QJEEM02Ch7a72: JEE Main 2002 Chemistry - Class 11 JEEM02Ch7a72 Solution: In which of the following species the interatomic bond angle is …

Bond angle 109^o 28' means Regular Tetrahedral geometry and hybridization is sp³.

Steric Number (SN) for sp³ hybridization is 4.

In sp³ molecules can have different shapes which is decided by SN number

(1) $$$$ 4 bond pair in a molecule then angle between bonds 109^o 28^'

(2) $$$$ 3 bond pair and 1 lone pair in a molecule then angle between bonds 107^o.

(3) $$$$ 2 bond pair and 2 lone pair in a molecule then angle between bonds 104.5^o

(4) $$$$ 1 bond pair and 3 lone pair in a molecule then bond angle is undefined as there is only one bond.

(1) $$$$ In NH₃, 3 Bond pair(BP) +1 lone pair (LP) present so angle between bond 107^o.



(2) $$$$ BF$${}_4^{-}$$, 4 bond pair present so angle is 109^o 28^'.



(3) In NH$${}_4^{+}$$, 4 bond pair present so angle between bond is 109^o 28^'



(4) $$$$ BF₃ has sp² hybridization. So bond angle is 120^o.



(5) $$$$ In NH$${}_2^{-}$$, 2 bond pair and 2 lone pair present, so bond angle is 104.5^o



So, $$NH{}^{+}$$ and BF$${}_4^{-}$$ has bond angle 109^o 28^'.