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JEE Main 20254 AprilEvening Shift
Exam
JEE Main
Year
2025
Date
4 April
Shift
Evening Shift
Subject
Chemistry
Chapter
Coordination Compounds

JEE Main 2025 · 4 April · Evening Shift · Chemistry · Coordination Compounds

The correct order of [FeF_6]^ 3- ,[CoF_6]^ 3- , [Ni(CO)_4] and...

The correct order of [FeF6]3−,[CoF6]3−,\left[\mathrm{FeF}_6\right]^{3-},\left[\mathrm{CoF}_6\right]^{3-},\left[\mathrm{Ni}(\mathrm{CO})_4\right]and[Ni(CN)4]2−and \left[\mathrm{Ni}(\mathrm{CN})_4\right]^{2-} complex species based on the number of unpaired electrons present is :The correct order of [FeF_6]^ 3- ,[CoF_6]^ 3- , [Ni(CO)_4] and [Ni(CN)_4]^ 2- complex species based on the number of

Options

  1. A[FeF6]3−>[CoF6]3−>[Ni(CN)4]2−>[Ni(CO)4]\left[\mathrm{FeF}_6\right]^{3-} \gt \left[\mathrm{CoF}_6\right]^{3-} \gt \left[\mathrm{Ni}(\mathrm{CN})_4\right]^{2-} \gt \left[\mathrm{Ni}(\mathrm{CO})_4\right]
  2. B[Ni(CN)4]2−>[FeF6]3−>[CoF6]3−>[Ni(CO)4]\left[\mathrm{Ni}(\mathrm{CN})_4\right]^{2-} \gt \left[\mathrm{FeF}_6\right]^{3-} \gt \left[\mathrm{CoF}_6\right]^{3-} \gt \left[\mathrm{Ni}(\mathrm{CO})_4\right]
  3. C[CoF6]3−>\left[\mathrm{CoF}_6\right]^{3-} \gt\left[\mathrm{FeF}_6\right]^{3-} \gt [Ni(CO)4]>[Ni(CN)4]2−\left[\mathrm{Ni}(\mathrm{CO})_4\right] \gt \left[\mathrm{Ni}(\mathrm{CN})_4\right]^{2-}
  4. D[FeF6]3−>[CoF6]3−>[Ni(CN)4]2−=[Ni(CO)4]\left[\mathrm{FeF}_6\right]^{3-} \gt \left[\mathrm{CoF}_6\right]^{3-} \gt \left[\mathrm{Ni}(\mathrm{CN})_4\right]^{2-}=\left[\mathrm{Ni}(\mathrm{CO})_4\right]

Correct answer

D. [FeF6]3−>[CoF6]3−>[Ni(CN)4]2−=[Ni(CO)4]\left[\mathrm{FeF}_6\right]^{3-} \gt \left[\mathrm{CoF}_6\right]^{3-} \gt \left[\mathrm{Ni}(\mathrm{CN})_4\right]^{2-}=\left[\mathrm{Ni}(\mathrm{CO})_4\right]

Step-by-step solution

The correct order of [FeF_6]^ 3- ,[CoF_6]^ 3- , [Ni(CO)_4] and [Ni(CN)_4]^ 2- complex species based on the number of
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