Anhydrous `AlCl_(3)` is covalent. From the date given below, predict whether it would remain covalent or become ionic in aqueous solution. (Ionisation energy for `Al` is `1537 kJ mol^(-1)`)
`Delta_("hydration") for Al^(3+) = - 4665 kJ mol^(-1)`
`Delta_("hydration") for Cl^(Ө) = - 381 kJ mol^-1`.

Explanation

Total energy evolved due to hydration = -4665 - 36-381) = -5808 kJ/mole. As this released energy is greater than ionization energy (5137 kJ/mole) of Al, `AlCl_3` can be ionic in aqueous solution.