Question

Assertion : $[Fe(H_2O)_5NO]SO_4$ is paramagnetic.
Reason : The $Fe$ in $[Fe(H_2O)_5NO]SO_4$ has three unpaired electrons.

• A. If both assertion and reason are true and reason is the correct explanation of assertion
• B. If both assertion and reason are true but reason is not the correct explanation of assertion
• C. If assertion is true but reason is false
• D. If both assertion and reason are false

Answer 1

Answer: (A)

Fe⁺ : [Ar] 3d⁶ 4s¹
When the weak field ligand H₂O and strong field ligand NO attack, the configuration changes as follows:
Fe⁺ : [Ar] 3d⁷ 4s⁰
∴ Fe⁺ has 3 unpaired electrons.