Which amongst the following compounds is a diamagnetic compound?
\(C_6H_6, CrO_2, MnO, MgFe_2O_4\)
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → \(C_6H_6\)
Benzene is a covalent molecule in which every electron is paired in a bond, so C6H6 is diamagnetic.
Why the other options are incorrect
Option (1) \(CrO_2\) — Incorrect. Ferromagnetic; it is the oxide used in audio and video tapes.
Option (3) \(MnO\) — Incorrect. Antiferromagnetic; \( \ce{Mn^{2+}} \) (Z = 25, [Ar]3d54s2, minus the two 4s electrons: 3d5) has five unpaired electrons, but the moments of neighbouring domains cancel.
Option (4) \(MgFe_2O_4\) — Incorrect. Ferrimagnetic, like the other ferrites.
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):
Magnetic Properties – …
