Chemistry - Complete s-block Question with Solution | TestHub

Key Idea Hydration energy varies inversely with size and in sulphates of alkaline earth metals lattice energy remains almost constant. The order of size of alkaline earth metals is $${\mathrm{Be}}^{2+}<{\mathrm{Ca}}^{2+}<{\mathrm{Sr}}^{2+}<{\mathrm{Ba}}^{2+}$$ Thus, the order of hydration energy is $${\mathrm{Be}}^{2+}>{\mathrm{Ca}}^{2+}>{\mathrm{Sr}}^{2+}>{\mathrm{Ba}}^{2+}$$ Hence, ${\mathrm{BeSO}}_4$ has the hydration enthalpy higher than the lattice enthalpy.