JEE Main 20 July 2021 Shift 1 Solved Paper

[Co(CN)6]4−
x+6×(−1)=−4
x=+2
Co2+:[Ar]3d7
and CN−is a strong field ligand which can pair electron of central atom.
It has one unpaired electron (n) in 4 d-subshell.
So spin only magnetic moment (µ)= √n(n+2) B.M
where n= number of unpaired electrons.
µ=√3 B.M
µ=1.73BM