Ques. 1AIPMT 2010 (Prelims)
Which one of the following molecular hydrides acts as a Lewis acid?
- NH3
- H2O
- B2H6
- CH4
Answer
(3) B2H6
Solution
As per NCERT, molecular hydrides are classified as electron-deficient, electron-precise and electron-rich hydrides.
B2H6 is electron-deficient (too few electrons for normal covalent bonds) acts as a Lewis acid (electron acceptor).
CH4 is electron-precise (neither acid nor base); NH3 and H2O are electron-rich (lone pairs) Lewis bases.
Answer: (3)