The correct order of increasing bond angles in the following triatomic species is
- NO2+ < NO2 < NO2-
- NO2+ < NO2- < NO2
- NO2- < NO2+ < NO2
- NO2- < NO2 < NO2+
Answer
(4) NO2- < NO2 < NO2+
Solution
NO2+: N is sp hybridised with no lone pair ⇒ linear, bond angle 180°.
NO2: N carries one unpaired (single) electron ⇒ angular, bond angle ≈ 134°.
NO2-: N carries one lone pair ⇒ angular, bond angle ≈ 115°.
∵ A lone pair repels bond pairs more strongly than a single electron, the angle in NO2- is the smallest.
∴ Increasing bond angle: NO2- < NO2 < NO2+
Answer: (4)