Question

Is $AlC{l_3}$ a lewis base?

Answer 1

Hint : Lewis acids and bases are electron-pair acceptors and electron-pair donors, respectively, according to the Lewis theory of acid-base reactions. Lewis acids are chemical compounds with empty orbitals that can accept electron pairs from Lewis bases. Lewis bases are atomic or molecular chemical species with a highly localised HOMO (Highest Occupied Molecular Orbital).

Complete Step By Step Answer:
Since the aluminium atom has an open valence shell, aluminium chloride ( $AlC{l_3}$ ) is a Lewis acid. Lewis acid (e.g., $B{F_3}$ , $Al{F_3}$ ) is an atom, ion, or molecule with an incomplete electron octet (e.g., $SiB{r_4}$ , $Si{F_4}$ ). Lewis bases donate a pair of electrons. A Lewis base is an atom, ion, or molecule with a single electron pair.
Aluminium chloride is a chemical compound with the formula $AlC{l_3}$ . In comparison to the white, pure compound, it takes on a yellow hue when contaminated with iron chloride. It's used as a Lewis base in a variety of chemical reactions, with anhydrous aluminium trichloride being the most common Lewis acid.
Depending on the temperature and state, $AlC{l_3}$ takes on one of three structures (solid, liquid, gas). Solid $AlC{l_3}$ is layered cubic close packed layers in a sheet-like structure. When melted, aluminium trichloride exists as the dimer $A{l_2}C{l_6}$ , which contains tetracoordinate aluminium.

Note :
In the Friedel-Crafts alkylation process, Lewis acids play an important role as a catalyst in the Friedel-Crafts reaction – $AlC{l_3}$ accepts a lone pair of electrons from the chloride ion, resulting in the formation of $AlC{l_4}$ –. This also results in the formation of the highly electrophilic carbonium ion, which functions as a powerful Lewis acid. The following is an example of a chemical reaction.
$RCl + AlC{l_3} \to {R^ + } + AlC{l_4}^ -$ Lewis acids are commonly used in organic chemistry to promote cationic or pseudo-cationic chemical reactions.