Question

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

Answer 1

The lattice energy of LiF is very high due to small size of $L{i}^{+}$ ions and $F^{-}$ ions. The hydration energy of LiF is lower than lattice energy. In case of LiCl, the hydration energy is higher than the lattice energy. Hence, LiCl is water soluble. Due to higher polarization, LiCl has some covalent character. Hence, it is soluble in non polar solvents such as acetone.