In which of the following oxides of halogens is the oxidation state of the halogen different from that in the remaining oxides?
A. \(ClO_2\)
B. \(Cl_2O_3\)
C. \(BrO_2\)
D. \(I_2O_4\)
E. \(I_2O_5\)
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → B and E only
The oxidation state x of the halogen in an oxide follows from the charge balance, taking oxygen as −2 and the total as zero.
A. ClO2 — Incorrect. x + 2(−2) = 0, so x = +4, the same as in \( \ce{BrO2} \) and \( \ce{I2O4} \).
B. Cl2O3 — Correct. 2x + 3(−2) = 0, so x = +3, different from the +4 of A, C and D.
C. BrO2 — Incorrect. x + 2(−2) = 0, so x = +4.
D. I2O4 — Incorrect. 2x + 4(−2) = 0, so x = +4.
E. I2O5 — Correct. 2x + 5(−2) = 0, so x = +5, different from the +4 of A, C and D.
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.