Which of the following is not a Lewis acid ?

Options

A. `AICI_(3).6H_(2)O`
B. `AICI_(3)`
C. `SnCI_(4)`
D. `FeCI_(3)`

Answer

A

Explanation

A Lewis acid is characterized by its ability to accept at least one lone pair using an empty orbital of right energy. `AlCl_(3), SnCl_(4)`, and `FeCl_(3)` act as Lewis acids because of the ability of their central atoms to accept lone pairs in their empty orbitals. `AlCl_(3).6H_(2)O` or `[Al(H_(2)O)_(6)]Cl_(3)` cannot act as a Lewis acid because the central ion `Al^(3+)` is no longer in a position to accept the lone pair as its coordination number is fulfilled.