Why is LiF almost insoluble in water whereas LiCl soluble not only in water but also in acetone?

Explanation

The lattice enthalpy of ionic LiF (formed by small `Li^(+)` ion and `F^(-)` ion) is higher than its hydration enthalpy. On the other hand, the lattice enthalpy of LiCl containing small `Li^(+)` ion and large `Cl^(-)` ion is considerably lower than its hydration enthalpy. Thus, LiF is almost insoluble in water while LiCl is soluble. Furthermore, `Li^(+)` ion can polarise bigger `Cl^(-)` ion more easily than smaller `F^(-)` ion. As a result, LiCl has more covalent character than LiF and so, it is also soluble in the organic solvent acetone.