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

`AlCl_(3) (S) + aqto AlCl_(3) (aq)^(3+) (aq) + 3Cl^(-) (aq)`
Total energy released on hydration of 1 mole of `Al^(3+)` ions and 3 moles of `Cl^(-)` ions
`= 4665+3xx381 KJ = 5808 mol ^(-1)`
Energy required for ionization = 5137 kJ `mol^(-1)`
As energy released is greater than the energ required the compound will ionize in aqueous
solution .