Answer the question on the basis of passage given below:
Nitrogen differs from rest of the members of group 15 due to its small size, high electronegativity, high ionization enthalpy and non-availability of d orbitals. Nitrogen has unique ability to form \(p\pi -p\pi \) multiple bonds with itself and with other elements having small size and high electronegativity. Heavier elements of this group do not form \(p\pi -p\pi \) bonds as their atomic orbitals are so large and diffuse that they cannot have effective overlapping.
Planar structures with \(N-N\) single bond are shown by
A. \(N_2O_3\)
B. \(N_2O_4\)
C. \(N_2O_5\)
D. \(N_2O\)
E. \(NO\)
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → A and B only
Two checks decide each oxide: does it contain an N–N single bond, and is the molecule planar?
(A) \( \ce{N2O3} \) — True. \( \ce{O=N-NO2} \): the two N atoms are joined by a long N–N single bond, and the molecule is planar.
(B) \( \ce{N2O4} \) — True. \( \ce{O2N-NO2} \), the dimer of \( \ce{NO2} \): an N–N single bond, and the molecule is planar.
(C) \( \ce{N2O5} \) — False. \( \ce{O2N-O-NO2} \): the two N atoms are joined through an O atom, so there is no N–N bond.
(D) \( \ce{N2O} \) — False. N=N=O ↔ N≡N–O: the N–N bond is a multiple bond and the molecule is linear.
(E) NO — False. It has only one N atom, so it cannot have an N–N bond.
Note: This question is from the pre-rationalised NCERT book (2022-23). The topic is not there in the latest NCERT book (2026-27), and it is also out of the CUET 2026 syllabus.
NCERT (Pre-rationalised edition, 2022-23):
Oxides of Nitrogen – …
