JEE Main202124 Feb 2021Evening ShiftChemistryCoordination CompoundsActual
The calculated magnetic moments (spin only value) for species FeCl 4 2 - , Co C 2 O 4 3 3 - and MnO 4 2 - respectively are:
Options
- A4 . 90 ,   0 and 1 . 73   BM
- B4 . 90 ,   0 and 2 . 83   BM
- C5 . 82 ,   0 and 0   BM
- D5 . 92 ,   4 . 90 and 0   BM
Correct answer
A. 4 . 90 ,   0 and 1 . 73   BM
Step-by-step solution
(i) FeCl 4 2 -   Fe 2 +   3 d 6 → 4 unpaired electrons. μ = n n + 2 BM = 4 4 + 2 BM = 24   BM ⇒ 4 . 90   BM (ii) Co C 2 O 4 3 - 3 is a strong field ligand & causes pairing & hence no. unpaired electron μ = 0 (iii) MnO 4 2 -     Mn + 6 it has one unpaired electron. Mn + 6 ⇒ Ar 3   d 1    μ = n n + 2 BM = 1 1 + 2 BM = 3 BM ⇒ 1 . 73   BM