JEE PYQ: Coordination Compounds Question 6
Question 6 - 2021 (24 Feb Shift 2)
The calculated magnetic moments (spin only value) for species $[\text{FeCl}_4]^{2-}$, $[\text{Co(C}_2\text{O}_4)_3]^{3-}$ and $\text{MnO}_4^-$ respectively are:
(a) 5.92, 4.90 and 0 BM (b) 5.92, 0 and 0 BM (c) 4.90, 0 and 1.73 BM (d) 4.90, 0 and 2.83 BM
Show Answer
Answer: (a)
Solution
$[\text{FeCl}_4]^{2-}$: Fe$^{2+}$ $3d^6$, weak field $\rightarrow$ 4 unpaired electrons, $\mu = 4.9$ BM. $[\text{Co(C}_2\text{O}_4)_3]^{3-}$: Co$^{3+}$ $3d^6$, strong field causes pairing, $\mu = 0$. $\text{MnO}_4^-$: Mn$^{7+}$ $3d^0$, $\mu = 0$.
BETA
