Identify the molecule (X) with maximum number of lone pairs of electrons (obtained using Lewis dot structure) among HNO3, H2SO4, NF3 and O3. Choose the correct bond angle made by the central atom of the molecule (X).
- 107
- 102
- 120
- 116
Answer
(2) 102
Solution
Lone pairs in the Lewis structures:
HNO3: N=O (2) + N-O- (3) + O–H (2) = 7 lone pairs
H2SO4: two S=O (2 each) + two S–OH (2 each) = 8 lone pairs
NF3: three F (3 each) + N (1) = 10 lone pairs
O3: central O (1) + O= (2) + O- (3) = 6 lone pairs
X = NF3
NF3 is pyramidal (sp3 N with one lone pair); the lone pair and the highly electronegative F atoms (bond pairs drawn towards F) reduce the angle below that of NH3 (107°): F–N–F = 102
Answer: (2)