Anhydrous `Al Cl_(3)` is covalent . From the data given below
Lattice Energy `=5137KJ//mol`
`DeltaH` hydrogen for `Al^(3+)=-4665KJ//mol`
`DeltaH` hydration for `Cl^(-)=-381KJ//mol`
Identify the correct statement.

Options

A. It will remain covalent in aqueous solution
B. The solution will consist of `Al^(3+)` & `Cl^(-)`
C. The solution will consist of hydrated `Al^(3+)` & `Cl^(-)`
D. None of these

Answer

C

Explanation

`implies DeltaH_("solution")= -4665-3 xx 381+5137 lt 0`
Hence `AlCl_3` will dissolve and solution consists of hydrated `Al^(3+)` and `Cl^-` ions. In other words higher hydration energy compensates the higher ionisation energy . As a result , it will exist as hydrated `Al^(3+)` and hydrated `Cl^-` in aqueous solution.