Question

$K:K_4\left[Mn\right(CN{)}_6],L:K_3[Co\left(N{O}_2{)}_6\right],M:\left[Co\right(H_{2}O{)}_6]C{l}_3,N:[Cr\left(CO{)}_6\right],O:\left[Ni\right(en{)}_3\left]\right(N{O}_3{)}_3$

$P:\left[Pt\right(N{H}_3{)}_{2}C{l}_2]$

The diamagnetic complexes are :

• A. L, M, N, P
• B. K, L, N, O
• C. L, M, O, P
• D. K, N, O, P

Answer 1

Answer: (A)

L, M, N, P

The complex K having structure $K_4\left[Mn\right(CN{)}_6]$ has $3d^5$ electron configuration. It undergoes $d^{2}s{p}^3$ hybridization. It contains one unpaired electron and is paramagnetic.
The complex L having structure $K_3\left[Co\right(N{O}_2{)}_6]$ has $3d^6$ electron configuration. It undergoes $d^{2}s{p}^3$ hybridization. It contains no unpaired electron and is diamagnetic.
The complex M having structure $\left[Co\right(H_{2}O{)}_6]C{l}_3$ has $3d^6$ electron configuration. It undergoes $d^{2}s{p}^3$ hybridisation. It contains no unpaired electron and is diamagnetic.
The complex N having structure $\left[Cr\right(CO\left)6\right]$ has $3d^6$ electron configuration. It undergoes $d^{2}s{p}^3$ hybridization. It contains no unpaired electron and is diamagnetic.
The complex O having structure $\left[Ni\right(en{)}_3\left]\right(N{O}_3{)}_3$ has $3d^8$ electron configuration. It undergoes $s{p}^3{d}^2$ hybridization. It contains two unpaired electron and is paramagnetic.
The complex P having structure $\left[Pt\right(N{H}_3{)}_{2}C{l}_2]$ has $5d^8$ electron configuration. It undergoes $ds{p}^3$ hybridization. It contains no unpaired electron and is diamagnetic.