Which of the following is paramagnetic ?

see full answer

High-Paying Jobs That Even AI Can’t Replace — Through JEE/NEET

🎯 Hear from the experts why preparing for JEE/NEET today sets you up for future-proof, high-income careers tomorrow.

An Intiative by Sri Chaitanya

V(CO)₆

Fe(CO)₅

Fe₂(CO)₉

Cr(CO)₆

answer is A.

(Unlock A.I Detailed Solution for FREE)

Best Courses for You

JEE

NEET

Foundation JEE

Foundation NEET

CBSE

Detailed Solution

CO is a neutral ligand, so all metal ions are in zero oxidation state.

(i) V(CO)₆

Oxidation state of V is zero and its electronic configuration is [Ar] 3d³ 4s². As CO is a strong ligand, so all electrons of 3d and 4s gets paired leaving one unpaired electrons which is responsible for its paramagnetic behavior.

(ii) Fe(CO)₆

Oxidation state of Fe is zero and its electronic configuration is [Ar] 3d⁶ 4s². As CO is a strong ligand, so all electrons of 3d and 4s gets paired leaving no unpaired electrons, so it is diamagnetic.

(ii) Fe₂(CO)₉

Oxidation state of Fe is zero and its electronic configuration is [Ar] 3d⁶ 4s². Complex is diamagnetic because each Fe has one unpaired electron which combine together and forms a Fe-Fe bond.

(ii) Cr(CO)₆

Oxidation state of Cr is zero and its electronic configuration is [Ar] 3d⁵ 4s¹. As CO is a strong ligand, so all electrons of 3d and 4s gets paired leaving no unpaired electrons, so it is diamagnetic.

Watch 3-min video & get full concept clarity