Solubility of alkaline earth metal sulphates decreases down the group 2 because

Options

A. they become more ionic
B. lattice energy of sulphates does not vary significantly
C. hydration energy decrease rapidly from `Be^(2+)` to `Ba^(2+)`
D. lattice energy plays more predominant role than hydration energy.

Answer

C

Explanation

Due to very large size of sulphate ions, the magnitude of lattice energy of alkaline earth metal sulphates remains almost constant. Thus, their solubility is governed by only hydration energy decreases fromo `Be^(2+)` to `Ba^(2+)`.