NEET Chemistry Coordination Chemistry Question Bank Self Evaluation Test - Co-ordination Compounds

Among the following complexes (K-P)

\[{{K}_{3}}\left[ Fe{{\left( CN \right)}_{6}} \right]\]         (K),   \[\left[ Co{{\left( N{{H}_{3}} \right)}_{6}} \right]C{{l}_{3}}\text{ }\left( L \right),\]

\[N{{a}_{3}}\left[ Co{{\left( oxalate \right)}_{3}} \right]\] (M), \[[Ni{{({{H}_{2}}O)}_{6}}]C{{l}_{2}})(N),\]

\[{{K}_{2}}[Pt{{\left( CN \right)}_{4}}\left( O \right)\] and \[[Zn{{({{H}_{2}}O)}_{6}}]{{(N{{O}_{3}})}_{2}}(P)\] the

diamagnetic complexes are

A) K, L, M, N

B) K, M, O, P

C) L, M, O, P

D) L, M, N, O

Correct Answer: C

Solution :

[c]

Complex	No. of electrons in outer d orbital	No. of unpaired electrons (s)
\[{{[Fe{{(CN)}_{6}}]}^{3-}}\]	\[3{{d}^{5}}\]	1 (\[C{{N}^{-}}\] causes pairing of electrons)
\[{{[Co{{(N{{H}_{3}})}_{6}}]}^{3-}}\]	\[3{{d}^{6}}\]	0
\[{{[Co{{(OX)}_{3}}]}^{3-}}\]	\[3{{d}^{6}}\]	0
\[{{[Ni{{({{H}_{2}}O)}_{6}}]}^{2+}}\]	\[3{{d}^{8}}\]	2
\[{{[Pt{{(CN)}_{4}}]}^{2-}}\]	\[5{{d}^{8}}\]	0 (\[C{{N}^{-}}\] cause pairing of electrons)
\[{{[Zn{{({{H}_{2}}O)}_{6}}]}^{2+}}\]	\[3{{d}^{10}}\]	0

Thus L, M, O and P are diamagnetic.