`BaSO_4` is insoluble in water whereas `BeSO_4` is soluble in water - explain with reasons.

Explanation

The lattice enthalpy of `BaSO_4` is much higher than its hydration enthalpy and hence it is insluble in water. On the other hand, the hydration enthalpy of `BeSO_4` is much higher than its lattice enthalpy because of loose packing of small `Be^(2+)` ion with the relatively large sulphate ion. Hence, it becomes soluble in water.