Which of the following is least likely to behave as Lewis base?
- H2O
- NH3
- BF3
- OH-
Answer
(3) BF3
Solution
A Lewis base donates an electron pair.
H2O (2 lone pairs on O), NH3 (1 lone pair on N) and OH- (3 lone pairs on O) can donate electron pairs Lewis bases.
As per NCERT, BF3 is electron deficient (only 6 electrons around B), so it accepts an electron pair Lewis acid.
Answer: (3)