Arrange the following in the increasing order of oxidation state of nitrogen:
A. \(NO\)
B. \(NO_2\)
C. \(N_2O_5\)
D. \(N_2O\)
E. \(N_2O_3\)
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → D < A < E < B < C
Taking the oxidation state of oxygen as −2 and that of nitrogen as x, the oxidation states in a neutral molecule add up to zero.
(D) \( \ce{N2O} \): 2x − 2 = 0 ⇒ x = +1. It comes first, with the lowest oxidation state.
(A) \( \ce{NO} \): x − 2 = 0 ⇒ x = +2. It comes second.
(E) \( \ce{N2O3} \): 2x − 6 = 0 ⇒ x = +3. It comes third.
(B) \( \ce{NO2} \): x − 4 = 0 ⇒ x = +4. It comes fourth.
(C) \( \ce{N2O5} \): 2x − 10 = 0 ⇒ x = +5. It comes last, with the highest oxidation state.
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 – …
