Out of anhydrous `AlC_3` and hydrated `AlCl_3` , which one is more soluble in diethyl ether and why?

Explanation

Anhydrous `AlCl_3` is an electron deficient compound (Lewis acid) while hydrated `AlCl_ 3` i.e., `AlCl_3 · 6H_2O`, is not because `H_2O` has already donated a pair of electron to Al.
Therefore, the O -atom of diethyl ether donates a pair of electrons to the Al -atom of anhydrous `AlCl_3` forming a coordinate bond. For this reason, anhydrous `AlCl_3` is more soluble in diethyl ether.