• # question_answer71)   Explain why the following compounds act as Lewis acids? (a) $BC{{l}_{3}}$                             (b) $AlC{{l}_{3}}$

$\mathbf{BC}{{\mathbf{l}}_{\mathbf{3}}}$is an electron deficient compound as the boron atom acquires six electrons in its outermost shell. It can accept a pair of electrons from a suitable donor to attain an octet configuration. Thus, $BC{{l}_{3}}$ acts as a Lewis acid. $AlC{{l}_{3}}$is also an electron deficient compound and accepts alone pair from a donor and acts as a Lewis acid.