Which one of the following species has plane triangular shape?
- N3-
- NO3-
- NO2-
- CO2
Answer
(2) NO3-
Solution
N3- and CO2: 2 σ-bond pairs, no lone pair on central atom ⇒ sp, linear.
NO2-: 2 bond pairs + 1 lone pair on N ⇒ sp2, bent (V-shaped).
NO3-: 3 bond pairs, no lone pair on N ⇒ sp2, plane triangular (trigonal planar).
Answer: (2)