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

LiF is almost insoluble in water [0.27/l100g ${{H}_{2}}$O} due to its high lattice energy. Due to high hydration energy of Li+ ion LiCl is soluble in water. LiCl is also soluble in acetone because of its predominantly covalent nature. With the increasing size of the anion covalent character increases.