Solubility depends on the lattice energy of the solid and the hydration energy of the ions. Some lattice values for Group - II compounds are much lighter than the values for Group - I compounds, because of the effect of the increased charge on the ions in the Boron - Lande equation. Taking any one particular negative ion the lattice energy decreases as the size of the metal increases. The hydration energy also decreases as the metal ions become larger. For a substance to dissolve, the hydration energy must exceed thelattice energy The correct order of solubility is

Solubility depends on the lattice energy of the solid and the hydratio

1.	Solubility depends on the lattice energy of the solid and the hydration energy of the ions. Some lattice values for Group - II compounds are much lighter than the values for Group - I compounds, because of the effect of the increased charge on the ions in the Boron - Lande equation. Taking any one particular negative ion the lattice energy decreases as the size of the metal increases. The hydration energy also decreases as the metal ions become larger. For a substance to dissolve, the hydration energy must exceed thelattice energy The correct order of solubility is
Answer» `BeF_(2)ltCaF_(2)gtSrF_(2)gtBaF_(2)` `BeF_(2)gtCaF_(2)ltSrF_(2)ltBaF_(2)` `CaF_(2)ltSrF_(2)ltBaF_(2)ltBeF_(2)` `CaF_(2)gtSrF_(2)gtBaF_(2)gtBeF_(2)`` SOLUTION :The correct order of solublity is `CaF_(2) lt SrF_(2) lt BaF_(2) lt BeF_(2)` The high VALUE of solubility of `BeF_(2)` is due to high hydration energy of `Be^(+2)` ION