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Coordination Compounds · Question 45

JEE Main 2025 (Online) 4th April Evening ShiftMCQEasy📈 Topic in 42% papers+4−1
1

The correct order of [FeF6]3-, [CoF6]3-, [Ni(CO)4] and [Ni(CN)4]2- complex species based on the number of unpaired electrons present is:

  1. [CoF6]3- > [FeF6]3- > [Ni(CO)4] > [Ni(CN)4]2-
  2. [FeF6]3- > [CoF6]3- > [Ni(CN)4]2- > [Ni(CO)4]
  3. [FeF6]3- > [CoF6]3- > [Ni(CN)4]2- = [Ni(CO)4]
  4. [Ni(CN)4]2- > [FeF6]3- > [CoF6]3- > [Ni(CO)4]

Answer

(3) [FeF6]3- > [CoF6]3- > [Ni(CN)4]2- = [Ni(CO)4]

Solution

[FeF6]3-: Fe3+, 3d5, F- weak field (high spin, sp3d2) 5 unpaired

[CoF6]3-: Co3+, 3d6, high spin 4 unpaired

[Ni(CN)4]2-: Ni2+, 3d8, CN- strong field, dsp2 (square planar) 0 unpaired

[Ni(CO)4]: Ni(0), 3d10 (4s electrons paired into 3d), sp3 0 unpaired

[FeF6]3- > [CoF6]3- > [Ni(CN)4]2- = [Ni(CO)4]

Answer: (3)

JEE Main 2025 (Online) 4th April Evening Shift

Keep practising — Coordination Compounds

2

A metal complex with a formula MCl4 3NH3 is involved in sp3d2 hybridisation. It upon reaction with excess of AgNO3 solution gives 'x' moles of AgCl. Consider 'x' is equal to the number of lone pairs of electrons present in the central atom of BrF5. Then the number of geometrical isomers exhibited by the complex is .

JEE Main 2025 (Online) 4th April Evening Shift
3

The correct order of the complexes [Co(NH3)5(H2O)]3+ (A), [Co(NH3)6]3+ (B), [Co(CN)6]3- (C) and [CoCl(NH3)5]2+ (D) in terms of wavelength of light absorbed is

  1. D > C > B > A
  2. C > B > A > D
  3. D > A > B > C
  4. C > B > D > A
JEE Main 2025 (Online) 3rd April Morning Shift
4

The number of optical isomers exhibited by the iron complex (A) obtained from the following reaction is . FeCl3 + KOH + H2C2O4 A

JEE Main 2025 (Online) 3rd April Morning Shift
5

Identify the diamagnetic octahedral complex ions from below ; Choose the correct answer from the options given below:

  1. B and C Only
  2. A and C Only
  3. B and D Only
  4. A and D Only
JEE Main 2025 (Online) 3rd April Evening Shift
6

Given below are two statements : In the light of the above statements, choose the most appropriate answer from the options given below :

  1. Both Statement I and Statement II are incorrect
  2. Statement I is correct but Statement II is incorrect
  3. Statement I is incorrect but Statement II is correct
  4. Both Statement I and Statement II are correct
JEE Main 2025 (Online) 2nd April Morning Shift
7

A transition metal (M) among Mn, Cr, Co and Fe has the highest standard electrode potential (M3+/M2+). It forms a metal complex of the type [M(CN)6]4-. The number of electrons present in the eg orbital of the complex is .

JEE Main 2025 (Online) 2nd April Morning Shift
8

The type of hybridization and the magnetic property of [MnCl6]3- are,

  1. sp3d2, paramagnetic with four unpaired electrons.
  2. d2sp3, paramagnetic with four unpaired electrons.
  3. sp3d2, paramagnetic with two unpaired electrons.
  4. d2sp3, paramagnetic with two unpaired electrons.
JEE Main 2025 (Online) 2nd April Evening Shift
9

The d-orbital electronic configuration of the complex among [Co(en)3]3+, [CoF6]3-, [Mn(H2O)6]2+ and [Zn(H2O)6]2+ that has the highest CFSE is:

  1. t2g6eg0
  2. t2g3eg2
  3. t2g4eg2
  4. t2g6eg4
JEE Main 2025 (Online) 2nd April Evening Shift
10

The correct increasing order of stability of the complexes based on 0 value is : I. [Mn(CN)6]3- II. [Co(CN)6]4- III. [Fe(CN)6]4- IV. [Fe(CN)6]3-

  1. I < II < IV < III
  2. IV < III < II < I
  3. III < II < IV < I
  4. II < III < I < IV
JEE Main 2025 (Online) 29th January Morning Shift
11

Match List - I with List - II. Choose the correct answer from the options given below :

  1. (A)-(III), (B)-(I), (C)-(I), (D)-(IV)
  2. (A)-(III), (B)-(II), (C)-(III), (D)-(IV)
  3. (A)-(IV), (B)-(II), (C)-(I), (D)-(III)
  4. (A)-(IV), (B)-(I), (C)-(II), (D)-(III)
JEE Main 2025 (Online) 29th January Morning Shift

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