Identify the correct order of solubility in aqueous medium:
The correct option is DBeSO4>MgSO4>CaSO4>BaSO4 As we move down the group, size increases (Be<Mg<Ca<Ba). Solubility depends on the hydration energy and the latiice energy. Generally, as the difference in size of the cation and the anion increases, hydration energy dominates and solubility increases. Whereas, as the difference decreases, lattice energy dominates and solubility decreases. So, here we have SO2−4 anion whose size is large and as we move down the group, size difference decreases and hence solubility decreases.