Question

Which of the following sets has Lewis acid behaviour for all the components?

• A. $BH_3$
• B. $BF_3, SiF_4, PF_5$
• C. $SiF_4, PF_5$
• D. $BF_3, PF_5$

Answer 1

Answer: (B)

$BF_3, SiF_4, PF_5$

Answer 2

$BF _{3}, SiF _{4}$ and $PF _{5}$ shows lewis acid behaviour as these species readily accepts electron pair. In lewis concept, many acids do not have proton. These species are electron deficient that readily react with base by accepting its lone-pair of electron

$\underset{\text{Lewis acid (electron acceptor)}}{A^{+}} +\underset{\text{Lewis base (electr on donor)}}{B ^{\ominus}} \longrightarrow \underset{\text{Coordinate covalent bond}}{A - B}$