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.
Match List I with List II
|
LIST I (Nitrogen Oxide) |
LIST II (Oxidation state) |
| A. \(N_2O\) | I. \(+3\) |
| B. \(N_2O_3\) | II. \(+5\) |
| C. \(N_2O_4\) | III. \(+1\) |
| D. \(N_2O_5\) | IV. \(+4\) |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → A-III, B-I, C-IV, D-II
Taking oxygen as −2, the oxidation state x of nitrogen in N2On follows from 2x + n(−2) = 0, so x = n.
(A) N2O — This matches (III) +1. 2x − 2 = 0, so x = +1.
(B) N2O3 — This matches (I) +3. 2x − 6 = 0, so x = +3.
(C) N2O4 — This matches (IV) +4. 2x − 8 = 0, so x = +4.
(D) N2O5 — This matches (II) +5. 2x − 10 = 0, so x = +5.
Shortcut: in N2On the oxidation state of N equals n. B-I (+3 for N2O3) appears only in Option (2).
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 – “Nitrogen forms a number of oxides in different oxidation states. The names, formulas, preparation and physical appearance of these oxides are given in Table 7.3.”
Oxides of Nitrogen (Table 7.3, columns)
| Name | Formula | Oxidation state of nitrogen |
|---|---|---|
| Dinitrogen oxide [Nitrogen(I) oxide] | N2O | + 1 |
| Nitrogen monoxide [Nitrogen(II) oxide] | NO | + 2 |
| Dinitrogen trioxide [Nitrogen(III) oxide] | N2O3 | + 3 |
| Nitrogen dioxide [Nitrogen(IV) oxide] | NO2 | + 4 |
| Dinitrogen tetroxide [Nitrogen(IV) oxide] | N2O4 | + 4 |
| Dinitrogen pentoxide [Nitrogen(V) oxide] | N2O5 | + 5 |