$.