The sulphates of alkaline earth metals like and are insoluble in water primarily because: — Chemical Bonding Chemistry Question

💡 Solution & Explanation

Solubility of ionic compounds requires hydration energy to exceed lattice energy. For large cations like $Ba^{2+}$ and $Sr^{2+}$ paired with large anions like $SO_4^{2-}$, the lattice energy decreases less rapidly than the hydration energy down the group, making them insoluble.