Question

Bf2 is soluble in water whereas the flouoride is of other alkaline earth metal are insoluble because of

Answer 1

BeF2 is soluble in water due to evolution of large hydration energy, when it is dissolved in water, which is sufficient enough to overcome the lattice energy of the Berylium Flouride, as for a compound to be soluble in water, the lattice energy of the compound must be less than the hydration energy evolved upon dissolution in water.

The solubility of a compound in water depends on the balance between lattice energy and hydration energy. Due to small size lattice energy of LiF is greater