JEE MainChemistrySolid State
Consider the following statements regarding the magnetic properties of solid substances: (A) Fe ₃ O ₄ is ferrimagnetic at room temperature but becomes paramagnetic upon heating. (B) MnO is antiferromagnetic because its magnetic domains are aligned in parallel and anti-parallel directions in equal numbers. (C) CrO ₂ is an example of a ferrimagnetic substance and is widely used in making magnetic tapes. (D) NaCl is a d
Options
- AStatement (A)
- BStatement (B)
- CStatement (D)
- DStatement (C)
Correct answer
D. Statement (C)
Step-by-step solution
Let us evaluate each statement: (A) True. Fe ₃ O ₄ is ferrimagnetic, but on heating, the alignment of its magnetic domains becomes randomized, and it transitions to a paramagnetic state. (B) True. MnO exhibits antiferromagnetism, where domains are aligned in parallel and anti-parallel directions in equal numbers, cancelling out each other's magnetic moments completely. (C) False. CrO ₂ is a ferromagnetic substance (where all magnetic domains align in the same direction), not ferrimagnetic. It is indeed used in the