Question
Which one of the following molecular hydrides acts as a Lewis acid?
-
NH3
-
H2O
-
B2H6
-
CH4
Solution
C.
B2H6
Electron deficient molecules behave as Lewis acid.
Among the given molecules, only diborane is electron deficient, ie, does not have a complete octet. Thus, it acts as a Lewis acid.
NH3 and H2O being electron rich molecules behave as Lewis base.