The solubility of alkaline earth metal sulphates in water decreases in the order . This trend is pri — s Block Elements Chemistry Question

💡 Solution & Explanation

For alkaline earth metal sulphates, the lattice energy remains nearly constant down the group because the large sulphate anion dominates the crystal packing. However, the hydration enthalpy of the metal cations drops drastically as the size increases from $Be^{2+}$ to $Ba^{2+}$. This sharp drop in hydration enthalpy is the primary reason for the rapid decrease in solubility.