• # question_answer 4) Why does the solubility of alkaline earth metal hydroxides in water increase down the group?

Lattice energies of the sulphates are nearly the same. The size of sulphate ion is large and small changes in cation size do not affect the lattice energies. However, the hydration energies decrease from $B{{e}^{2+}}$ to$B{{a}^{2+}}$. Hence, solubility of sulphates decreases from top to bottom.