iCON Education - Coordination Compounds JEE Mains Test

Candidate Name

Student

Exam Name

JEE Mains

Test Name

Coordination Compounds

Subject

Chemistry

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Remaining Time

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Question 1: Palette 1/274

JEE Mains 2026 MCQ

The correct increasing order of spin-only magnetic moment values of the complex ions

[MnBr₄]²⁻ (A), [Cu(H₂O)₆]²⁺ (B), [Ni(CN)₄]²⁻ (C) and [Ni(H₂O)₆]²⁺ (D) is :

A = B < D < C

C = D < B < A

C < B < D < A

A = B < C < D

Question 2: Palette 2/274

JEE Mains 2026 MCQ

The correct statement among the following is:

$\left[\mathrm{Ni}(\mathrm{CN})_4\right]^{2-}$ and $\left[\mathrm{NiCl}_4\right]^{2-}$ are diamagnetic and $\mathrm{Ni}(\mathrm{CO})_4$ is paramagnetic.

$\mathrm{Ni}(\mathrm{CO})_4$ is diamagnetic and $\left[\mathrm{NiCl}_4\right]^{2-}$ and $\left[\mathrm{Ni}(\mathrm{CN})_4\right]^{2-}$ are paramagnetic.

$\mathrm{Ni}(\mathrm{CO})_4$ and $\left[\mathrm{NiCl}_4\right]^{2-}$ are diamagnetic and $\left[\mathrm{Ni}(\mathrm{CN})_4\right]^{2-}$ is paramagnetic.

$\mathrm{Ni}(\mathrm{CO})_4$ and $\left[\mathrm{Ni}(\mathrm{CN})_4\right]^{2-}$ are diamagnetic and $\left[\mathrm{NiCl}_4\right]^{2-}$ is paramagnetic.

Question 3: Palette 3/274

JEE Mains 2026 MCQ

$ \text { The wavelength of light absorbed for the following complexes are in the order } $

JEE Main 2026 (Online) 24th January Evening Shift Chemistry - Coordination Compounds Question 20 English

III $<$ IV $<$ I $<$ II $<$ V

III $<$ I $<$ IV $<$ V $<$ II

III $<$ I $<$ IV $<$ II $<$ V

III $<$ I $<$ II $<$ IV $<$ V

Question 4: Palette 4/274

JEE Mains 2026 MCQ

Given below are two statements :

Statement I : Hybridisation, shape and spin only magnetic moment of $\mathrm{K}_3\left[\mathrm{Co}\left(\mathrm{CO}_3\right)_3\right]$ is $\mathrm{sp}^3 \mathrm{~d}^2$, octahedral and 4.9 BM respectively.

Statement II : Geometry, hybridisation and spin only magnetic moment values $(B M)$ of the ions $\left[\mathrm{Ni}(\mathrm{CN})_4\right]^{2-},\left[\mathrm{MnBr}_4\right]^{2-}$ and $\left[\mathrm{CoF}_6\right]^{3-}$ respectively are square planar, tetrahedral, octahedral; $\mathrm{dsp}^2, \mathrm{sp}^3, \mathrm{sp}^3 \mathrm{~d}^2$ and $0,5.9,4.9$.

In the light of the above statements, choose the correct answer from the options given below

Both Statement I and Statement II are false

Statement I is true but Statement II is false

Both Statement I and Statement II are true

Statement I is false but Statement II is true

Question 5: Palette 5/274

JEE Mains 2026 MCQ

Given below are two statements:

Statement I : The number of paramagnetic species among $\left[\mathrm{CoF}_6\right]^{3-},\left[\mathrm{TiF}_6\right]^{3-}$, $\mathrm{V}_2 \mathrm{O}_5$ and $\left[\mathrm{Fe}(\mathrm{CN})_6\right]^{3-}$ is 3 .

Statement II :

$\mathrm{K}_4\left[\mathrm{Fe}(\mathrm{CN})_6\right]<\mathrm{K}_3\left[\mathrm{Fe}(\mathrm{CN})_6\right]<\left[\mathrm{Fe}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right] \mathrm{SO}_4 \cdot \mathrm{H}_2 \mathrm{O}<\left[\mathrm{Fe}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right] \mathrm{Cl}_3$ is the correct order in terms of number of unpaired electron(s) present in the complexes.

In the light of the above statements, choose the correct answer from the options given below

Statement I is true but Statement II is false

Both Statement I and Statement II are false

Statement I is false but Statement II is true

Both Statement I and Statement II are true

Question 6: Palette 6/274

JEE Mains 2026 MCQ

Consider a mixture ' X ' which is made by dissolving 0.4 mol of $\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_5 \mathrm{SO}_4\right] \mathrm{Br}$ and 0.4 mol of $\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_5 \mathrm{Br}\right] \mathrm{SO}_4$ in water to make 4 L of solution. When 2 L of mixture ' X ' is allowed to react with excess of $\mathrm{AgNO}_3$, it forms precipitate ' Y '. The rest 2 L of mixture ' X ' reacts with excess $\mathrm{BaCl}_2$ to form precipitate ' Z '. Which of the following statements is CORRECT?

0.1 mol of ' $Y$ ' is formed.

0.4 mol of ' $Z$ ' is formed.

0.2 mol of ' $Z$ ' is formed.

' Y ' is $\mathrm{BaSO}_4$ and ' Z ' is AgBr .

Question 7: Palette 7/274

JEE Mains 2026 MCQ

Identify the CORRECT set of details from the following :

A. $\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_6\right]^{3+}$ : Inner orbital complex; $\mathrm{d}^2 \mathrm{sp}^3$ hybridized

B. $\left[\mathrm{MnCl}_6\right]^{3-}$ : Outer orbital complex; $\mathrm{sp}^3 \mathrm{~d}^2$ hybridized

C. $\left[\mathrm{CoF}_6\right]^{3-}$ : Outer orbital complex; $\mathrm{d}^2 \mathrm{sp}^3$ hybridized

D. $\left[\mathrm{FeF}_6\right]^{3-}$ : Outer orbital complex; $\mathrm{sp}^3 \mathrm{~d}^2$ hybridized

E. $\left[\mathrm{Ni}(\mathrm{CN})_4\right]^{2-}$ : Inner orbital complex; $\mathrm{sp}^3$ hybridized

Choose the correct answer from the options given below :

C & D Only

A, C & E Only

A, B, C, D & E

A, B & D Only

Question 8: Palette 8/274

JEE Mains 2026 MCQ

The statements that are incorrect about the nickel(II) complex of dimethylglyoxime are :

A. It is red in colour.

B. It has a high solubility in water at $\mathrm{pH}=9$.

C. The Ni ion has two unpaired d-electrons.

D. The $\mathrm{N}-\mathrm{Ni}-\mathrm{N}$ bond angle is almost close to $90^{\circ}$.

E. The complex contains four five-membered metallacycles (metal containing rings).

Choose the correct answer from the options given below :

C and E Only

A, D and B Only

B, C and E Only

C and D Only

Question 9: Palette 9/274

JEE Mains 2026 MCQ

Given below are two statements :

Statement I : $\left[\mathrm{CoBr}_4\right]^{2-}$ ion will absorb light of lower energy than $\left[\mathrm{CoCl}_4\right]^{2-}$ ion.

Statement II : In $\left[\mathrm{CoI}_4\right]^{2-}$ ion, the energy separation between the two set of d-orbitals is more than $\left[\mathrm{CoCl}_4\right]^{2-}$ ion.

In the light of the above statements, choose the correct answer from the options given below :

Both Statement I and Statement II are false

Both Statement I and Statement II are true

Statement I is false but Statement II is true

Statement I is true but Statement II is false

Question 10: Palette 10/274

JEE Mains 2026 MCQ

$\left[\mathrm{Ni}\left(\mathrm{PPh}_3\right)_2 \mathrm{Cl}_2\right]$ is a paramagnetic complex. Identify the INCORRECT statements about this complex.

A. The complex exhibits geometrical isomerism.

B. The complex is white in colour.

C. The calculated spin-only magnetic moment of the complex is 2.84 BM .

D. The calculated CFSE (Crystal Field Stabilization Energy) of Ni in this complex is $-0.8 \Delta_{\mathrm{o}}$.

E. The geometrical arrangement of ligands in this complex is similar to that in $\mathrm{Ni}(\mathrm{CO})_4$.

Choose the correct answer from the options given below :

C and D Only

A, B and D Only

C, D and E Only

A and B Only

Question 11: Palette 11/274

JEE Mains 2026 MCQ

Consider the transition metal ions $\mathrm{Mn}^{3+}, \mathrm{Cr}^{3+}, \mathrm{Fe}^{3+}$ and $\mathrm{Co}^{3+}$ and all form low spin octahedral complexes. The correct decreasing order of unpaired electrons in their respective d-orbitals of the complexes is

$\mathrm{Cr}^{3+}>\mathrm{Mn}^{3+}>\mathrm{Fe}^{3+}>\mathrm{Co}^{3+}$

$\mathrm{Mn}^{3+}>\mathrm{Fe}^{3+}>\mathrm{Co}^{3+}>\mathrm{Cr}^{3+}$

$\mathrm{Fe}^{3+}>\mathrm{Co}^{3+}>\mathrm{Mn}^{3+}>\mathrm{Cr}^{3+}$

$\mathrm{Cr}^{3+}>\mathrm{Fe}^{3+}>\mathrm{Co}^{3+}>\mathrm{Mn}^{3+}$

Question 12: Palette 12/274

JEE Mains 2026 MCQ

A first row transition metal $(\mathrm{M})$ does not liberate $\mathrm{H}_2$ gas from dilute HCl .1 mol of aqueous solution of $\mathrm{MSO}_4$ is treated with excess of aqueous KCN and then $\mathrm{H}_2 \mathrm{~S}(\mathrm{~g})$ is passed through the solution. The amount of MS (metal sulphide) formed from the above reaction is $\_\_\_\_$ mol.

Question 13: Palette 13/274

JEE Mains 2026 MCQ

Given below are two statements :

Statement I : Crystal Field Stabilization Energy (CFSE) of [Cr(H₂O)₆]²⁺ is greater than that of [Mn(H₂O)₆]²⁺.

Statement II : Potassium ferricyanide has a greater spin-only magnetic moment than sodium ferrocyanide.

In the light of the above statements, choose the correct answer from the options given below :

Statement I is true but Statement II is false

Both Statement I and Statement II are true

Both Statement I and Statement II are false

Statement I is false but Statement II is true

Question 14: Palette 14/274

JEE Mains 2026 MCQ

Given below are two statements :

Statement I : Among $\left.\left[\mathrm{Cu}\left(\mathrm{NH}_3\right)_4\right]^{2+},\left[\mathrm{Ni}(\mathrm{en})_3\right)\right]^{2+},\left[\mathrm{Ni}\left(\mathrm{NH}_3\right)_6\right]^{2+}$ and $\left[\mathrm{Mn}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+}$, $\left[\mathrm{Mn}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+}$ has the maximum number of unpaired electrons.

Statement II : The number of pairs among $\left\{\left[\mathrm{NiCl}_4\right]^{2-},\left[\mathrm{Ni}(\mathrm{CO})_4\right]\right\},\left\{\left[\mathrm{NiCl}_4\right]^{2-},\left[\mathrm{Ni}(\mathrm{CN})_4\right]^{2-}\right\}$ and $\left\{\left[\mathrm{Ni}(\mathrm{CO})_4\right],\left[\mathrm{Ni}(\mathrm{CN})_4\right]^{2-}\right\}$ that contain only diamagnetic species is two.

In the light of the above statements, choose the correct answer from the options given below :

Statement I is false but Statement II is true

Both Statement I and Statement II are false

Both Statement I and Statement II are true

Statement I is true but Statement II is false

Question 15: Palette 15/274

JEE Mains 2026 MCQ

Which of the following sequences of hybridisation, geometry and magnetic nature are correct for the given coordination compounds?

A. $\left[\mathrm{NiCl}_4\right]^{2-}-\mathrm{sp}^3$, tetrahedral, paramagnetic

B. $\left[\mathrm{Ni}\left(\mathrm{NH}_3\right)_6\right]^{2+}-\mathrm{sp}^3 \mathrm{~d}^2$, octahedral, paramagnetic

C. $\left[\mathrm{Ni}(\mathrm{CO})_4\right]-\mathrm{sp}^3$, tetrahedral, paramagnetic

D. $\left[\mathrm{Ni}(\mathrm{CN})_4\right]^{2-}-\mathrm{dsp}^2$, square planar, diamagnetic

Choose the correct answer from the options given below :

A, B, C and D

B, C and D only

A, C and D only

A, B and D only

Question 16: Palette 16/274

JEE Mains 2026 MCQ

$ \text { Match the LIST-I with LIST-II } $

List-I Electronic configuration of tetrahedral metal ion		$ \begin{gathered} \text { List-II } \\ \text { Crystal Field Stabilization } \\ \text { Energy }\left(\Delta_t\right) \end{gathered} $
A.	$ \mathrm{d}^2 $	I.	-0.6
B.	$ \mathrm{d}^4 $	II.	-0.8
C.	$ \mathrm{d}^6 $	III.	-1.2
D.	$ \mathrm{d}^8 $	IV.	-0.4

Choose the correct answer from the options given below:

A-III, B-IV, C-II, D-I

A-III, B-I, C-IV, D-II

A-III, B-IV, C-I, D-II

A-II, B-I, C-IV, D-III

Question 18: Palette 18/274

JEE Mains 2026 MCQ

Given below are two statements :

Statement I : Presence of large number of unpaired electrons in transition metal atoms results in higher enthalpies of their atomisation.

Statement II : $\quad \mathrm{d}_{x y}=\mathrm{d}_{x z}=\mathrm{d}_{y z}<\mathrm{d}_{x^2-y^2}=\mathrm{d}_{z^2}$ and $\mathrm{d}_{x^2-y^2}=\mathrm{d}_{z^2}<\mathrm{d}_{x y}=\mathrm{d}_{x z}=\mathrm{d}_{y z}$ are the d-orbital splittings in $\left[\mathrm{Fe}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{3+}$ and $\left[\mathrm{Ni}(\mathrm{Cl})_4\right]^{2-}$ complex ions respectively.

In the light of the above statements, choose the correct answer from the options given below :

Both Statement I and Statement II are correct

Both Statement I and Statement II are incorrect

Statement I is correct but Statement II is incorrect

Statement I is incorrect but Statement II is correct

Question 19: Palette 19/274

JEE Mains 2026 MCQ

Identify the correct statements from the following

A. $\left[\mathrm{Fe}\left(\mathrm{C}_2 \mathrm{O}_4\right)_3\right]^{3-}$ is the most stable complex among $\left[\mathrm{Fe}(\mathrm{OH})_6\right]^{3-},\left[\mathrm{Fe}\left(\mathrm{C}_2 \mathrm{O}_4\right)_3\right]^{3-}$ and $\left[\mathrm{Fe}(\mathrm{SCN})_6\right]^{3-}$

B. The stability of $\left[\mathrm{Cu}\left(\mathrm{NH}_3\right)_4\right]^{2+}$ is greater than that of $\left[\mathrm{Cu}(\mathrm{en})_2\right]^{2+}$

C. The hybridization of Fe in $\mathrm{K}_4\left[\mathrm{Fe}(\mathrm{CN})_6\right]$ is $\mathrm{d}^2 \mathrm{sp}^3$

D. $\left[\mathrm{Fe}\left(\mathrm{NO}_2\right)_3 \mathrm{Cl}_3\right]^{3-}$ exhibits linkage isomerism

E. $ \mathrm{NO}_2^{-}$and $\mathrm{SCN}^{-}$ligands are NOT ambidentate ligands

Choose the correct answer from the options given below :

A, B, C, D and E

B, C and D only

A, C and D only

A, C and E only

Question 20: Palette 20/274

JEE Mains 2026 MCQ

The correct statements about metal carbonyls are

A. The metal-carbon bonds in metal carbonyls possess both $\sigma$ and $\pi$ character.

B. Due to synergic bonding interactions between metal and CO ligand, the metal-carbon bond becomes weak.

C. The metal-carbon $\sigma$ bond is formed by the donation of lone pair of electrons on the carbonyl carbon into a vacant orbital of metal.

D. The metal-carbon $\pi$ bond is formed by the donation of electrons from filled d-orbital of metal into vacant $\pi^*$ orbital of CO .

Choose the correct answer from the options given below :

A and B Only

A, C and D Only

B and C Only

A and D Only

Question 21: Palette 21/274

JEE Mains 2026 MCQ

Given below are two statements:

Statement I: Each electron in $\mathrm{e}_{\mathrm{g}}$ orbitals destabilizes the orbitals by $+0.6 \Delta_{\mathrm{o}}$ and each electron in the $t_{2 g}$ orbitals stabilizes the orbitals by $-0.4 \Delta_0$ in an octahedral field on the basis of crystal field theory.

Statement II: All the d - orbitals of the transition metals have the same energy in their free atomic state but when a complex is formed the ligands destroy the degeneracy of these orbitals on the basis of crystal field theory.

In the light of the above statements, choose the correct answer from the options given below

Both Statement I and Statement II are correct

Both Statement I and Statement II are incorrect

Statement I is correct but Statement II is incorrect

Statement I is incorrect but Statement II is correct

Question 22: Palette 22/274

JEE Mains 2026 MCQ

Consider the metal complexes $\left[\mathrm{Ni}(\mathrm{en})_3\right]^{2+}(\mathrm{A}),\left[\mathrm{NiCl}_4\right]^{2-}(\mathrm{B})$ and $\left[\mathrm{Ni}\left(\mathrm{NH}_3\right)_6\right]^{2+}(\mathrm{C})$. Choose the CORRECT option by considering the number of unpaired electrons present in (A), (B) and (C) respectively and the order of frequency of absorption.

2, 2, 2 and $(\mathrm{A})>(\mathrm{C})>(\mathrm{B})$

0, 2, 0 and $(\mathrm{A})>(\mathrm{C})>(\mathrm{B})$

2, 2, 0 and $(\mathrm{B})>(\mathrm{C})>(\mathrm{A})$

2, 2, 2 and $(\mathrm{C})>(\mathrm{A})>(\mathrm{B})$

Question 23: Palette 23/274

JEE Mains 2026 MCQ

$ \text { Match the LIST-I with LIST-II } $

List-I Complex ion		List-II Calculated spin only magnetic moment (BM)
A.	$ \left[\mathrm{Cr}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+} $	I.	3.87
B.	$ \left[\mathrm{Co}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+} $	II.	5.92
C.	$ \left[\mathrm{Cu}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+} $	III.	4.90
D.	$ \left[\mathrm{Mn}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+} $	IV.	1.73

Choose the correct answer from the options given below :

A-I, B-III, C-IV, D-II

A-II, B-I, C-III, D-IV

A-IV, B-II, C-I, D-III

A-III, B-I, C-IV, D-II

Question 24: Palette 24/274

JEE Mains 2026 MCQ

Given below are two statements :

Statement I : Among Zn, Mn, Sc and Cu, the energy required to remove the third valence electron is highest for Zn and lowest for Sc.

Statement II : The correct order of the following complexes in terms of CFSE is $[\text{Co(H}_2\text{O})_6]^{2+} < [\text{Co(H}_2\text{O})_6]^{3+} < [\text{Co(en)}_3]^{3+}$.

In the light of the above statements, choose the correct answer from the options given below :

Both Statement I and Statement II are true

Both Statement I and Statement II are false

Statement I is true but Statement II is false

Statement I is false but Statement II is true

Question 25: Palette 25/274

JEE Mains 2026 MCQ

Which of the following complexes will show coordination isomerism?

A. $[\mathrm{Ag(NH}_3)_2][\mathrm{Ag(CN)}_2]$

B. $[\mathrm{Co(NH}_3)_6][\mathrm{Cr(CN)}_6]$

C. $[\mathrm{Co(NH}_3)_6][\mathrm{Co(CN)}_6]$

D. $[\mathrm{Fe(NH}_3)_6][\mathrm{Co(CN)}_6]$

E. $[\mathrm{Co(NH}_3)_6][\mathrm{Fe(CN)}_6]$

Choose the correct answer from the options given below:

B, C and D Only

B, D and E Only

A, C and D Only

C, D and E Only

Question 26: Palette 26/274

JEE Mains 2026 MCQ

Match List - I with List - II.

	List - I Chromium (III) Complexes (en = ethylene diamine)	List - II Δ₀ (cm⁻¹)
A	[Cr(CN)₆]³⁻	I. 15,060
B	[CrF₆]³⁻	II. 17,400
C	[Cr(H₂O)₆]³⁺	III. 22,300
D	[Cr(en)₃]³⁺	IV. 26,600

Choose the correct answer from the options given below:

A-I, B-II, C-III, D-IV

A-II, B-III, C-IV, D-I

A-III, B-IV, C-I, D-II

A-IV, B-I, C-II, D-III

Question 27: Palette 27/274

JEE Mains 2025 MCQ

Match the LIST-I with LIST-II

LIST-I (Complex/ Species)	LIST-II (Shape & magnetic moment)
A. [Ni(CO)₄]	I. Tetrahedral, 2.8 BM
B. [Ni(CN)₄]^2–	II. Square planar, 0 BM
C. [NiCl₄]^2–	III. Tetrahedral, 0 BM
D. [MnBr₄]^2–	IV. Tetrahedral, 5.9 BM

Choose the correct answer from the options given below:

A-I, B-II, C-III, D-IV

A-IV, B-I, C-III, D-II

A-III, B-II, C-I, D-IV

A-III, B-IV, C-II, D-I

Question 28: Palette 28/274

JEE Mains 2025 MCQ

The number of species from the following that are involved in sp³d² hybridization is :

[Co(NH₃)₆]³⁺, SF₆, [CrF₆]³⁻, [CoF₆]³⁻, [Mn(CN)₆]³⁻, and [MnCl₆]³⁻

Question 29: Palette 29/274

JEE Mains 2025 MCQ

Given below are two statements:

Statement I: A homoleptic octahedral complex, formed using monodentate ligands, will not show stereoisomerism.

Statement II: cis- and trans- platin are heteroleptic complexes of Pd.

In the light of the above statements, choose the correct answer from the options given below:

Statement I is true but Statement II is false

Both Statement I and Statement II are true

Both Statement I and Statement II are false

Statement I is false but Statement II is true

Question 30: Palette 30/274

JEE Mains 2025 MCQ

Match List - I with List - II.

List - I (Complex)	List - II (Primary valency and Secondary valency)
(A) [Co(en)₂Cl₂]Cl	(I) 3, 6
(B) [Pt(NH₃)₂Cl(NO₂)]	(II) 3, 4
(C) Hg [Co(SCN)₄]	(III) 2, 6
(D) [Mg (EDTA)]²⁻	(IV) 2, 4

Choose the correct answer from the options given below :

(A)-(I), (B)-(III), (C)-(II), (D)-(IV)

(A)-(II), (B)-(III), (C)-(IV), (D)-(I)

(A)-(I), (B)-(IV), (C)-(II), (D)-(III)

(A)-(III), (B)-(I), (C)-(II), (D)-(IV)

Question 31: Palette 31/274

JEE Mains 2025 MCQ

The number of unpaired electrons responsible for the paramagnetic nature of the following complex species are respectively :

[Fe(CN)₆]³⁻, [FeF₆]³⁻, [CoF₆]³⁻, [Mn(CN)₆]³⁻

1, 5, 4, 2

1, 4, 4, 2

1, 5, 5, 2

1, 1, 4, 2

Question 32: Palette 32/274

JEE Mains 2025 MCQ

'X' is the number of acidic oxides among VO₂, V₂O₃, CrO₃, V₂O₅ and Mn₂O₇. The primary valency of cobalt in
[Co(H₂NCH₂CH₂NH₂)₃]₂(SO₄)₃ is Y. The value of X + Y is _________.

Question 33: Palette 33/274

JEE Mains 2025 MCQ

An octahedral complex having molecular composition $\mathrm{Co} \cdot 5 \mathrm{NH}_3 \cdot \mathrm{Cl}^2 . \mathrm{SO}_4$ has two isomers A and B. The solution of A gives a white precipitate with $\mathrm{AgNO}_3$ solution and the solution of B gives white precipitate with $\mathrm{BaCl}_2$ solution. The type of isomerism exhibited by the complex is,

Co-ordinate isomerism

Ionisation isomerism

Geometrical isomerism

Linkage isomerism

Question 34: Palette 34/274

JEE Mains 2025 MCQ

' $X$ ' is the number of electrons in $t_{2 g}$ orbitals of the most stable complex ion among $\left[\mathrm{Fe}\left(\mathrm{NH}_3\right)_6\right]^{3+},\left[\mathrm{FeCl}_6\right]^{3-}, \quad\left[\mathrm{Fe}\left(\mathrm{C}_2 \mathrm{O}_4\right)_3\right]^{3-}$ and $\left[\mathrm{Fe}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{3+}$. The nature of oxide of vanadium of the type $\mathrm{V}_2 \mathrm{O}_{\mathrm{X}}$ is :

Amphoteric

Acidic

Basic

Neutral

Question 35: Palette 35/274

JEE Mains 2025 MCQ

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

$\left[\mathrm{CoF}_6\right]^{3-}>\left[\mathrm{FeF}_6\right]^{3-}>\left[\mathrm{Ni}(\mathrm{CO})_4\right]>\left[\mathrm{Ni}(\mathrm{CN})_4\right]^{2-}$

$\left[\mathrm{FeF}_6\right]^{3-}>\left[\mathrm{CoF}_6\right]^{3-}>\left[\mathrm{Ni}(\mathrm{CN})_4\right]^{2-}>\left[\mathrm{Ni}(\mathrm{CO})_4\right]$

$\left[\mathrm{FeF}_6\right]^{3-}>\left[\mathrm{CoF}_6\right]^{3-}>\left[\mathrm{Ni}(\mathrm{CN})_4\right]^{2-}=\left[\mathrm{Ni}(\mathrm{CO})_4\right]$

$\left[\mathrm{Ni}(\mathrm{CN})_4\right]^{2-}>\left[\mathrm{FeF}_6\right]^{3-}>\left[\mathrm{CoF}_6\right]^{3-}>\left[\mathrm{Ni}(\mathrm{CO})_4\right]$

Question 36: Palette 36/274

JEE Mains 2025 MCQ

Which one of the following complexes will have $\Delta_{\mathrm{o}}=0$ and $\mu=5.96$ B.M?

$\left[\mathrm{FeF}_6\right]^{4-}$

$\left[\mathrm{Mn}(\mathrm{SCN})_6\right]^{4-}$

$\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_6\right]^{3+}$

$\left[\mathrm{Fe}(\mathrm{CN})_6\right]^{4-}$

Question 37: Palette 37/274

JEE Mains 2025 MCQ

Number of stereoisomers possible for the complexes, $\left[\mathrm{CrCl}_3(\mathrm{py})_3\right]$ and $\left[\mathrm{CrCl}_2(\mathrm{ox})_2\right]^{3-}$ are respectively $(p y=$ pyridine,$o x=$ oxalate $)$

3 & 3

2 & 3

1 & 2

2 & 2

Question 38: Palette 38/274

JEE Mains 2025 MCQ

Identify the diamagnetic octahedral complex ions from below ;

A. $\left[\mathrm{Mn}(\mathrm{CN})_6\right]^{3-}$

B. $\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_6\right]^{3+}$

C. $\left[\mathrm{Fe}(\mathrm{CN})_6\right]^{4-}$

D. $\left[\mathrm{Co}\left(\mathrm{H}_2 \mathrm{O}\right)_3 \mathrm{~F}_3\right]$

Choose the correct answer from the options given below:

B and C Only

A and C Only

B and D Only

A and D Only

Question 39: Palette 39/274

JEE Mains 2025 MCQ

The correct order of the complexes $\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_5\left(\mathrm{H}_2 \mathrm{O}\right)\right]^{3+}(\mathrm{A}),\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_6\right]^{3+}(\mathrm{B}),\left[\mathrm{Co}(\mathrm{CN})_6\right]^{3-}(\mathrm{C})$ and $\left[\mathrm{CoCl}\left(\mathrm{NH}_3\right)_5\right]^{2+}(\mathrm{D})$ in terms of wavelength of light absorbed is

$\mathrm{D}>\mathrm{C}>\mathrm{B}>\mathrm{A}$

$\mathrm{C}>\mathrm{B}>\mathrm{A}>\mathrm{D}$

$\mathrm{D}>\mathrm{A}>\mathrm{B}>\mathrm{C}$

$\mathrm{C}>\mathrm{B}>\mathrm{D}>\mathrm{A}$

Question 40: Palette 40/274

JEE Mains 2025 MCQ

$ \text { Match the LIST-I with LIST-II } $

LIST-I (Molecules/ion)		LIST-II (Hybridisation of central atom)
A.	$ \mathrm{PF}_5 $	I	$ \mathrm{dsp}^2 $
B	$ \mathrm{SF}_6 $	II	$ \mathrm{sp}^3 \mathrm{~d} $
C	$ \mathrm{Ni}(\mathrm{CO})_4 $	III	$ \mathrm{sp}^3 \mathrm{~d}^2 $
D	$ \left[\mathrm{PtCl}_4\right]^{2-} $	IV	$ \mathrm{sp}^3 $

$ \text { Choose the correct answer from the options given below: } $

A-IV, B-I, C-II, D-III

A-III, B-I, C-IV, D-II

A-II, B-III, C-IV, D-I

A-I, B-II, C-III, D-IV

Question 41: Palette 41/274

JEE Mains 2025 MCQ

The type of hybridization and the magnetic property of $\left[\mathrm{MnCl}_6\right]^{3-}$ are,

$s p^3 d^2$, paramagnetic with four unpaired electrons.

$d^2 s p^3$, paramagnetic with four unpaired electrons.

$\mathrm{sp}^3 \mathrm{~d}^2$, paramagnetic with two unpaired electrons.

$\mathrm{d}^2 \mathrm{sp}^3$, paramagnetic with two unpaired electrons.

Question 42: Palette 42/274

JEE Mains 2025 MCQ

The d-orbital electronic configuration of the complex among $\left[\mathrm{Co}(\mathrm{en})_3\right]^{3+},\left[\mathrm{CoF}_6\right]^{3-}$, $\left[\mathrm{Mn}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+}$ and $\left[\mathrm{Zn}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+}$ that has the highest CFSE is :

$t_{2 g}{ }^6 e_g^0$

$t_{2 g}{ }^3 e_g^2$

$\mathrm{t}_{2 \mathrm{~g}}{ }^4 \mathrm{e}_{\mathrm{g}}{ }^2$

$t_{2 g}{ }^6 e_g^4$

Question 43: Palette 43/274

JEE Mains 2025 MCQ

Given below are two statements :

Statement (I) : In octahedral complexes, when $\Delta_0<\mathrm{P}$ high spin complexes are formed. When $\Delta_0>P$ low spin complexes are formed.

Statement (II) : In tetrahedral complexes because of $\Delta_t < P$, low spin complexes are rarely formed.

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

Both Statement I and Statement II are incorrect

Statement I is correct but Statement II is incorrect

Statement I is incorrect but Statement II is correct

Both Statement I and Statement II are correct

Question 44: Palette 44/274

JEE Mains 2025 MCQ

Identify the homoleptic complexes with odd number of $d$ electrons in the central metal :

(A) $\left[\mathrm{FeO}_4\right]^{2-}$

(B) $\left[\mathrm{Fe}(\mathrm{CN})_6\right]^{3-}$

(D) $\left[\mathrm{CoCl}_4\right]^{2-}$

(E) $\left[\mathrm{Co}\left(\mathrm{H}_2 \mathrm{O}\right)_3 \mathrm{~F}_3\right]$

Choose the correct answer from the options given below :

(A), (B) and (D) only

(B) and (D) only

(A), (C) and (E) only

Question 45: Palette 45/274

JEE Mains 2025 MCQ

The calculated spin-only magnetic moments of $K_3[Fe(OH)_6]$ and $K_4[Fe(OH)_6]$ respectively are :

4.90 and 4.90 B.M.

4.90 and 5.92 B.M.

5.92 and 4.90 B.M.

3.87 and 4.90 B.M.

Question 46: Palette 46/274

JEE Mains 2025 MCQ

The correct increasing order of stability of the complexes based on $\Delta_0$ value is :

I. $[\text{Mn}(\text{CN})_6]^{3-}$

II. $[\text{Co}(\text{CN})_6]^{4-}$

III. $[\text{Fe}(\text{CN})_6]^{4-}$

IV. $[\text{Fe}(\text{CN})_6]^{3-}$

I < II < IV < III

IV < III < II < I

III < II < IV < I

II < III < I < IV

Question 47: Palette 47/274

JEE Mains 2025 MCQ

Match List - I with List - II.

List - I (Complex)	List - II (Hybridisation & Magnetic characters)
(A) [MnBr₄]^2-	(I) d²sp³ & diamagnetic
(B) [FeF₆]^3-	(II) sp³d² & paramagnetic
(C) [Co(C₂O₄)₃]^3-	(III) sp³ & diamagnetic
(D) [Ni(CO)₄]	(IV) sp³ & paramagnetic

Choose the correct answer from the options given below :

(A)-(III), (B)-(I), (C)-(I), (D)-(IV)

(A)-(III), (B)-(II), (C)-(III), (D)-(IV)

(A)-(IV), (B)-(II), (C)-(I), (D)-(III)

(A)-(IV), (B)-(I), (C)-(II), (D)-(III)

Question 48: Palette 48/274

JEE Mains 2025 MCQ

Match List - I with List - II.

List - I (Complex)	List - II (Hybridisation of central metal ion)
(A) [CoF₆]^3-	(I) d²sp³
(B) [NiCl₄]^2-	(II) sp³
(C) [Co(NH₃)₆]³⁺	(III) sp³d²
(D) [Ni(CN)₄]^2-	(IV) dsp²

Choose the correct answer from the options given below:

(A)-(I), (B)-(II), (C)-(III), (D)-(IV)

(A)-(III), (B)-(IV), (C)-(I), (D)-(II)

(A)-(I), (B)-(IV), (C)-(III), (D)-(II)

(A)-(III), (B)-(II), (C)-(I), (D)-(IV)

Question 49: Palette 49/274

JEE Mains 2025 MCQ

The conditions and consequence that favours the $t_{2 \mathrm{~g}}{ }^3 \mathrm{e}_{\mathrm{g}}{ }^1$ configuration in a metal complex are :

strong field ligand, low spin complex

strong field ligand, high spin complex

weak field ligand, high spin complex

weak field ligand, low spin complex

Question 50: Palette 50/274

JEE Mains 2025 MCQ

When Ethane-1,2-diamine is added progressively to an aqueous solution of Nickel (II) chloride, the sequence of colour change observed will be:

Pale Blue $\rightarrow$ Blue $\rightarrow$ Green $\rightarrow$ Violet

Pale Blue $\rightarrow$ Blue $\rightarrow$ Violet $\rightarrow$ Green

Green $\rightarrow$ Pale Blue $\rightarrow$ Blue $\rightarrow$ Violet

Violet $\rightarrow$ Blue $\rightarrow$ Pale Blue $\rightarrow$ Green

Question 51: Palette 51/274

JEE Mains 2025 MCQ

One mole of the octahedral complex compound $\mathrm{Co}\left(\mathrm{NH}_3\right)_5 \mathrm{Cl}_3$ gives 3 moles of ions on dissolution in water. One mole of the same complex reacts with excess of $\mathrm{AgNO}_3$ solution to yield two moles of $\mathrm{AgCl}_{(\mathrm{s})}$. The structure of the complex is:

$\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_5 \mathrm{Cl}\right] \mathrm{Cl}_2$

$\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_4 \mathrm{Cl}\right] \cdot \mathrm{Cl}_2 \cdot \mathrm{NH}_3$

$\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_3 \mathrm{Cl}_3\right] \cdot 2 \mathrm{NH}_3$

$\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_4 \mathrm{Cl}_2\right] \cdot \mathrm{Cl} \cdot \mathrm{NH}_3$

Question 52: Palette 52/274

JEE Mains 2025 MCQ

Identify the coordination complexes in which the central metal ion has $\mathrm{d}^4$ configuration.

(A) $\left[\mathrm{FeO}_4\right]^{2-}$

(B) $\quad\left[\mathrm{Mn}(\mathrm{CN})_6\right]^{3-}$

(D) JEE Main 2025 (Online) 23rd January Evening Shift Chemistry - Coordination Compounds Question 63 English (E) $\left[\mathrm{NiF}_6\right]^{2-}$

Choose the correct answer from the options given below :

(B), (C) and (D) only

$(A),(B)$ and $(E)$ only

(B) and (D) only

Question 53: Palette 53/274

JEE Mains 2025 MCQ

$\mathrm{CrCl}_3 \cdot \mathrm{xNH}_3$ can exist as a complex. 0.1 molal aqueous solution of this complex shows a depression in freezing point of $0.558^{\circ} \mathrm{C}$. Assuming $100 \%$ ionisation of this complex and coordination number of Cr is 6 , the complex will be (Given $\mathrm{K}_{\mathrm{f}}=1.86 \mathrm{~K} \mathrm{~kg} \mathrm{~mol}^{-1}$ )

$\left[\mathrm{Cr}\left(\mathrm{NH}_3\right)_5 \mathrm{Cl}\right] \mathrm{Cl}_2$

$\left[\mathrm{Cr}\left(\mathrm{NH}_3\right)_4 \mathrm{Cl}_2\right] \mathrm{Cl}$

$\left[\mathrm{Cr}\left(\mathrm{NH}_3\right)_6\right] \mathrm{Cl}_3$

$\left[\mathrm{Cr}\left(\mathrm{NH}_3\right)_3 \mathrm{Cl}_3\right]$

Question 54: Palette 54/274

JEE Mains 2025 MCQ

The d-electronic configuration of an octahedral Co (II) complex having magnetic moment of 3.95 BM is:

$e^4 t_2^3$

$\mathrm{t}_{2 \mathrm{~g}}{ }^6 \mathrm{e}_{\mathrm{g}}{ }^1$

$\mathrm{t}_{2 \mathrm{~g}}{ }^5 \mathrm{e}_{\mathrm{g}}{ }^2$

$t_{2 g^3}^3 e_g^0$

Question 55: Palette 55/274

JEE Mains 2025 MCQ

The complex that shows Facial - Meridional isomerism is :

$\left[\mathrm{Co}(\mathrm{en})_2 \mathrm{Cl}_2\right]^{+}$

$\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_3 \mathrm{Cl}_3\right]$

$\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_4 \mathrm{Cl}_2\right]^{+}$

$\left[\mathrm{Co}(\mathrm{en})_3\right]^{3+}$

Question 56: Palette 56/274

JEE Mains 2025 MCQ

The correct order of the following complexes in terms of their crystal field stabilization energies is :

$\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_4\right]^{2+}<\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_6\right]^{2+}<\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_6\right]^{3+}<\left[\mathrm{Co}(\mathrm{en})_3\right]^{3+}$

$\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_4\right]^{2+}<\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_6\right]^{2+}<\left[\mathrm{Co}(\mathrm{en})_3\right]^{3+}<\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_6\right]^{3+}$

$\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_6\right]^{2+}<\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_6\right]^{3+}<\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_4\right]^{2+}<\left[\mathrm{Co}(\mathrm{en})_3\right]^{3+}$

$\left[\mathrm{Co}(\mathrm{en})_3\right]^{3+}<\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_6\right]^{3+}<\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_6\right]^{2+}<\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_4\right]^{2+}$

Question 57: Palette 57/274

JEE Mains 2025 MCQ

Identify the homoleptic complex(es) that is/are low spin.

(A) $\left[\mathrm{Fe}(\mathrm{CN})_5 \mathrm{NO}\right]^{2-}$

(B) $\left[\mathrm{CoF}_6\right]^{3-}$

(D) $\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_6\right]^{3+}$

(E) $\left[\mathrm{Cr}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+}$

Choose the correct answer from the options given below :

(A) and (C) only

(B) and (E) only

Question 58: Palette 58/274

JEE Mains 2025 MCQ

From the magnetic behaviour of $\left[\mathrm{NiCl}_4\right]^{2-}$ (paramagnetic) and $\left[\mathrm{Ni}(\mathrm{CO})_4\right]$ (diamagnetic), choose the correct geometry and oxidation state.

$\left[\mathrm{NiCl}_4\right]^{2-}: \mathrm{Ni}(0)$, tetrahedral $\left[\mathrm{Ni}(\mathrm{CO})_4\right]: \mathrm{Ni}(0)$, square planar

$\left[\mathrm{NiCl}_4\right]^{2-}: \mathrm{Ni}^{\mathrm{II}}$, tetrahedral $\left[\mathrm{Ni}(\mathrm{CO})_4\right]: \mathrm{Ni}(0)$, tetrahedral

$\left[\mathrm{NiCl}_4\right]^{2-}: \mathrm{Ni}^{\mathrm{II}}$, tetrahedral $\left[\mathrm{Ni}(\mathrm{CO})_4\right]: \mathrm{Ni}^{I I}$, square planar

$\left[\mathrm{NiCl}_4\right]^{2-}: \mathrm{Ni}^{\mathrm{II}}$, square planar $\left[\mathrm{Ni}(\mathrm{CO})_4\right]: \mathrm{Ni}(0)$, square planar

Question 59: Palette 59/274

JEE Mains 2025 MCQ

In which of the following complexes the CFSE, $\Delta_o$ will be equal to zero?

$\mathrm{K}_3\left[\mathrm{Fe}(\mathrm{SCN})_6\right]$

$\left[\mathrm{Fe}(\mathrm{en})_3\right] \mathrm{Cl}_3$

$\left[\mathrm{Fe}\left(\mathrm{NH}_3\right)_6\right] \mathrm{Br}_2$

$\mathrm{K}_4\left[\mathrm{Fe}(\mathrm{CN})_6\right]$

Question 60: Palette 60/274

JEE Mains 2024 MCQ

Match List I with List II

	LIST I		LIST II
A.	$\mathrm{K}_2\left[\mathrm{Ni}(\mathrm{CN})_4\right]$	I.	$sp^3$
B.	$\left[\mathrm{Ni}(\mathrm{CO})_4\right]$	II.	$sp^3d^2$
C.	$\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_6\right] \mathrm{Cl}_3$	III.	$dsp^2$
D.	$\mathrm{Na}_3\left[\mathrm{CoF}_6\right]$	IV.	$d^2sp^3$

Choose the correct answer from the options given below:

A-III, B-II, C-IV, D-I

A-III, B-I, C-II, D-IV

A-I, B-III, C-II, D-IV

A-III, B-I, C-IV, D-II

Question 61: Palette 61/274

JEE Mains 2024 MCQ

The coordination environment of $\mathrm{Ca}^{2+}$ ion in its complex with $\mathrm{EDTA}^{4-}$ is :

trigonal prismatic

octahedral

square planar

tetrahedral

Question 62: Palette 62/274

JEE Mains 2024 MCQ

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).

Assertion (A): The total number of geometrical isomers shown by $[\mathrm{Co}(\mathrm{en})_2 \mathrm{Cl}_2]^{+}$ complex ion is three.

Reason (R): $[\mathrm{Co}(\mathrm{en})_2 \mathrm{Cl}_2]^{+}$ complex ion has an octahedral geometry.

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

(A) is correct but (R) is not correct

(A) is not correct but (R) is correct

Both (A) and (R) are correct but (R) is not the correct explanation of (A)

Both (A) and (R) are correct and (R) is the correct explanation of (A)

Question 63: Palette 63/274

JEE Mains 2024 MCQ

Match List I with List II

	LIST I (Complex ion)		LIST II (Spin only magnetic moment in B.M.)
A.	$ \left[\mathrm{Cr}\left(\mathrm{NH}_3\right)_6\right]^{3+} $	I.	4.90
B.	$ \left[\mathrm{NiCl}_4\right]^{2-} $	II.	3.87
C.	$ \left[\mathrm{CoF}_6\right]^{3-} $	III.	0.0
D.	$ \left[\mathrm{Ni}(\mathrm{CN})_4\right]^{2-} $	IV.	2.83

Choose the correct answer from the options given below :

(A)-(IV), (B)-(III), (C)-(I), (D)-(II)

(A)-(II), (B)-(III), (C)-(I), (D)-(IV)

(A)-(I), (B)-(IV), (C)-(II), (D)-(III)

(A)-(II), (B)-(IV), (C)-(I), (D)-(III)

Question 64: Palette 64/274

JEE Mains 2024 MCQ

Number of Complexes with even number of electrons in $\mathrm{t_{2 g}}$ orbitals is -

$\left[\mathrm{Fe}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+},\left[\mathrm{Co}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+},\left[\mathrm{Co}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{3+},\left[\mathrm{Cu}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+},\left[\mathrm{Cr}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+}$

Question 65: Palette 65/274

JEE Mains 2024 MCQ

An octahedral complex with the formula $\mathrm{CoCl}_3 \cdot \mathrm{nNH}_3$ upon reaction with excess of $\mathrm{AgNO}_3$ solution gives 2 moles of $\mathrm{AgCl}$. Consider the oxidation state of $\mathrm{Co}$ in the complex is '$x$'. The value of "$x+n$" is __________.

Question 66: Palette 66/274

JEE Mains 2024 MCQ

Given below are two statements:

Statement I: $\mathrm{N}\left(\mathrm{CH}_3\right)_3$ and $\mathrm{P}\left(\mathrm{CH}_3\right)_3$ can act as ligands to form transition metal complexes.

Statement II: As N and P are from same group, the nature of bonding of $\mathrm{N}\left(\mathrm{CH}_3\right)_3$ and $\mathrm{P}\left(\mathrm{CH}_3\right)_3$ is always same with transition metals.

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

Both Statement I and Statement II are incorrect.

Both Statement I and Statement II are correct.

Statement I is incorrect but Statement II is correct.

Statement I is correct but Statement II is incorrect.

Question 67: Palette 67/274

JEE Mains 2024 MCQ

Match List I with List II

	LIST I (Compound)		LIST II (Colour]
A.	$\mathrm{Fe}_4\left[\mathrm{Fe}(\mathrm{CN})_6\right]_3 \cdot \mathrm{xH_2O}$	I.	Violet
B.	$\left[\mathrm{Fe}(\mathrm{CN})_5 \mathrm{NOS}\right]^{4-}$	II.	Blood Red
C.	$[\mathrm{Fe}(\mathrm{SCN})]^{2+}$	III.	Prussian Blue
D.	$\left(\mathrm{NH}_4\right)_3 \mathrm{PO}_4\cdot12 \mathrm{MoO}_3$	IV.	Yellow

Choose the correct answer from the options given below:

A-IV, B-I, C-II, D-III

A-I, B-II, C-III, D-IV

A-II, B-III, C-IV, D-I

A-III, B-I, C-II, D-IV

Question 68: Palette 68/274

JEE Mains 2024 MCQ

Given below are two statements :

Statement I : $\mathrm{PF}_5$ and $\mathrm{BrF}_5$ both exhibit $\mathrm{sp}^3 \mathrm{~d}$ hybridisation.

Statement II : Both $\mathrm{SF}_6$ and $[\mathrm{Co}(\mathrm{NH}_3)_6]^{3+}$ exhibit $\mathrm{sp}^3 \mathrm{~d}^2$ hybridisation.

In the light of the above statements, choose the correct answer from the options given below :

Both Statement I and Statement II are false

Statement I is true but Statement II is false

Statement I is false but Statement II is true

Both Statement I and Statement II are true

Question 69: Palette 69/274

JEE Mains 2024 MCQ

Match List I with List II.

	LIST I Tetrahedral Complex		LIST II Electronic configuration
A.	$ \mathrm{TiCl}_4 $	I.	$ \mathrm{e}^2, \mathrm{t}_2^0 $
B.	$ \left[\mathrm{FeO}_4\right]^{2-} $	II.	$ \mathrm{e^4, t_2^3} $
C.	$ \left[\mathrm{FeCl}_4\right]^{-} $	III.	$ \mathrm{e}^0, \mathrm{t}_2^0 $
D.	$ \left[\mathrm{CoCl}_4\right]^{2-} $	IV.	$ \mathrm{e}^2, \mathrm{t}_2^3 $

Choose the correct answer from the options given below :

(A)-(IV), (B)-(III), (C)-(I), (D)-(II)

(A)-(III), (B)-(I), (C)-(IV), (D)-(II)

(A)-(I), (B)-(III), (C)-(IV), (D)-(II)

(A)-(III), (B)-(IV), (C)-(II), (D)-(I)

Question 70: Palette 70/274

JEE Mains 2024 MCQ

The correct IUPAC name of $[\mathrm{PtBr}_2(\mathrm{PMe}_3)_2]$ is :

bis(trimethylphosphine)dibromoplatinum(II)

dibromodi(trimethylphosphine)platinum(II)

dibromobis(trimethylphosphine)platinum(II)

bis[bromo(trimethylphosphine)]platinum(II)

Question 71: Palette 71/274

JEE Mains 2024 MCQ

Consider the following complexes

(A) $\left[\mathrm{CoCl}\left(\mathrm{NH}_3\right)_5\right]^{2+}$, (B) $\left[\mathrm{Co}(\mathrm{CN})_6\right]^{3-}$, (C) $ \left[\mathrm{Co}\left(\mathrm{NH}_3\right)_5\left(\mathrm{H}_2 \mathrm{O}\right)\right]^{3+} $, (D) $\left[\mathrm{Cu}\left(\mathrm{H}_2 \mathrm{O}\right)_4\right]^{2+}$

The correct order of A, B, C and D in terms of wavenumber of light absorbed is :

D < A < C < B

B < C < A < D

C < D < A < B

A < C < B < D

Question 72: Palette 72/274

JEE Mains 2024 MCQ

Match List I with List II

	LIST I (Hybridization)		LIST II (Orientation in Shape)
A.	sp$^3$	I.	Trigonal bipyramidal
B.	dsp$^2$	II.	Octahedral
C.	sp$^3$d	III.	Tetrahedral
D.	sp$^3$d$^2$	IV.	Square planar

Choose the correct answer from the options given below:

A-III, B-I, C-IV, D-II

A-III, B-IV, C-I, D-II

A-IV, B-III, C-I, D-II

A-II, B-I, C-IV, D-III

Question 73: Palette 73/274

JEE Mains 2024 MCQ

The number of complexes from the following with no electrons in the $t_2$ orbital is ______.

$\mathrm{TiCl}_4,\left[\mathrm{MnO}_4\right]^{-},\left[\mathrm{FeO}_4\right]^{2-},\left[\mathrm{FeCl}_4\right]^{-},\left[\mathrm{CoCl}_4\right]^{2-}$

Question 74: Palette 74/274

JEE Mains 2024 MCQ

The metal atom present in the complex MABXL (where A, B, X and L are unidentate ligands and $\mathrm{M}$ is metal) involves $\mathrm{sp}^3$ hybridization. The number of geometrical isomers exhibited by the complex is :

Question 75: Palette 75/274

JEE Mains 2024 MCQ

The correct order of ligands arranged in increasing field strength.

$\mathrm{F}^{-}<\mathrm{Br}^{-}<\mathrm{I}^{-}<\mathrm{NH}_3$

$\mathrm{H}_2 \mathrm{O}<\mathrm{^{-}OH}<\mathrm{CN}^{-}<\mathrm{NH}_3$

$\mathrm{Br}^{-}<\mathrm{F}^{-}<\mathrm{H}_2 \mathrm{O}<\mathrm{NH}_3$

$\mathrm{Cl}^{-}<\mathrm{^{-}OH}<\mathrm{Br}^{-}<\mathrm{CN}^{-}$

Question 76: Palette 76/274

JEE Mains 2024 MCQ

Which one of the following complexes will exhibit the least paramagnetic behaviour ? [Atomic number, $\mathrm{Cr}=24, \mathrm{Mn}=25, \mathrm{Fe}=26, \mathrm{Co}=27$]

$\left[\mathrm{Fe}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+}$

$\left[\mathrm{Mn}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+}$

$\left[\mathrm{Co}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+}$

$\left[\mathrm{Cr}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+}$

Question 77: Palette 77/274

JEE Mains 2024 MCQ

If an iron (III) complex with the formula $\left[\mathrm{Fe}\left(\mathrm{NH}_3\right)_x(\mathrm{CN})_y\right]^-$ has no electron in its $e_g$ orbital, then the value of $x+y$ is

Question 78: Palette 78/274

JEE Mains 2024 MCQ

The number of unpaired d-electrons in $\left[\mathrm{Co}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{3+}$ is ________.

Question 79: Palette 79/274

JEE Mains 2024 MCQ

A first row transition metal in its +2 oxidation state has a spin-only magnetic moment value of $3.86 \mathrm{~BM}$. The atomic number of the metal is

Question 80: Palette 80/274

JEE Mains 2024 MCQ

Number of complexes from the following with even number of unpaired "$\mathrm{d}$" electrons is ________ $[\mathrm{V}(\mathrm{H}_2 \mathrm{O})_6]^{3+},[\mathrm{Cr}(\mathrm{H}_2 \mathrm{O})_6]^{2+},[\mathrm{Fe}(\mathrm{H}_2 \mathrm{O})_6]^{3+},[\mathrm{Ni}(\mathrm{H}_2 \mathrm{O})_6]^{3+},[\mathrm{Cu}(\mathrm{H}_2 \mathrm{O})_6]^{2+}$ [Given atomic numbers: $\mathrm{V}=23, \mathrm{Cr}=24, \mathrm{Fe}=26, \mathrm{Ni}=28 \mathrm{Cu}=29$]

Question 81: Palette 81/274

JEE Mains 2024 MCQ

The correct sequence of ligands in the order of decreasing field strength is :

$\mathrm{NCS}^{-}>\mathrm{EDTA}^{4-}>\mathrm{CN}^{-}>\mathrm{CO}$

$\mathrm{CO}>\mathrm{H}_2 \mathrm{O}>\mathrm{F}^{-}>\mathrm{S}^{2-}$

$\mathrm{S}^{2-}>{ }^{-} \mathrm{OH}>\mathrm{EDTA}^{4-}>\mathrm{CO}$

${ }^{-} \mathrm{OH}>\mathrm{F}^{-}>\mathrm{NH}_3>\mathrm{CN}^{-}$

Question 82: Palette 82/274

JEE Mains 2024 MCQ

$\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_6\right]^{3+}$ and $\left[\mathrm{CoF}_6\right]^{3-}$ are respectively known as :

Inner orbital Complex, Spin paired Complex

Spin paired Complex, Spin free Complex

Spin free Complex, Spin paired Complex

Outer orbital Complex, Inner orbital Complex

Question 83: Palette 83/274

JEE Mains 2024 MCQ

Given below are two statements :

Statement (I) : Dimethyl glyoxime forms a six-membered covalent chelate when treated with $\mathrm{NiCl}_2$ solution in presence of $\mathrm{NH}_4 \mathrm{OH}$.

Statement (II) : Prussian blue precipitate contains iron both in $(+2)$ and $(+3)$ oxidation states.

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

Statement I is false but Statement II is true

Both Statement I and Statement II are true

Statement I is true but Statement II is false

Both Statement I and Statement II are false

Question 84: Palette 84/274

JEE Mains 2024 MCQ

Which of the following compounds show colour due to d-d transition?

$\mathrm{K}_2 \mathrm{Cr}_2 \mathrm{O}_7$

$\mathrm{CuSO}_4 \cdot 5 \mathrm{H}_2 \mathrm{O}$

$\mathrm{KMnO}_4$

$\mathrm{K}_2 \mathrm{CrO}_4$

Question 85: Palette 85/274

JEE Mains 2024 MCQ

Which of the following complex is homoleptic?

$\left[\mathrm{Ni}\left(\mathrm{NH}_3\right)_2 \mathrm{Cl}_2\right]$

$\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_4 \mathrm{Cl}_2\right]^{+}$

$\left[\mathrm{Fe}\left(\mathrm{NH}_3\right)_4 \mathrm{Cl}_2\right]^{+}$

$\left[\mathrm{Ni}(\mathrm{CN})_4\right]^{2-}$

Question 86: Palette 86/274

JEE Mains 2024 MCQ

Given below are two statements :

Statement (I) : A solution of $\left[\mathrm{Ni}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+}$ is green in colour.

Statement (II) : A solution of $\left[\mathrm{Ni}(\mathrm{CN})_4\right]^{2-}$ is colourless.

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

Statement I is incorrect but Statement II is correct

Both Statement I and Statement II are correct

Both Statement I and Statement II are incorrect

Statement I is correct but Statement II is incorrect

Question 87: Palette 87/274

JEE Mains 2024 MCQ

Select the option with correct property -

$\left[\mathrm{Ni}(\mathrm{CO})_4\right]$ and $\left[\mathrm{NiCl}_4\right]^{2-}$ both Paramagnetic

$\left[\mathrm{Ni}(\mathrm{CO})_4\right]$ and $\left[\mathrm{NiCl}_4\right]^{2-}$ both Diamagnetic

$\left[\mathrm{NiCl}_4\right]^{2-}$ Diamagnetic, $\left[\mathrm{Ni}(\mathrm{CO})_4\right]$ Paramagnetic

$\left[\mathrm{Ni}(\mathrm{CO})_4\right]$ Diamagnetic, $\left[\mathrm{NiCl}_4\right]^{2-}$ Paramagnetic

Question 88: Palette 88/274

JEE Mains 2024 MCQ

Match List I with List II

	List - I (Complex ion)		List - II (Electronic Configuration)
(A)	$\mathrm{[Cr(H_2O)_6]^{3+}}$	(I)	$t_{2 g}{ }^2 e_g^0$
(B)	$\left[\mathrm{Fe}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{3+}$	(II)	$t_{2 g}{ }^3 e_g{ }^0$
(C)	$\left[\mathrm{Ni}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+}$	(III)	$t_{2 g}{ }^3 e_g{ }^2$
(D)	$\left[\mathrm{V}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{3+}$	(IV)	$t_{2 g}{ }^6 e_g^2$

Choose the correct answer from the options given below:

A-IV, B-I, C-II, D-III

A-III, B-II, C-IV, D-I

A-II, B-III, C-IV, D-I

A-IV, B-III, C-I, D-II

Question 89: Palette 89/274

JEE Mains 2024 MCQ

The correct statements from following are:

A. The strength of anionic ligands can be explained by crystal field theory.

B. Valence bond theory does not give a quantitative interpretation of kinetic stability of coordination compounds.

C. The hybridization involved in formation of $\left[\mathrm{Ni}(\mathrm{CN})_4\right]^{2-}$ complex is $\mathrm{dsp}^2$.

D. The number of possible isomer(s) of cis- $\left[\mathrm{PtCl}_2(\mathrm{en})_2\right]^{2+}$ is one

Choose the correct answer from the options given below:

B, C only

B, D only

A, C only

A, D only

Question 90: Palette 90/274

JEE Mains 2024 MCQ

The coordination geometry around the manganese in decacarbonyldimanganese $(0)$ is

Trigonal bipyramidal

Square pyramidal

Square planar

Octahedral

Question 91: Palette 91/274

JEE Mains 2024 MCQ

Choose the correct statements from the following :

(A) Ethane-1, 2-diamine is a chelating ligand.

(B) Metallic aluminium is produced by electrolysis of aluminium oxide in presence of cryolite.

(D) Phosphine act as a ligand in Wilkinson catalyst.

(E) The stability constants of $\mathrm{Ca}^{2+}$ and $\mathrm{Mg}^{2+}$ are similar with EDTA complexes.

Choose the correct answer from the options given below :

(B), (C), (E) only

(A), (D), (E) only

(C), (D), (E) only

(A), (B), (C) only

Question 92: Palette 92/274

JEE Mains 2024 MCQ

A reagent which gives brilliant red precipitate with Nickel ions in basic medium is

dimethyl glyoxime

sodium nitroprusside

meta-dinitrobenzene

neutral $\mathrm{FeCl}_3$

Question 93: Palette 93/274

JEE Mains 2024 MCQ

Match List I with List II

	List - I (Substances)		List - II (Element Present)
(A)	Ziegler catalyst	(I)	Rhodium
(B)	Blood Pigment	(II)	Cobalt
(C)	Wilkinson catalyst	(III)	Iron
(D)	Vitamin $\mathrm{B_{12}}$	(IV)	Titanium

Choose the correct answer from the options given below:

A-IV, B-III, C-I, D-II

A-II, B-IV, C-I, D-III

A-III, B-II, C-IV, D-I

A-II, B-III, C-IV, D-I

Question 94: Palette 94/274

JEE Mains 2024 MCQ

In which one of the following metal carbonyls, $\mathrm{CO}$ forms a bridge between metal atoms?

$\left[\mathrm{Os}_3(\mathrm{CO})_{12}\right]$

$\left[\mathrm{Ru}_3(\mathrm{CO})_{12}\right]$

$\left[\mathrm{Mn}_2(\mathrm{CO})_{10}\right]$

$\left[\mathrm{Co}_2(\mathrm{CO})_8\right]$

Question 95: Palette 95/274

JEE Mains 2024 MCQ

Identity the incorrect pair from the following :

Haber process - Iron

Polythene preparation - $\mathrm{TiCl}_4, \mathrm{Al}\left(\mathrm{CH}_3\right)_3$

Photography - AgBr

Wacker process - $\mathrm{Pt} \mathrm{Cl}_2$

Question 96: Palette 96/274

JEE Mains 2024 MCQ

Identify from the following species in which $\mathrm{d}^2 \mathrm{sp}^3$ hybridization is shown by central atom :

$\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_6\right]^{3+}$

$\mathrm{SF}_6$

$\left[\mathrm{Pt}\left(\mathrm{Cl}_4\right)\right]^{2-}$

$\mathrm{BrF}_5$

Question 97: Palette 97/274

JEE Mains 2024 MCQ

Consider the following complex ions

$\begin{aligned} & \mathrm{P}=\left[\mathrm{FeF}_6\right]^{3-} \\ & \mathrm{Q}=\left[\mathrm{V}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+} \\ & \mathrm{R}=\left[\mathrm{Fe}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+} \end{aligned}$

The correct order of the complex ions, according to their spin only magnetic moment values (in B.M.) is :

R < Q < P

R < P < Q

Q < R < P

Q < P < R

Question 98: Palette 98/274

JEE Mains 2024 MCQ

Yellow compound of lead chromate gets dissolved on treatment with hot $\mathrm{NaOH}$ solution. The product of lead formed is a :

Tetraanionic complex with coordination number six

Neutral complex with coordination number four

Dianionic complex with coordination number six

Dianionic complex with coordination number four

Question 99: Palette 99/274

JEE Mains 2023 MCQ

The complex with highest magnitude of crystal field splitting energy $\left(\Delta_{0}\right)$ is :

$\left[\mathrm{Fe}\left(\mathrm{OH}_{2}\right)_{6}\right]^{3+}$

$\left[\mathrm{Mn}\left(\mathrm{OH}_{2}\right)_{6}\right]^{3+}$

$\left[\mathrm{Cr}\left(\mathrm{OH}_{2}\right)_{6}\right]^{3+}$

$\left[\mathrm{Ti}\left(\mathrm{OH}_{2}\right)_{6}\right]^{3+}$

Question 100: Palette 100/274

JEE Mains 2023 MCQ

The total number of stereoisomers for the complex $\left[\mathrm{Cr}(o x)_{2} \mathrm{ClBr}\right]^{3-}$ (where $o x=$ oxalate) is :

Question 101: Palette 101/274

JEE Mains 2023 MCQ

Which of the following complexes will exhibit maximum attraction to an applied magnetic field?

$\left[\mathrm{Ni}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{2+}$

$\left[\mathrm{Co}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{2+}$

$\left[\mathrm{Co}(\mathrm{en})_{3}\right]^{3+}$

$\left[\mathrm{Zn}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{2+}$

Question 102: Palette 102/274

JEE Mains 2023 MCQ

The mismatched combinations are

A. Chlorophyll - Co

B. Water hardness - EDTA

C. Photography $-\left[\mathrm{Ag}(\mathrm{CN})_{2}\right]^{-}$

D. Wilkinson catalyst $-\left[\left(\mathrm{Ph}_{3} \mathrm{P}\right)_{3} \mathrm{RhCl}\right]$

E. Chelating ligand - D-Penicillamine

Choose the correct answer from the options given below :

A and E Only

D and E Only

A and C Only

A, C, and E Only

Question 103: Palette 103/274

JEE Mains 2023 MCQ

Match List I with List II

	LIST I Complex		LIST II CFSE ($\Delta_0$)
A.	$\mathrm{[Cu(NH_3)_6]^{2+}}$	I.	$-0.6$
B.	$\mathrm{[Ti(H_2O)_6]^{3+}}$	II.	$-2.0$
C.	$\mathrm{[Fe(CN)_6]^{3-}}$	III.	$-1.2$
D.	$\mathrm{[NiF_6]^{4-}}$	IV.	$-0.4$

Choose the correct answer from the options given below:

A-I, B-IV, C-II, D-III

A-III, B-IV, C-I, D-II

A-II, B-III, C-I, D-IV

A-I, B-II, C-IV, D-III

Question 104: Palette 104/274

JEE Mains 2023 MCQ

Given below are two statements, one is labelled as Assertion A and the other is labelled as Reason R.

Assertion A : $\left[\mathrm{CoCl}\left(\mathrm{NH}_{3}\right)_{5}\right]^{2+}$ absorbs at lower wavelength of light with respect to $\left[\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{5}\left(\mathrm{H}_{2} \mathrm{O}\right)\right]^{3+}$

Reason R : It is because the wavelength of the light absorbed depends on the oxidation state of the metal ion.

In the light of the above statements, choose the correct answer from the options given below:

$\mathrm{A}$ is false but $\mathrm{R}$ is true

Both $\mathrm{A}$ and $\mathrm{R}$ are true but $\mathrm{R}$ is NOT the correct explanation of $A$

Both $\mathrm{A}$ and $\mathrm{R}$ are true and $\mathrm{R}$ is the correct explanation of $\mathrm{A}$

$\mathrm{A}$ is true but $\mathrm{R}$ is false

Question 105: Palette 105/274

JEE Mains 2023 MCQ

If $\mathrm{Ni}^{2+}$ is replaced by $\mathrm{Pt}^{2+}$ in the complex $\left[\mathrm{NiCl}_{2} \mathrm{Br}_{2}\right]^{2-}$, which of the following properties are expected to get changed ?

A. Geometry

B. Geometrical isomerism

C. Optical isomerism

D. Magnetic properties

A and D

A, B and D

A, B and C

B and C

Question 106: Palette 106/274

JEE Mains 2023 MCQ

Match List I with List II

	LIST I Complex		LIST II Colour
A.	$Mg(N{H_4})P{O_4}$	I.	brown
B.	${K_3}[Co{(N{O_2})_6}]$	II.	white
C.	$MnO{(OH)_2}$	III.	yellow
D.	$F{e_4}{[Fe{(CN)_6}]_3}$	IV.	blue

Choose the correct answer from the options given below :

A-II, B-IV, C-I, D-III

A-II, B-III, C-I, D-IV

A-III, B-IV, C-II, D-I

A-II, B-III, C-IV, D-I

Question 107: Palette 107/274

JEE Mains 2023 MCQ

The magnetic moment is measured in Bohr Magneton (BM).

Spin only magnetic moment of $\mathrm{Fe}$ in $\left[\mathrm{Fe}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{3+}$ and $\left[\mathrm{Fe}(\mathrm{CN})_{6}\right]^{3-}$ complexes respectively is :

3.87 B.M. and 1.732 B.M.

5.92 B.M. and 1.732 B.M.

6.92 B.M. in both

4.89 B.M. and 6.92 B.M.

Question 108: Palette 108/274

JEE Mains 2023 MCQ

The complex that dissolves in water is :

$\mathrm{Fe}_{4}\left[\mathrm{Fe}(\mathrm{CN})_{6}\right]_{3}$

$\left(\mathrm{NH}_{4}\right)_{3}\left[\mathrm{As}\left(\mathrm{Mo}_{3} \mathrm{O}_{10}\right)_{4}\right]$

$\mathrm{K}_{3}\left[\mathrm{Co}\left(\mathrm{NO}_{2}\right)_{6}\right]$

$\left[\mathrm{Fe}_{3}(\mathrm{OH})_{2}(\mathrm{OAc})_{6}\right] \mathrm{Cl}$

Question 109: Palette 109/274

JEE Mains 2023 MCQ

The set which does not have ambidentate ligand(s) is :

$\mathrm{C}_{2} \mathrm{O}_{4}{ }^{2-}, \mathrm{NO}_{2}{ }^{-}, \mathrm{NCS}^{-}$

$\mathrm{C}_{2} \mathrm{O}_{4}{ }^{2-}$, ethylene diammine, $\mathrm{H}_{2} \mathrm{O}$

$\mathrm{NO}_{2}^{-}, \mathrm{C}_{2} \mathrm{O}_{4}{ }^{2-}$, EDTA $^{4-}$

$\mathrm{EDTA}^{4-}, \mathrm{NCS}^{-}, \mathrm{C}_{2} \mathrm{O}_{4}{ }^{2-}$

Question 110: Palette 110/274

JEE Mains 2023 MCQ

Which of the following complex has a possibility to exist as meridional isomer?

$\mathrm{[Pt(NH_3)_2Cl_2]}$

$\left[\mathrm{Co}(\mathrm{en})_{2} \mathrm{Cl}_{2}\right]$

$\left[\mathrm{Co}(\mathrm{en})_{3}\right]$

$\left[\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{3}\left(\mathrm{NO}_{2}\right)_{3}\right]$

Question 111: Palette 111/274

JEE Mains 2023 MCQ

The correct order of the number of unpaired electrons in the given complexes is

A. $\left[\mathrm{Fe}(\mathrm{CN})_{6}\right]^{3-}$

B. $\left[\mathrm{Fe} \mathrm{F}_{6}\right]^{3-}$

C. $\left[\mathrm{CoF}_{6}\right]^{3-}$

D. $\left.[\mathrm{Cr} \text { (oxalate})_{3}\right]^{3-}$

E. $\left[\mathrm{Ni}(\mathrm{CO})_{4}\right]$

Choose the correct answer from the options given below:

E < A < B < D < C

A < E < D < C < B

A < E < C < B < D

E < A < D < C < B

Question 112: Palette 112/274

JEE Mains 2023 MCQ

Match List I with List II

	List - I Complex		List - II Crystal Field splitting energy ($\Delta_0$)
A.	${[Ti{({H_2}O)_6}]^{2 + }}$	I.	$-1.2$
B.	${[V{({H_2}O)_6}]^{2 + }}$	II.	$-0.6$
C.	${[Mn{({H_2}O)_6}]^{3 + }}$	III.	0
D.	${[Fe{({H_2}O)_6}]^{3 + }}$	IV.	$-0.8$

Choose the correct answer from the options given below:

A-IV, B-I, C-II, D-III

A-II, B-IV, C-III, D-I

A-II, B-IV, C-I, D-III

A-IV, B-I, C-III, D-II

Question 113: Palette 113/274

JEE Mains 2023 MCQ

The octahedral diamagnetic low spin complex among the following is :

[Co(NH$_3$)$_6$]$^{3+}$

[NiCl$_4$]$^{2-}$

[CoCl$_6$]$^{3-}$

[CoF$_6$]$^{3-}$

Question 114: Palette 114/274

JEE Mains 2023 MCQ

Match List I with List II

	LIST I Coordination Complex		LIST II Number of unpaired electrons
A.	$\left[\mathrm{Cr}(\mathrm{CN})_{6}\right]^{3-}$	I.	0
B.	$\left[\mathrm{Fe}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{2+}$	II.	3
C.	$\left[\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{6}\right]^{3+}$	III.	2
D.	$\left[\mathrm{Ni}\left(\mathrm{NH}_{3}\right)_{6}\right]^{2+}$	IV.	4

Choose the correct answer from the options given below:

A-IV, B-III, C-II, D-I

A-II, B-I, C-IV, D-III

A-II, B-IV, C-I, D-III

A-III, B-IV, C-I, D-II

Question 115: Palette 115/274

JEE Mains 2023 MCQ

Which of the following complex is octahedral, diamagnetic and the most stable?

$\mathrm{Na}_{3}\left[\mathrm{CoCl}_{6}\right]$

$\left[\mathrm{Co}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right] \mathrm{Cl}_{2}$

$\mathrm{K}_{3}\left[\mathrm{Co}(\mathrm{CN})_{6}\right]$

$\left[\mathrm{Ni}\left(\mathrm{NH}_{3}\right)_{6}\right] \mathrm{Cl}_{2}$

Question 116: Palette 116/274

JEE Mains 2023 MCQ

The correct order of spin only magnetic moments for the following complex ions is

$\left[\mathrm{Fe}(\mathrm{CN})_{6}\right]^{3-}<\left[\mathrm{CoF}_{6}\right]^{3-}<\left[\mathrm{MnBr}_{4}\right]^{2-}<\left[\mathrm{Mn}(\mathrm{CN})_{6}\right]^{3-}$

$\left[\mathrm{MnBr}_{4}\right]^{2-}<\left[\mathrm{CoF}_{6}\right]^{3-}<\left[\mathrm{Fe}(\mathrm{CN})_{6}\right]^{3-}<\left[\mathrm{Mn}(\mathrm{CN})_{6}\right]^{3-}$

$\left[\mathrm{Fe}(\mathrm{CN})_{6}\right]^{3-}<\left[\mathrm{Mn}(\mathrm{CN})_{6}\right]^{3-}<\left[\mathrm{CoF}_{6}\right]^{3-}<\left[\mathrm{MnBr}_{4}\right]^{2-}$

$\left[\mathrm{CoF}_{6}\right]^{3-}<\left[\mathrm{MnBr}_{4}\right]^{2-}<\left[\mathrm{Fe}(\mathrm{CN})_{6}\right]^{3-}<\left[\mathrm{Mn}(\mathrm{CN})_{6}\right]^{3-}$

Question 117: Palette 117/274

JEE Mains 2023 MCQ

The IUPAC name of $\mathrm{K}_{3}\left[\mathrm{Co}\left(\mathrm{C}_{2} \mathrm{O}_{4}\right)_{3}\right]$ is:-

Potassium tris(oxalato)cobalt(III)

Potassium tris(oxalato)cobaltate(III)

Potassium trioxalatocobaltate(III)

Potassium trioxalatocobalt(III)

Question 118: Palette 118/274

JEE Mains 2023 MCQ

Given below are two statements, one is labelled as Assertion $\mathbf{A}$ and the other is labelled as Reason $\mathbf{R}$.

Assertion A: The spin only magnetic moment value for $\left[\mathrm{Fe}(\mathrm{CN})_{6}\right]^{3-}$ is $1.74 \mathrm{BM}$, whereas for $\left[\mathrm{Fe}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{3+}$ is $5.92 \mathrm{BM}$.

Reason $\mathbf{R}$ : In both complexes, $\mathrm{Fe}$ is present in +3 oxidation state.

In the light of the above statements, choose the correct answer from the options given below:

Both A and R are true and R is the correct explanation of A

A is true but R is false

A is false but R is true

Both A and R are true but R is NOT the correct explanation of A

Question 119: Palette 119/274

JEE Mains 2023 MCQ

The complex cation which has two isomers is :

$\left[\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{5} \mathrm{Cl}\right]^{+}$

$\left[\mathrm{Co}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{3+}$

$\left[\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{5} \mathrm{NO}_{2}\right]^{2+}$

$\left[\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{5} \mathrm{Cl}\right]^{2+}$

Question 120: Palette 120/274

JEE Mains 2023 MCQ

Which of the following complex will show largest splitting of d-orbitals?

$[\mathrm{Fe(C_2O_4)_3]^{3-}}$

$[\mathrm{Fe(CN)_6]^{3-}}$

$[\mathrm{Fe(NH_3)_6]^{3+}}$

$[\mathrm{FeF_6]^{3-}}$

Question 121: Palette 121/274

JEE Mains 2023 MCQ

Which of the following are the example of double salt?

A. $\mathrm{FeSO}_{4} \cdot\left(\mathrm{NH}_{4}\right)_{2} \mathrm{SO}_{4} \cdot 6 \mathrm{H}_{2} \mathrm{O}$

B. $\mathrm{CuSO}_{4}\cdot 4 \mathrm{NH}_{3} \cdot \mathrm{H}_{2} \mathrm{O}$

C. $\mathrm{K}_{2} \mathrm{SO}_{4} \cdot \mathrm{Al}_{2}\left(\mathrm{SO}_{4}\right)_{3} \cdot 24 \mathrm{H}_{2} \mathrm{O}$

D. $\mathrm{Fe}(\mathrm{CN})_{2}\cdot4 \mathrm{KCN}$

Choose the correct answer :

A, B and D only

B and D only

A and B only

A and C only

Question 122: Palette 122/274

JEE Mains 2023 MCQ

A solution of $\mathrm{FeCl_3}$ when treated with $\mathrm{K_4[Fe(CN)_6]}$ gives a prussium blue precipitate due to the formation of :

$\mathrm{Fe[Fe(CN)_{6}]}$

$\mathrm{Fe_{4}[Fe(CN)_{6}]_{3}}$

$\mathrm{Fe_{3}[Fe(CN)_{6}]_{2}}$

$\mathrm{K[Fe_{2}(CN)_{6}]}$

Question 123: Palette 123/274

JEE Mains 2023 MCQ

Cobalt chloride when dissolved in water forms pink colored complex $\underline{\mathrm{X}}$ which has octahedral geometry. This solution on treating with conc $\mathrm{HCl}$ forms deep blue complex, $\underline{\mathrm{Y}}$ which has a $\underline{\mathrm{Z}}$ geometry. $\mathrm{X}, \mathrm{Y}$ and $\mathrm{Z}$, respectively, are

$\mathrm{X}=\left[\mathrm{Co}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{2+}, \mathrm{Y}=\left[\mathrm{CoCl}_{4}\right]^{2-}, \mathrm{Z}=$ Tetrahedral

$\mathrm{X}=\left[\mathrm{Co}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{2+}, \mathrm{Y}=\left[\mathrm{CoCl}_{6}\right]^{3-}, \mathrm{Z}=$ Octahedral

$\mathrm{X}=\left[\mathrm{Co}\left(\mathrm{H}_{2} \mathrm{O}\right)_{4} \mathrm{Cl}_{2}\right]^{+}, \mathrm{Y}=\left[\mathrm{CoCl}_{4}\right]^{2-}, \mathrm{Z}=$ Tetrahedral

$\mathrm{X}=\left[\mathrm{Co}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{3+}, \mathrm{Y}=\left[\mathrm{CoCl}_{6}\right]^{3-}, \mathrm{Z}=$ Octahedral

Question 124: Palette 124/274

JEE Mains 2023 MCQ

Match List I with List II:

List I (Complexes)		List II (Hybridisation)
A.	$\left[\mathrm{Ni}(\mathrm{CO})_{4}\right]$	I.	$\mathrm{sp}^{3}$
B.	$\left[\mathrm{Cu}\left(\mathrm{NH}_{3}\right)_{4}\right]^{2+}$	II.	dsp$^{2}$
C.	$\left[\mathrm{Fe}\left(\mathrm{NH}_{3}\right)_{6}\right]^{2+}$	III.	$\mathrm{sp}^{3}\mathrm{d}^{2}$
D.	$\left[\mathrm{Fe}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{2+}$	IV.	$\mathrm{d}^{2} \mathrm{sp}^{3}$

A-I, B-II, C-III, D-IV

A-II, B-I, C-III, D-IV

A-I, B-II, C-IV, D-III

A-II, B-I, C-IV, D-III

Question 125: Palette 125/274

JEE Mains 2023 MCQ

The $\mathrm{Cl}-\mathrm{Co}-\mathrm{Cl}$ bond angle values in a fac- $\left[\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{3} \mathrm{Cl}_{3}\right]$ complex is/are :

$90^{\circ} ~\&~ 120^{\circ}$

$90^{\circ}$

$180^{\circ}$

$90^{\circ} ~\& ~180^{\circ}$

Question 126: Palette 126/274

JEE Mains 2023 MCQ

To inhibit the growth of tumours, identify the compounds used from the following :

A. EDTA

B. Coordination Compounds of Pt

C. D - Penicillamine

D. Cis - Platin

Choose the correct answer from the option given below :

A and B Only

C and D Only

B and D Only

A and C Only

Question 127: Palette 127/274

JEE Mains 2023 MCQ

Which of the following is correct order of ligand field strength?

$\mathrm{S}^{2-}<\mathrm{C}_{2} \mathrm{O}_{4}^{2-}<\mathrm{NH}_{3} < $ en $<\mathrm{CO}$

$\mathrm{CO}<\mathrm{en}<\mathrm{NH}_{3}<\mathrm{C}_{2} \mathrm{O}_{4}^{2}<\mathrm{S}^{2-}$

$\mathrm{S}^{2-}<\mathrm{NH}_{3}<$ en $<\mathrm{CO}<\mathrm{C}_{2} \mathrm{O}_{4}^{2}$

$\mathrm{NH}_{3}<\mathrm{en}<\mathrm{CO}<\mathrm{S}^{2-}<\mathrm{C}_{2} \mathrm{O}_{4}^{2}$

Question 128: Palette 128/274

JEE Mains 2023 MCQ

Correct order of spin only magnetic moment of the following complex ions is :

(Given At.no. Fe : 26, Co : 27)

$\mathrm{[CoF_6]^{3-} > [FeF_6]^{3-} > [Co(C_2O_4)_3]^{3-}}$

$\mathrm{[FeF_6]^{3-} > [Co(C_2O_4)_3]^{3-} > [CoF_6]^{3-}}$

$\mathrm{[FeF_6]^{3-} > [CoF_6]^{3-} > [Co(C_2O_4)_3]^{3-}}$

$\mathrm{[Co(C_2O_4)_3]^{3-} > [CoF_6]^{3-} > [FeF_6]^{3-}}$

Question 129: Palette 129/274

JEE Mains 2023 MCQ

Chiral complex from the following is :

Here en = ethylene diamine

$\mathrm{cis-[PtCl_2(en)_2]^{2+}}$

$\mathrm{trans-[Co(NH_3)_4Cl_2]^{+}}$

$\mathrm{trans-[PtCl_2(en)_2]^{2+}}$

$\mathrm{cis-[PtCl_2(NH_3)_2]}$

Question 130: Palette 130/274

JEE Mains 2023 MCQ

Match List I with List II

	List I Coordination entity		List II Wavelength of light absorbed in nm
A.	$\mathrm{[CoCl(NH_3)_5]^{2+}}$	I.	310
B.	$\mathrm{[Co(NH_3)_6]^{3+}}$	II.	475
C.	$\mathrm{[Co(CN)_6]^{3-}}$	III.	535
D.	$\mathrm{[Cu(H_2O)_4]^{2+}}$	IV.	600

Choose the correct answer from the options given below :

A-IV, B-I, C-III, D-II

A-III, B-II, C-I, D-IV

A-III, B-I, C-II, D-IV

A-II, B-III, C-IV, D-I

Question 131: Palette 131/274

JEE Mains 2023 MCQ

The hybridization and magnetic behaviour of cobalt ion in $\mathrm{[Co(NH_3)_6]^{3+}}$ complex, respectively is :

$\mathrm{sp^3d^2}$ and paramagnetic

$\mathrm{sp^3d^2}$ and diamagnetic

$\mathrm{d^2sp^3}$ and diamagnetic

$\mathrm{d^2sp^3}$ and paramagnetic

Question 132: Palette 132/274

JEE Mains 2023 MCQ

Which of the following cannot be explained by crystal field theory?

The order of spectrochemical series

Stability of metal complexes

Magnetic properties of transition metal complexes

Colour of metal complexes

Question 133: Palette 133/274

JEE Mains 2023 MCQ

The primary and secondary valencies of cobalt respectively in $\mathrm{[Co(NH_3)_5Cl]Cl_2}$ are :

2 and 8

2 and 6

3 and 5

3 and 6

Question 134: Palette 134/274

JEE Mains 2022 MCQ

Octahedral complexes of copper(II) undergo structural distortion (Jahn-Teller). Which one of the given copper (II) complexes will show the maximum structural distortion? (en - ethylenediamine; $\mathrm{H}_{2} \mathrm{~N}_{-} \mathrm{CH}_{2}-\mathrm{CH}_{2}-\mathrm{NH}_{2}$)

$\left[\mathrm{Cu}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right] \mathrm{SO}_{4}$

$\left[\mathrm{Cu}(\mathrm{en})\left(\mathrm{H}_{2} \mathrm{O}\right)_{4}\right] \mathrm{SO}_{4}$

cis-$\left[\mathrm{Cu}\left(\mathrm{en})_{2} \mathrm{Cl}_{2}\right]\right.$

trans-$\left[\mathrm{Cu}\left(\mathrm{en})_{2} \mathrm{Cl}_{2}\right]\right.$

Question 135: Palette 135/274

JEE Mains 2022 MCQ

Match List I with List II

	List - I (Complex)		List - II (Hybridization)
(A)	$Ni{(CO)_4}$	(I)	$s{p^3}$
(B)	${[Ni{(CN)_4}]^{2 - }}$	(II)	$s{p^3}{d^2}$
(C)	${[Co{(CN)_6}]^{3 - }}$	(III)	${d^2}s{p^3}$
(D)	${[Co{F_6}]^{3 - }}$	(IV)	$ds{p^2}$

Choose the correct answer from the options given below :

A-IV, B-I, C-III, D-II

A-I, B-IV, C-III, D-II

A-I, B-IV, C-II, D-III

A-IV, B-I, C-II, D-III

Question 136: Palette 136/274

JEE Mains 2022 MCQ

Low oxidation state of metals in their complexes are common when ligands :

have good $\pi$-accepting character

have good $\sigma$-donor character

are having good $\pi$-donating ability

are having poor $\sigma$-donating ability

Question 137: Palette 137/274

JEE Mains 2022 MCQ

$\mathrm{Fe}^{3+}$ cation gives a prussian blue precipitate on addition of potassium ferrocyanide solution due to the formation of :

$\left[\mathrm{Fe}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]_{2}\left[\mathrm{Fe}(\mathrm{CN})_{6}\right]$

$\mathrm{Fe}_{2}\left[\mathrm{Fe}(\mathrm{CN})_{6}\right]_{2}$

$\mathrm{Fe}_{3}\left[\mathrm{Fe}(\mathrm{OH})_{2}(\mathrm{CN})_{4}\right]_{2}$

$\mathrm{Fe}_{4}\left[\mathrm{Fe}(\mathrm{CN})_{6}\right]_{3}$

Question 138: Palette 138/274

JEE Mains 2022 MCQ

The metal complex that is diamagnetic is (Atomic number: $\mathrm{Fe}, 26 ; \mathrm{Cu}, 29)$

$\mathrm{K}_{3}\left[\mathrm{Cu}(\mathrm{CN})_{4}\right]$

$\mathrm{K}_{2}\left[\mathrm{Cu}(\mathrm{CN})_{4}\right]$

$\mathrm{K}_{3}\left[\mathrm{Fe}(\mathrm{CN})_{4}\right]$

$\mathrm{K}_{4}\left[\mathrm{FeCl}_{6}\right]$

Question 139: Palette 139/274

JEE Mains 2022 MCQ

The correct order of energy of absorption for the following metal complexes is :

A : [Ni(en)₃]²⁺ , B : [Ni(NH₃)₆]²⁺ , C : [Ni(H₂O)₆]²⁺

C < B < A

B < C < A

C < A < B

A < C < B

Question 140: Palette 140/274

JEE Mains 2022 MCQ

Correct formula of the compound which gives a white precipitate with BaCl₂ solution, but not with AgNO₃ solution, is :

[Co(NH₃)₅Br]SO₄

[Co(NH₃)₅SO₄]Br

[Pt(NH₃)₄Cl₂]Br₂

[Pt(NH₃)₄Br₂]Cl₂

Question 141: Palette 141/274

JEE Mains 2022 MCQ

Given below are two statements.

$\bullet$ Statement I : In CuSO₄ . 5H₂O, Cu-O bonds are present.

$\bullet$ Statement II : In CuSO₄ . 5H₂O, ligands coordinating with Cu(II) ion are O-and S-based ligands.

In the light of the above statements, choose the correct answer from the options given below.

Both Statement I and Statement II are correct.

Both Statement I and Statement II are incorrect.

Statement I is correct but Statement II is incorrect.

Statement I is incorrect but Statement II is correct.

Question 142: Palette 142/274

JEE Mains 2022 MCQ

Given below are two statements :

Statement I : [Ni(CN)₄]^2$-$ is square planar and diamagnetic complex, with dsp² hybridization for Ni but [Ni(CO)₄] is tetrahedral, paramagnetic and with sp³-hybridication for Ni.

Statement II : [NiCl₄]^2$-$ and [Ni(CO)₄] both have same d-electron configuration have same geometry and are paramagnetic.

In light the above statements, choose the correct answer from the options given below :

Both Statement I and Statement II are true.

Both Statement I and Statement II are false.

Statement I is correct but Statement II is false.

Statement I is false but Statement II is correct.

Question 143: Palette 143/274

JEE Mains 2022 MCQ

Arrange the following coordination compounds in the increasing order of magnetic moments. (Atomic numbers : Mn = 25; Fe = 26)

A. [FeF₆]^3$-$

B. [Fe(CN)₆]^3$-$

C. [MnCl₆]^3$-$ (high spin)

D. [Mn(CN)₆]^3$-$

Choose the correct answer from the options given below :

A < B < D < C

B < D < C < A

A < C < D < B

B < D < A < C

Question 144: Palette 144/274

JEE Mains 2022 MCQ

Which of the following will have maximum stabilization due to crystal field?

[Ti(H₂O)₆]³⁺

[Co(H₂O)₆]²⁺

[Co(CN)₆]^3$-$

[Cu(NH₃)₄]²⁺

Question 145: Palette 145/274

JEE Mains 2022 MCQ

Which statement is not true with respect to nitrate ion test?

A dark brown ring is formed at the junction of two solutions.

Ring is formed due to nitroferrous sulphate complex.

The brown complex is [Fe(H₂O)₅ (NO)]SO₄.

Heating the nitrate salt with conc. H₂SO₄, light brown fumes are evolved.

Question 146: Palette 146/274

JEE Mains 2022 MCQ

Transition metal complex with highest value of crystal field splitting ($\Delta$₀) will be :

[Cr(H₂O)₆]³⁺

[Mo(H₂O)₆]³⁺

[Fe(H₂O)₆]³⁺

[Os(H₂O)₆]³⁺

Question 147: Palette 147/274

JEE Mains 2022 MCQ

Match List - I with List - II :

	List - I		List -II
(A)	${[PtC{l_4}]^{2 - }}$	(I)	$s{p^3}d$
(B)	$Br{F_5}$	(II)	${d^2}s{p^3}$
(C)	$PC{l_5}$	(III)	$ds{p^2}$
(D)	${[Co{(N{H_3})_6}]^{3 + }}$	(IV)	$s{p^3}{d^2}$

Choose the most appropriate answer from the options given below :

(A)-(II), (B)-(IV), (C)-(I), (D)-(III)

(A)-(III), (B)-(IV), (C)-(I), (D)-(II)

(A)-(III), (B)-(I), (C)-(IV), (D)-(II)

(A)-(II), (B)-(I), (C)-(IV), (D)-(III)

Question 148: Palette 148/274

JEE Mains 2021 MCQ

The Crystal Field Stabilization Energy (CFSE) and magnetic moment (spin-only) of an octahedral aqua complex of a metal ion (M^z+) are $-$0.8 $\Delta$₀ and 3.87 BM, respectively. Identify (M^z+) :

V³⁺

Cr³⁺

Mn⁴⁺

Co²⁺

Question 149: Palette 149/274

JEE Mains 2021 MCQ

The potassium ferrocyanide solution gives a Prussian blue colour, when added to :

CoCl₃

FeCl₂

CoCl₂

FeCl₃

Question 150: Palette 150/274

JEE Mains 2021 MCQ

Spin only magnetic moment in BM of [Fe(CO)₄(C₂O₄)]⁺ is :

5.92

1.73

Question 151: Palette 151/274

JEE Mains 2021 MCQ

The denticity of an organic ligand, biuret is :

Question 152: Palette 152/274

JEE Mains 2021 MCQ

Indicate the complex/complex ion which did not show any geometrical isomerism :

[CoCl₂(en)₂]

[Co(CN)₅(NC)]^3$-$

[Co(NH₃)₃(NO₂)₃]

[Co(NH₃)₄Cl₂]⁺

Question 154: Palette 154/274

JEE Mains 2021 MCQ

Given below are two statements :

Statement I : ${[Mn{(CN)_6}]^{3 - }}$, ${[Fe{(CN)_6}]^{3 - }}$ and ${[Co{({C_2}{O_4})_3}]^{3 - }}$ are d²sp³ hybridised.

Statement II : ${[MnCl)_6}{]^{3 - }}$ and ${[Fe{F_6}]^{3 - }}$ are paramagnetic and have 4 and 5 unpaired electrons, respectively.

In the light of the above statements, choose the correct answer from the options given below :

Statement I is correct but statement II is false

Both statement I and Statement II are false

Statement I is incorrect but statement II is true

Both statement I and statement II are true

Question 155: Palette 155/274

JEE Mains 2021 MCQ

The type of hybridisation and magnetic property of the complex [MnCl₆]^3$-$, respectively, are :

sp³d² and diamagnetic

d²sp³ and diamagnetic

d²sp³ and paramagnetic

sp³d² and paramagnetic

Question 156: Palette 156/274

JEE Mains 2021 MCQ

The number of geometrical isomers found in the metal
complexes [PtCl₂(NH₃)₂], [Ni(CO)₄], [Ru(H₂O)₃Cl₃ and [CoCl₂(NH₃)₄]⁺ respectively, are :

1, 1, 1, 1

2, 1, 2, 2

2, 0, 2, 2

2, 1, 2, 1

Question 157: Palette 157/274

JEE Mains 2021 MCQ

Which one of the following metal complexes is most stable?

[Co(en)(NH₃)₄]Cl₂

[Co(en)₃]Cl₂

[Co(en)₂(NH₃)₂]Cl₂

[Co(NH₃)₆]Cl₂

Question 158: Palette 158/274

JEE Mains 2021 MCQ

Which one of the following species responds to an external magnetic field?

[Fe(H₂O)₆]³⁺

[Ni(CN)₄]^2$-$

[Co(CN)₆]^3$-$

[Ni(CO)₄]

Question 159: Palette 159/274

JEE Mains 2021 MCQ

Spin only magnetic moment of an octahedral complex of Fe²⁺ in the presence of a strong field ligand in BM is :

4.89

2.82

3.46

Question 160: Palette 160/274

JEE Mains 2021 MCQ

Which one of the following species doesn't have a magnetic moment of 1.73 BM, (spin only value)?

O$_2^ + $

CuI

[Cu(NH₃)₄]Cl₂

O$_2^ - $

Question 161: Palette 161/274

JEE Mains 2021 MCQ

According to the valence bond theory the hybridization of central metal atom is dsp² for which one of the following compounds?

$NiC{l_2}.6{H_2}O$

${K_2}[Ni{(CN)_4}]$

$[Ni{(CO)_4}]$

$N{a_2}[NiC{l_4}]$

Question 162: Palette 162/274

JEE Mains 2021 MCQ

The correct order of intensity of colors of the compounds is :

${[Ni{(CN)_4}]^{2 - }} > {[NiC{l_4}]^{2 - }} > {[Ni{({H_2}O)_6}]^{2 + }}$

${[Ni{({H_2}O)_6}]^{2 + }} > {[NiC{l_4}]^{2 - }} > {[Ni{(CN)_4}]^{2 - }}$

${[NiC{l_4}]^{2 - }} > {[Ni{({H_2}O)_6}]^{2 + }} > {[Ni{(CN)_4}]^{2 - }}$

${[NiC{l_4}]^{2 - }} > {[Ni{(CN)_4}]^{2 - }} > {[Ni{({H_2}O)_6}]^{2 + }}$

Question 163: Palette 163/274

JEE Mains 2021 MCQ

The secondary valency and the number of hydrogen bonded water molecule(s) in CuSO₄ . 5H₂O, respectively, are :

5 and 1

4 and 1

6 and 5

6 and 4

Question 164: Palette 164/274

JEE Mains 2021 MCQ

The correct structures of trans-[NiBr₂(PPh₃)₂] and meridonial-[Co(NH₃)₃(NO₂)₃], respectively, are

JEE Main 2021 (Online) 18th March Morning Shift Chemistry - Coordination Compounds Question 233 English Option 1

JEE Main 2021 (Online) 18th March Morning Shift Chemistry - Coordination Compounds Question 233 English Option 2

JEE Main 2021 (Online) 18th March Morning Shift Chemistry - Coordination Compounds Question 233 English Option 3

JEE Main 2021 (Online) 18th March Morning Shift Chemistry - Coordination Compounds Question 233 English Option 4

Question 165: Palette 165/274

JEE Mains 2021 MCQ

Match List - I with List - II :

	List - I		List - II
(a)	$[Co{(N{H_3})_6}][Cr{(CN)_6}]$	(i)	Linkage isomerism
(b)	$[Co{(N{H_3})_3}{(N{O_2})_3}]$	(ii)	Solvate isomerism
(c)	$[Cr{({H_2}O)_6}C{l_3}$	(iii)	Co-ordination isomerism
(d)	$cis - {[CrC{l_2}{(ox)_2}]^{3 - }}$	(iv)	Optical isomerism

Choose the correct answer from the options given below :

(a)-(i), (b)-(ii), (c)-(iii), (d)-(iv)

(a)-(iii), (b)-(i), (c)-(ii), (d)-(iv)

(a)-(ii), (b)-(i), (c)-(iii), (d)-(iv)

(a)-(iv), (b)-(ii), (c)-(iii), (d)-(i)

Question 166: Palette 166/274

JEE Mains 2021 MCQ

In which of the following order the given complex ions are arranged correctly with respect to their decreasing spin only magnetic moment?

(i) [FeF₆]^3$-$

(ii) [Co(NH₃)₆]³⁺

(iii) [NiCl₄]^2$-$

(iv) [Cu(NH₃)₄]²⁺

(iii) > (iv) > (ii) > (i)

(ii) > (iii) > (i) > (iv)

(i) > (iii) > (iv) > (ii)

(ii) > (i) > (iii) > (iv)

Question 167: Palette 167/274

JEE Mains 2021 MCQ

The hybridization and magnetic nature of ${[Mn{(CN)_6}]^{4 - }}$ and ${[Fe{(CN)_6}]^{3 - }}$, respectively are :

sp³d² and diamagnetic

d²sp³ and paramagnetic

sp³d² and paramagnetic

d²sp³ and diamagnetic

Question 168: Palette 168/274

JEE Mains 2021 MCQ

The calculated magnetic moments (spin only value) for species ${[FeC{l_4}]^{2 - }}$, ${[Co{({C_2}{O_4})_3}]^{3 - }}$ and $MnO_4^{2 - }$ respectively are :

5.92, 4.90 and 0 BM

4.90, 0 and 1.73 BM

5.82, 0 and 0 BM

4.90, 0 and 2.83 BM

Question 169: Palette 169/274

JEE Mains 2020 MCQ

For a d⁴ metal ion in an octahedral field, the correct electronic configuration is :

$t_{2g}^4e_g^0$ when $\Delta $₀ < P

$t_{2g}^3e_g^1$ when $\Delta $₀ > P

$e_g^2t_{2g}^2$ when $\Delta $₀ < P

$t_{2g}^3e_g^1$ when $\Delta $₀ < P

Question 170: Palette 170/274

JEE Mains 2020 MCQ

The species that has a spin-only magnetic moment of 5.9 BM, is :
(T_d = tetrahedral)

[MnBr₄]^2– (T_d)

[NiCl₄]^2– (T_d)

Ni(CO)₄ (T_d)

[Ni(CN)₄]^2– (square planar)

Question 171: Palette 171/274

JEE Mains 2020 MCQ

Consider the complex ions,
trans-[Co(en)₂Cl₂]⁺ (A) and
cis-[Co(en)₂Cl₂]⁺ (B).
The correct statement regarding them is :

both (A) and (B) can be optically active.

both (A) and (B) can not be optically active.

(A) can not be optically active, but (B) can be optically active.

(A) can be optically active, but (B) can not be optically active.

Question 172: Palette 172/274

JEE Mains 2020 MCQ

The values of the crystal field stabilization energies for a high spin d⁶ metal ion in octahedral and tetrahedral fields, respectively, are :

–0.4$\Delta $₀ and –0.27$\Delta $_t

–1.6$\Delta $₀ and –0.4$\Delta $_t

–0.4$\Delta $₀ and –0.6$\Delta $_t

–2.4$\Delta $₀ and –0.27$\Delta $_t

Question 173: Palette 173/274

JEE Mains 2020 MCQ

The one that can exhibit highest paramagnetic behaviour among the following is :

gly = glycinato; bpy = 2, 2'-bipyridine

[Fe(en)(bpy)(NH₃)₂]²⁺

[Pd(gly)₂]

[Co(OX)₂(OH)₂]^– ($\Delta $₀ > P)

[Ti(NH₃)₆]³⁺

Question 174: Palette 174/274

JEE Mains 2020 MCQ

The Crystal Field Stabilization Energy
(CFSE) of [CoF₃(H₂O)₃] ($\Delta $₀ < P) is :

-0.8 $\Delta $₀

-0.4 $\Delta $₀

-0.8 $\Delta $₀ + 2P

-0.4 $\Delta $₀ + P

Question 175: Palette 175/274

JEE Mains 2020 MCQ

The molecule in which hybrid MOs involve only one d-orbital of the central atom is :

XeF₄

[Ni(CN)₄]^2–

[CrF₆]^3–

BrF₅

Question 176: Palette 176/274

JEE Mains 2020 MCQ

The pair in which both the species have the same magnetic moment (spin only) is :

[Cr(H₂O)₆]²⁺ and [CoCl₄]^2–

[Co(OH)₄]^2– and [Fe(NH₃)₆]²⁺

[Mn(H₂O)₆]²⁺ and [Cr(H₂O)]²⁺

[Cr(H₂O)₆]²⁺ and [Fe(H₂O)₆]²⁺

Question 177: Palette 177/274

JEE Mains 2020 MCQ

The number of isomers possible for
[Pt(en)(NO₂)₂] is :

Question 178: Palette 178/274

JEE Mains 2020 MCQ

The d-electron configuration of [Ru(en)₃ ]Cl₂
and [Fe(H₂O)₆]Cl₂ , respectively are :

$t_{2g}^4e_g^2$ and $t_{2g}^6e_g^0$

$t_{2g}^6e_g^0$ and $t_{2g}^6e_g^0$

$t_{2g}^6e_g^0$ and $t_{2g}^4e_g^2$

$t_{2g}^4e_g^2$ and $t_{2g}^4e_g^2$

Question 179: Palette 179/274

JEE Mains 2020 MCQ

Complex A has a composition of H₁₂O₆Cl₃Cr. If the complex on treatment with conc.H₂SO₄ loses 13.5% of its original mass, the correct molecular formula of A is :
[Given: atomic mass of Cr = 52 amu and Cl = 35 amu]

[Cr(H₂O)₅Cl]Cl₂.H₂O

[Cr(H₂O)₄Cl₂]Cl.2H₂O

[Cr(H₂O)₃Cl₃].3H₂O

[Cr(H₂O)₆]Cl₃

Question 180: Palette 180/274

JEE Mains 2020 MCQ

The complex that can show optical activity is :

cis-[Fe(NH₃)₂(CN)₄]^–

trans-[Cr(Cl₂)(ox)₂]^3–

trans-[Fe(NH₃)₂(CN)₄]^–

cis-[CrCl₂(ox)₂]^3– (ox = oxalate)

Question 181: Palette 181/274

JEE Mains 2020 MCQ

The electronic spectrum of [Ti(H₂O)₆]³⁺ shows a single broad peak with a maximum at 20,300 cm^-1 . The crystal field stabilization energy (CFSE) of the complex ion, in kJ mol^-1, is :

83.7

242.5

145.5

Question 182: Palette 182/274

JEE Mains 2020 MCQ

The one that is not expected to show isomerism is :

[Pt(NH₃)₂Cl₂]

[Ni(NH₃)₄(H₂O)₂]²⁺

[Ni(en)₃]²⁺

[Ni(NH₃)₂Cl₂]

Question 183: Palette 183/274

JEE Mains 2020 MCQ

Simplified absorption spectra of three complexes ((i), (ii) and (iii)) of Mn⁺ ion are provided below; their $\lambda $_max values are marked as A, B and C respectively. The correct match between the complexes and their $\lambda $_max values is JEE Main 2020 (Online) 2nd September Evening Slot Chemistry - Coordination Compounds Question 261 English

JEE Main 2020 (Online) 2nd September Evening Slot Chemistry - Coordination Compounds Question 261 English

(i) [M(NCS)₆]^{(–6 + n)}
(ii) [MF₆]^{(–6 + n)}
(iii) [M(NH₃)₆]ⁿ⁺

A-(i), B-(ii), C-(iii)

A-(ii), B-(iii), C-(i)

A-(ii), B-(i), C-(iii)

A-(iii), B-(i), C-(ii)

Question 184: Palette 184/274

JEE Mains 2020 MCQ

For octahedral Mn(II) and tetrahedral Ni(II) complexes, consider the following statements:

(I) both the complexes can be high spin.
(II) Ni(II) complex can very rarely be low spin.
(III) with strong field ligands, Mn(II) complexes can be low spin.
(IV)aqueous solution of Mn(II) ions is yellow in colour.

The correct statements are :

(I), (III) and (IV) only

(I) and (II) only

(II), (III) and (IV) only

(I), (II) and (III) only

Question 185: Palette 185/274

JEE Mains 2020 MCQ

Consider that a d⁶ metal ion (M²⁺) forms a complex with aqua ligands, and the spin only magnetic moment of the complex is 4.90 BM. The geometry and the crystal field stabilization energy of the complex is

tetrahedral and – 1.6 $\Delta $_t + 1P

octahedral and –2.4 $\Delta $₀ + 2P

tetrahedral and –0.6 $\Delta $_t

octahedral and –1.6 $\Delta $₀

Question 186: Palette 186/274

JEE Mains 2020 MCQ

The correct order of the spin-only magnetic moments of the following complexes is :
(I) [Cr(H₂O)₆]Br₂
(II) Na₄[Fe(CN)₆]
(III) Na₃[Fe(C₂O₄)₃] ($\Delta $₀ $>$ P)
(IV) (Et₄N)₂[CoCl₄]

(III) > (I) > (II) > (IV)

(II) $ \approx $ (I) > (IV) > (III)

(III) > (I) > (IV) > (II)

(I) > (IV) > (III) > (II)

Question 187: Palette 187/274

JEE Mains 2020 MCQ

The isomer(s) of [Co(NH₃)₄Cl₂] that has/have a Cl–Co–Cl angle of 90°, is/are :

cis only

cis and trans

meridional and trans

trans only

Question 188: Palette 188/274

JEE Mains 2020 MCQ

Complex X of composition Cr(H₂O)₆Cl_n has a spin only magnetic moment of 3.83 BM. It reacts with AgNO₃ and shows geometrical isomerism. The IUPAC nomenclature of X is :

Hexaaqua chromium (III) chloride

Tetraaquadichlorido chromium(IV) chloride dihydrate

Tetraaquadichlorido chromium (III) chloride dihydrate

Dichloridotetraaqua chromium (IV) chloride dihydrate

Question 189: Palette 189/274

JEE Mains 2020 MCQ

[Pd(F)(Cl)(Br)(I)]^2– has n number of geometrical isomers. Then, the spin-only magnetic moment and crystal field stabilisation energy [CFSE] of [Fe(CN)₆]^n–6, respectively, are:
[Note : Ignore the pairing energy]

1.73 BM and –2.0 $\Delta $₀

5.92 BM and 0

2.84 BM and –1.6 $\Delta $₀

0 BM and –2.4 $\Delta $₀

Question 190: Palette 190/274

JEE Mains 2020 MCQ

The correct order of the calculated spin-only magnetic moments of complexs (A) to (D) is:
(A) Ni(CO)₄
(B) [Ni(H₂O)₆]Cl₂
(C) Na₂[Ni(CN)₄]
(D) PdCl₂(PPh₃)₂

(A) $ \approx $ (C) $ \approx $ (D) < (B)

(A) $ \approx $ (C) < (B) $ \approx $ (D)

Question 191: Palette 191/274

JEE Mains 2020 MCQ

Among (a) – (d) the complexes that can display geometrical isomerism are :
(a) [Pt(NH₃)₃Cl]⁺
(b) [Pt(NH₃)Cl₅]^–
(c) [Pt(NH₃)₂Cl(NO₂)]
(d) [Pt(NH₃)₄ClBr]²⁺

(a) and (b)

(d) and (a)

(b) and (c)

Question 192: Palette 192/274

JEE Mains 2020 MCQ

The complex that can show fac- and mer-isomers is :

[CoCl₂(en)₂]

[Pt(NH₃)₂Cl₂]

[Co(NH₃)₃(NO₂)₃]

[Co(NH₃)₄Cl₂]⁺

Question 193: Palette 193/274

JEE Mains 2020 MCQ

The number of possible optical isomers for the complexes MA₂B₂ with sp³ and dsp² hydridized metal atom. respectively, is :
Note : A and B are unidentate netural and unidentate monoanionic ligands, respectively.

0 and 2

0 and 0

0 and 1

2 and 2

Question 194: Palette 194/274

JEE Mains 2020 MCQ

Among the statements(a)-(d) the incorrect ones are :
(a) Octahedral CO(III) complexes with strong fields ligands have very high magnetic moments.
(b) When $\Delta $₀ < P, the d-electron configuration of Co(III) in an octahedral complex is $t_{eg}^4e_g^2$
(c) Wavelength of light absorbed by [Co(en)₃]³⁺ is lower than that of [CoF₆]^3-
(d) If the $\Delta $₀ for an octahedral complex of CO(III) is 18,000 cm^-1, the $\Delta $_t for its tetrahedral complex with the same ligand be 16,000 cm^-1

(a) and (b) only

(b) and (c) only

(a) and (d) only

Question 195: Palette 195/274

JEE Mains 2020 MCQ

The theory that can completely/properly explain the nature of bonding in [Ni(Co)₄] is :

Wemer's theory

Valence bond theory

Crystal field theory

Molecular orbital theory

Question 196: Palette 196/274

JEE Mains 2020 MCQ

The IUPAC name of complex [Pt(NH₃)₂Cl(NH₂CH₃)]Cl is:

Diamminechlorido (methanamine) platinum(II)chloride.

Biasmmine (methanamine)chlorido platinum(II)chloride.

Diamminechlorido (amminomethane) platinum(II) chloride.

Diammine (methanamine) chlorido platinum(II)Chloride.

Question 197: Palette 197/274

JEE Mains 2019 MCQ

The compound used in the treatment of lead poisoning is :

desferrioxime B

Cis-platin

D-penicillamine

EDTA

Question 198: Palette 198/274

JEE Mains 2019 MCQ

The coordination numbers of Co and Al in [Co(Cl)(en)₂]Cl and K₃[Al(C₂O₄)₃], respectively, are : (en = ethane-1, 2-diamine)

3 and 3

6 and 6

5 and 3

5 and 6

Question 199: Palette 199/274

JEE Mains 2019 MCQ

Complete removal of both the axial ligands (along the z-axis) from an octahedral complex leads to which of the following splitting patterns? (relative orbital energies not on scale).

JEE Main 2019 (Online) 12th April Morning Slot Chemistry - Coordination Compounds Question 279 English Option 1

JEE Main 2019 (Online) 12th April Morning Slot Chemistry - Coordination Compounds Question 279 English Option 2

JEE Main 2019 (Online) 12th April Morning Slot Chemistry - Coordination Compounds Question 279 English Option 3

JEE Main 2019 (Online) 12th April Morning Slot Chemistry - Coordination Compounds Question 279 English Option 4

Question 200: Palette 200/274

JEE Mains 2019 MCQ

The complex ion that will lose its crystal field stabilization energy upon oxidation of its metal to +3 state is :

JEE Main 2019 (Online) 12th April Morning Slot Chemistry - Coordination Compounds Question 280 English

[Fe(phen)₃]²⁺

[Zn(phen)₃]²⁺

[Co(phen)₃]²⁺

[Ni(phen)₃]²⁺

Question 201: Palette 201/274

JEE Mains 2019 MCQ

The crystal field stabilization energy (CFSE) of [Fe(H₂O)₆]Cl₂ and K₂[NiCl₄] respectively, are :

– 0.4 $\Delta $₀ and – 0.8 $\Delta $_t

– 0.6 $\Delta $₀ and – 0.8 $\Delta $_t

– 2.4 $\Delta $₀ and – 1.2 $\Delta $_t

– 0.4 $\Delta $₀ and – 1.2 $\Delta $_t

Question 202: Palette 202/274

JEE Mains 2019 MCQ

The species that can have a trans-isomer is :
(en = ehane-1, 2-diamine, ox = oxalate)

[Cr(en)²(ox)]⁺

[Pt(en)Cl₂]

[Pt(en)₂Cl₂]²⁺

[Zn(en)Cl₂]

Question 203: Palette 203/274

JEE Mains 2019 MCQ

Three complexes,
[CoCl(NH₃)₅] ²⁺(I),
[Co(NH₃)₅H₂O]³⁺ (II) and
[Co(NH₃)₆] ³⁺(III)
absorb light in the visible region. The correct order of the wavelength of light absorbed by them is :

(III) > (I) > (II)

(III) > (II) > (I)

(I) > (II) > (III)

(II) > (I) > (III)

Question 204: Palette 204/274

JEE Mains 2019 MCQ

The maximum possible denticities of a ligand given below towards a common transition and inner-transition metal ion, respectively, are :

JEE Main 2019 (Online) 9th April Evening Slot Chemistry - Coordination Compounds Question 285 English

8 and 6

8 and 8

6 and 8

6 and 6

Question 205: Palette 205/274

JEE Mains 2019 MCQ

The correct statements among I to III are :
(I) Valence bond theory cannot explain the color exhibited by transition metal complexes.
(II) Valence bond theory can predict quantitatively the magnetic properties of transtition metal complexes.
(III) Valence bond theory cannot distinguish ligands as weak and strong field ones.

(II) and (III) only

(I) and (II) only

(I), (II) and (III)

(I) and (III) only

Question 206: Palette 206/274

JEE Mains 2019 MCQ

The one that will show optical activity is :
(en = ethane-1,2-diamine)

JEE Main 2019 (Online) 9th April Morning Slot Chemistry - Coordination Compounds Question 286 English Option 1

JEE Main 2019 (Online) 9th April Morning Slot Chemistry - Coordination Compounds Question 286 English Option 2

JEE Main 2019 (Online) 9th April Morning Slot Chemistry - Coordination Compounds Question 286 English Option 3

JEE Main 2019 (Online) 9th April Morning Slot Chemistry - Coordination Compounds Question 286 English Option 4

Question 207: Palette 207/274

JEE Mains 2019 MCQ

The degenerate orbitals of [Cr(H₂O)₆]³⁺ are :

d_x² and d_xz

d_xz and d_yz

d_yz and d_z²

d_{x² - y²} and d_xy

Question 208: Palette 208/274

JEE Mains 2019 MCQ

The compound that inhibits the growth of tumors is :

cis-[Pd(Cl)₂(NH₃)₂]

trans-[Pd(Cl)₂(NH₃)₂]

cis-[Pt(Cl)₂(NH₃)₂]

trans-[Pt(Cl)₂(NH₃)₂]

Question 209: Palette 209/274

JEE Mains 2019 MCQ

The calculated spin-only magnetic moments (BM) of the anionic and cationic species of [Fe(H₂O)₆]₂ and [Fe(CN)₆], respectively, are :

2.84 and 5.92

4.9 and 0

0 and 4.9

0 and 5.92

Question 210: Palette 210/274

JEE Mains 2019 MCQ

The correct order of the spin-only magnetic moment of metal ions in the following low-spin complexes, [V(CN)₆]^4–,[Fe(CN)₆]^4–, [Ru(NH₃)₆]³⁺, and [Cr(NH₃)₆]²⁺ , is :

V²⁺ > Ru³⁺ > Cr²⁺ > Fe²⁺

V²⁺ > Cr²⁺ > Ru³⁺ > Fe²⁺

Cr²⁺ > V²⁺ > Ru³⁺ > Fe²⁺

Cr²⁺ > Ru³⁺ > Fe²⁺ > V²⁺

Question 211: Palette 211/274

JEE Mains 2019 MCQ

The following ligand is : JEE Main 2019 (Online) 8th April Morning Slot Chemistry - Coordination Compounds Question 291 English

hexadentate

bidentate

tetradentate

tridentate

Question 212: Palette 212/274

JEE Mains 2019 MCQ

The magnetic moment of an octahedral homoleptic Mn(II) complex is 5.9 BM. The suitable ligand for this complex is -

CN^$-$

ethylenediamine

NCS^–

Question 213: Palette 213/274

JEE Mains 2019 MCQ

The metal d-orbitals that are directly facing the ligands in K₃[Co(CN)₆] are -

d_x²_$-$y² and d_z²

d_xy, d_xz and d_yz

d_xz, d_yz and d_z²

d_xy and d_{x² $-$ y²}

Question 214: Palette 214/274

JEE Mains 2019 MCQ

Mn₂(CO)₁₀ is an organometallic compound due to the presence of -

C–O bond

Mn – Mn bond

Mn – O bond

Mn – C bond

Question 215: Palette 215/274

JEE Mains 2019 MCQ

The pair of metal ions that can give a spin only magnetic moment of 3.9 BM for the complex [M(H₂O)₆]Cl₂, is -

V²⁺ and Fe²⁺

V²⁺ and Co²⁺

Co²⁺ and Fe²⁺

Cr²⁺ and Mn²⁺

Question 216: Palette 216/274

JEE Mains 2019 MCQ

The coordination number of Th in K₄[Th(C₂O₄)₄(OH₂)₂] is :
(C₂O${_4^{2 - }}$ = Oxalato)

Question 217: Palette 217/274

JEE Mains 2019 MCQ

The number of bridging CO ligand(s) and Co-Co bond(s) in Co₂(CO)₈, respectively are :

2 and 0

0 and 2

4 and 0

2 and 1

Question 218: Palette 218/274

JEE Mains 2019 MCQ

Match the metals (column I) with the coordination compound(s)/enzyme(s) (column II)

(Column I) Metals		(Column II) Coordination compounds(s) enzyme(s)
(A)	Co	(i)	Wilkinson catalyst
(B)	Zn	(ii)	Chlorophyl
(C)	Rh	(iii)	Vitamin B₁₂
(D)	Mg	(iv)	Carbonic anhydrase

(A)-(iii); (B)-(iv); (C)-(i); (D)-(ii)

(A)-(iv); (B)-(iii); (C)-(i); (D)-(ii)

(A)-(i); (B)-(ii); (C)-(iii); (D)-(iv)

(A)-(ii); (B)-(i); (C)-(iv); (D)-(iii)

Question 219: Palette 219/274

JEE Mains 2019 MCQ

A reaction of cobalt (III) chloride and ethylenediamine in a 1 : 2 mole ratio generates two isomeric products A (violet coloured) and B (green coloured). A can show optical activity, but B is optically inactive. What type of isomers does A and B represcent?

Ionisation isomers

Linkage isomers

Coordination isomers

Geometrical isomers

Question 220: Palette 220/274

JEE Mains 2019 MCQ

The difference in the number of unpaired electrons of a metal ion in its high spin and low-spin octahedral complexes is two. The metal ion is :

Mn²⁺

Ni²⁺

Co²⁺

Fe²⁺

Question 221: Palette 221/274

JEE Mains 2019 MCQ

The total number of isomers for a square planar complex
[M(F)(Cl)(SCN)(NO₂)] is

Question 222: Palette 222/274

JEE Mains 2019 MCQ

Homoleptic octahedral complexes of a metal ion 'M³⁺' with three monodenate ligands L₁, L₂ and L₃ adsorb wavelenths in the region of green, blue and red respectively. The increasing order of the ligands strength is :

L₃ < L₁ < L₂

L₃ < L₂ < L₁

L₁ < L₂ < L₃

L₂ < L₁ < L₃

Question 223: Palette 223/274

JEE Mains 2019 MCQ

The complex that has highest crystal field splitting energy ($\Delta $), is :

[Co(NH₃)₅(H₂O)]Cl₃

K₂[CoCl₄]

[Co(NH₃)₅Cl]Cl₂

K₃[Co(CN)₆]

Question 224: Palette 224/274

JEE Mains 2019 MCQ

Two complexes [Cr(H₂O)₆]Cl₃ (A) and [Cr(NH₃)₆]Cl₃ (B) are violet and yellow coloured, respectively. The incorrect statement regarding them is :

$\Delta $₀ values of (A) and (B) are calculated from the energies of violet and yellow light, respectively

both are paramagnetic with three unpaired electrons

both absorb energies corresponding to their complementry colors.

$\Delta $₀ value for (A) is less than that of (B).

Question 225: Palette 225/274

JEE Mains 2018 MCQ

Which of the following complexes will shows geometrical isomerism ?

aquachlorobis (ethylenediamine) cobalt (II) chloride

pentaaquachlorohromium (III) chloride

potassium amminetrichloropltinate (II)

potassium tris(oxalato) chromate (III)

Question 226: Palette 226/274

JEE Mains 2018 MCQ

In Wilkinson's catalyst, the hybridization of central metal ion and its shape are respectively :

sp³d, trigonal bipyramidal

sp³, tetrahedral

dsp², square planar

d²sp³, octahedral

Question 227: Palette 227/274

JEE Mains 2018 MCQ

Consider the following reaction and statements:
[Co(NH₃)₄Br₂]⁺ + Br^- $\to$ [Co(NH₃)₃Br₃] + NH₃
(I) Two isomers are produced if the reactant complex ion is a cis-isomer
(II) Two isomers are produced if the reactant complex ion is a trans-isomer
(III) Only one isomer is produced if the reactant complex ion is a trans-isomer
(IV) Only one isomer is produced if the reactant complex ion is a cis – isomer
The correct statements are

(II) and (IV)

(I) and (II)

(I) and (III)

(III) and (IV)

Question 228: Palette 228/274

JEE Mains 2018 MCQ

The oxidation states of Cr in [Cr(H₂O)₆]Cl₃, [Cr(C₆H₆)₂] and K₂[Cr(CN)₂(O)₂(O₂)(NH₃)] respectively are :

+3, 0 and +4

+3, +4 and +6

+3, +2 and +4

+3, 0 and +6

Question 229: Palette 229/274

JEE Mains 2018 MCQ

The total number of possible isomers for square-planar [Pt(Cl)(NO₂)(NO₃)(SCN)]^2- is :

Question 230: Palette 230/274

JEE Mains 2018 MCQ

The correct order of spin-only magnetic moments among the following is :
(Atomic number : Mn = 25, Co = 27, Ni = 28, Zn = 30)

[ZnCl₄]^2- > [NiCl₄]^2- > [CoCl₄]^2- > [MnCl₄]^2-

[CoCl₄]^2- > [MnCl₄]^2- > [NiCl₄]^2- > [ZnCl₄]^2-

[NiCl₄]^2- > [CoCl₄]^2- > [MnCl₄]^2- > [ZnCl₄]^2-

[MnCl₄]^2- > [CoCl₄]^2- > [NiCl₄]^2- > [ZnCl₄]^2-

Question 231: Palette 231/274

JEE Mains 2018 MCQ

The correct combination is :

[Ni(CN)₄]^2- $-$ tetrahedral ;

[Ni(CO)₄] $-$ paramagnetic

[Ni(Cl)₄]^2- $-$ paramagnetic ;

[Ni(CO)₄] $-$ tetrahedral

[Ni(Cl)₄]^2- $-$ square-planar ;

[Ni(CN)₄] ^2-$-$ paramagnetic

[Ni(Cl)₄]^2- $-$ diamagnetic ;

[Ni(CO)₄] $-$square-planar

Question 232: Palette 232/274

JEE Mains 2017 MCQ

[Co₂(CO)₈] displays :

one Co−Co bond, six terminal CO and two bridging CO

one Co−Co bond, four terminal CO and four bridging CO

no Co−Co bond, six terminal CO and two bridging CO

no Co−Co bond, four terminal CO and four bridging CO

Question 233: Palette 233/274

JEE Mains 2017 MCQ

On treatment of 100 mL of 0.1 M solution of CoCl₃. 6H₂O with excess AgNO₃; 1.2 $\times$ 10²² ions are precipitated. The complex is :

[Co(H₂O)₃Cl₃].3H₂O

[Co(H₂O)₆]Cl₃

[Co(H₂O)₅Cl]Cl₂.H₂O

[Co(H₂O)₄Cl₂]Cl.2H₂O

Question 234: Palette 234/274

JEE Mains 2016 MCQ

Which of the following is an example of homoleptic complex?

[Co(NH₃)₆]Cl₃

[Pt(NH₃)₂Cl₂]

[Co(NH₃)₄Cl₂]

[Co(NH₃)₅Cl]Cl₂

Question 235: Palette 235/274

JEE Mains 2016 MCQ

Which one of the following complexes will consume more equivalents of aqueous solution of Ag(NO₃)?

Na₃[CrCl₆]

[Cr(H₂O)₅Cl]Cl₂

[Cr(H₂O)₆]Cl₃

Na₂[CrCl₅(H₂O)]

Question 236: Palette 236/274

JEE Mains 2016 MCQ

Identify the correct trend given below : (Atomic No.=Ti : 22, Cr : 24 and Mo : 42)

$\Delta $^o of [Cr(H₂O)₆]²⁺ >

[Mo(H₂O)₆]²⁺ and

$\Delta $^o of [Ti(H₂O)₆]³⁺ > [Ti(H₂O)₆]²⁺

$\Delta $^o of [Cr(H₂O)₆]²⁺ >

[Mo(H₂O)₆]²⁺ and

$\Delta $^o of [Ti(H₂O)₆]³⁺ < [Ti(H₂O)₆]²⁺

$\Delta $^o of [Cr(H₂O)₆]²⁺

< [Mo(H₂O)₆]²⁺ and

$\Delta $^o of [Ti(H₂O)₆]³⁺ > [Ti(H₂O)₆]²⁺

$\Delta $^o of [Cr(H₂O)₆]²⁺

< [Mo(H₂O)₆]²⁺ and

$\Delta $^o of [Ti(H₂O)₆]³⁺ < [Ti(H₂O)₆]²⁺

Question 237: Palette 237/274

JEE Mains 2016 MCQ

The pair having the same magnetic moment is :
[At. No.: Cr = 24, Mn = 25, Fe = 26, Co = 27]

[Cr(H₂O)₆]²⁺ and [Fe(H₂O)₆]²⁺

[Mn(H₂O)₆]²⁺ and [Cr(H₂O)₆]²⁺

[CoCl₄]^2– and [Fe(H₂O)₆]²⁺

[Cr(H₂O)₆]²⁺ and [CoCl₄]^2–

Question 238: Palette 238/274

JEE Mains 2016 MCQ

Which one of the following complexes shows optical isomerism?
(en = ethylenediamine)

cis[Co(en)₂Cl₂]Cl

trans[Co(en)₂Cl₂]Cl

[Co(NH₃)₄Cl₂]Cl

[Co(NH₃)₃Cl₃]

Question 239: Palette 239/274

JEE Mains 2015 MCQ

Which of the following compounds is not colored yellow?

K₃[Co(NO₂)₆]

(NH₄)₃[As(Mo₃O₁₀)₄]

BaCrO₄

Zn₂[Fe(CN)₆]

Question 240: Palette 240/274

JEE Mains 2015 MCQ

The number of geometric isomers that can exist for square planar [Pt (Cl) (py) (NH₃) (NH₂OH)]+ is (py = pyridine) :

Question 241: Palette 241/274

JEE Mains 2014 MCQ

The equation which is balanced and represents the correct product(s) is :

[Mg (H₂O)₆ ]²⁺ + (EDTA)^4- $\buildrel {excess\,NaOH} \over \longrightarrow $ [Mg (EDTA) ]²⁺ + 6H₂O

CuSO₄ + KCN $\to$ K₂ [Cu (CN)₄] + K₂SO₄

Li₂O + 2KCl $\to$ 2LiCl + K₂O

[CoCl(NH₃)₅]⁺ + 5H⁺ $\to$ Co²⁺ + $5NH_4^+$ + Cl^-

Question 242: Palette 242/274

JEE Mains 2014 MCQ

The octahedral complex of a metal ion M³⁺ with four monodentate ligands L₁, L₂, L₃ and L₄ absorb wavelengths in the region of red, green, yellow and blue, respectively. The increasing order of ligand strength of the four ligands is :

L₃ < L₂ < L₄ < L₁

L₁ < L₂ < L₄ < L₃

L₄ < L₃ < L₂ < L₁

L₁ < L₃ < L₂ < L₄

Question 243: Palette 243/274

JEE Mains 2013 MCQ

Which of the following complex species is not expected to exhibit optical isomerism?

[Co (en)₂ Cl₂]^-

[Co (NH₃)₃ Cl₃]

[Co (en) (NH₃)₂ Cl₂]⁺

[Co (en)₃]³⁺

Question 244: Palette 244/274

JEE Mains 2012 MCQ

Which among the following will be named as dibromidobis (ethylene diamine) chromium(III) bromide?

[Cr (en)₃ ] Br₃

[Cr (en)₂ Br₂ ] Br

[Cr (en) Br₄ ]^-

[Cr (en) Br₂ ] Br

Question 245: Palette 245/274

JEE Mains 2011 MCQ

The magnetic moment (spin only) of [NiCl₄]²⁻ is

5.46 BM

2.82 BM

1.41 BM

1.82 BM

Question 246: Palette 246/274

JEE Mains 2011 MCQ

Which of the following facts about the complex [Cr (NH₃)₆ ]Cl₃ is wrong?

The complex is paramagnetic

The complex is an outer orbital complex

The complex gives white precipitate with silver nitrate solution

The complex involves d²sp³ hybridization and is octahedral in shape.

Question 247: Palette 247/274

JEE Mains 2010 MCQ

A solution containing 2.675g of CoCl₃. 6NH₃ (molar mass = 267.5 g mol^–1) is passed through a cation exchanger. The chloride ions obtained in solution were treated with excess of AgNO₃ to give 4.78 g of AgCl (molar mass = 143.5 g mol^–1). The formula of the complex is : (At. Mass of Ag = 108 u)

[Co(NH₃)₆]Cl₃

[CoCl₂(NH₃)₄]Cl

[CoCl₃(NH₃)₃]

[CoCl(NH₃)₅]Cl₂

Question 248: Palette 248/274

JEE Mains 2010 MCQ

Which one of the following has an optical isomer ?
(en = ethylenediamine)

[Zn (en) (NH₃)₂]²⁺

[Co (en)₃]³⁺

[Co (H₂O)₄ en]³⁺

[Zn (en)₂]²⁺

Question 249: Palette 249/274

JEE Mains 2009 MCQ

Which of the following has an optical isomer ?

[Co(en)(NH₃)₂]²⁺

[Co(H₂O)₄(en)]³⁺

[Co(en)₂(NH₃)₂]³⁺

[Co(NH₃)₃Cl]⁺

Question 250: Palette 250/274

JEE Mains 2009 MCQ

Which of the following pairs represents linkage isomers ?

[Pd (P Ph₃)₂ (NCS)₂] and [Pd (P Ph₃)₂ (SCN)₂]

[Co(NH₃)₅ NO₃]SO₄ and [Co(NH₃)₅ SO₄]NO₃

[Pt Cl₂(NH₃)₄] Br₂ and [Pt Br₂(NH₃)₄] Cl₂

[Cu (NH₃)₄] [Pt Cl₄] and [Pt (NH₃)₄] [CuCl₄]

Question 251: Palette 251/274

JEE Mains 2008 MCQ

In which of the following octahedral complexes of Co (at. no. 27), will the magnitude of $\Delta _o$ be the highest?

[Co(CN)₆]³⁻

[Co(C₂O₄)₃]³⁻

[Co(H₂O)₆]³⁺

[Co(NH₃)₆]³⁺

Question 252: Palette 252/274

JEE Mains 2008 MCQ

The coordination number and the oxidation state of the element ‘E’ in the complex [E(en)₂(C₂O₄)]NO₂ (where (en) is ethylene diamine) are, respectively,

6 and 2

4 and 2

4 and 3

6 and 3

Question 253: Palette 253/274

JEE Mains 2007 MCQ

Which one of the following has a square planar geometry?

[CoCl₄]^2-

[FeCl₄]^2-

[NiCl₄]^2-

[PtCl₄]^2-

Question 254: Palette 254/274

JEE Mains 2006 MCQ

How many EDTA (ethylenediaminetetraacetic acid) molecules are required to make an octahedral complex with a Ca²⁺ ion?

Six

Three

One

Two

Question 255: Palette 255/274

JEE Mains 2006 MCQ

In Fe(CO)₅, the Fe – C bond possesses :

π-character only

both $\sigma$ and π characters

ionic character

$\sigma$-character

Question 256: Palette 256/274

JEE Mains 2006 MCQ

Nickel (Z = 28) combines with a uninegative monodentate ligand X^– to form a paramagnetic complex [NiX₄]²⁻ . The number of unpaired electron(s) in the nickel and geometry of this complex ion are, respectively

one, tetrahedral

two, tetrahedral

one, square planar

two, square planar

Question 257: Palette 257/274

JEE Mains 2006 MCQ

The IUPAC name for the complex [Co(NO₂)(NH₃)₅]Cl₂ is

nitrito-N-pentaamminecobalt (III) chloride

nitrito-N-pentaamminecobalt (II) chloride

pentaammine nitrito-N-cobalt (II) chloride

pentaammine nitrito-N-cobalt (III) chloride

Question 258: Palette 258/274

JEE Mains 2005 MCQ

Which one of the following cyano complexes would exhibit the lowest value of paramagnetic behaviour?
(At. No. Cr = 24, Mn = 25, Fe = 26, Co = 27)

[Cr(CN)₆]^-3

[Mn(CN)₆]^-3

[Fe(CN)₆]^-3

[Co(CN)₆]^-3

Question 259: Palette 259/274

JEE Mains 2005 MCQ

The IUPAC name of the coordination compound K₃[Fe(CN)₆] is

Potassium hexacyanoferrate (II)

Potassium hexacyanoferrate (III)

Potassium hexacyanoiron (II)

Tripotassium hexcyanoiron (II)

Question 260: Palette 260/274

JEE Mains 2005 MCQ

Which of the following compounds shows optical isomerism?

[Cu(NH₃)₄]⁺²

[ZnCl₄]^-2

[Cr(C₂O₄)₃]^-3

[Co(CN)₆]^-3

Question 261: Palette 261/274

JEE Mains 2005 MCQ

The oxidation state of Cr in [Cr(NH₃)₄Cl₂]⁺ is :

Question 262: Palette 262/274

JEE Mains 2005 MCQ

The value of the ‘spin only’ magnetic moment for one of the following configurations is 2.84 BM. The correct one is :

d⁴ (in strong ligand field)

d⁴ (in weak ligand field)

d³ (in weak as well as in strong fields)

d⁵ (in strong ligand field)

Question 263: Palette 263/274

JEE Mains 2004 MCQ

The correct order of magnetic moments (spin only values in B.M.) among is :
(Atomic numbers: Mn = 25; Fe = 26, Co =27)

[MnCl₄]^2- > [CoCl₄]^-2 > [Fe(CN)₆]^-4

[Fe(CN)₆]^-4 > [CoCl₄]^2- > [MnCl₄]^2-

[Fe(CN)₆]^4- > [MnCl₄]^2- > [CoCl₄]^2-

[MnCl₄]^2- > [Fe(CN)₆]^4- > [CoCl₄]^2-

Question 264: Palette 264/274

JEE Mains 2004 MCQ

Among the properties (a) reducing (b) oxidising (c) complexing, the set of properties shown by CN^– ion towards metal species is :

c, a

b, c

a, b

a, b, c

Question 265: Palette 265/274

JEE Mains 2004 MCQ

Which one of the following complexes in an outer orbital complex?

[Fe(CN)₆]^4-

[Ni(NH₃)₆]²⁺

[Co(NH₃)₆]³⁺

[Mn(CN)₆]^4-

Question 266: Palette 266/274

JEE Mains 2004 MCQ

Which one the following has largest number of isomers? (R = alkyl group, en = ethylenediamine)

[Ru(NH₃)₄Cl₂]⁺

[Co(en)₂Cl₂]⁺

[Ir(PR₃)₂ H(CO)]²⁺

[Co(NH₃)₅Cl]²⁺

Question 267: Palette 267/274

JEE Mains 2004 MCQ

The coordination number of central metal atom in a complex is determined by :

the number of ligands around a metal ion bonded by sigma bonds

the number of only anionic ligands bonded to the metal ion

the number of ligands around a metal ion bonded by sigma and pi- bonds both

the number of ligands around a metal ion bonded by pi-bonds

Question 268: Palette 268/274

JEE Mains 2004 MCQ

Coordination compound have great importance in biological systems. In this context which of the following statements is incorrect?

Chlorophylls are green pigments in plants and contains calcium

Carboxypeptidase – A is an enzyme and contains zinc

Cyanocobalamin is B₁₂ and contains cobalt

Haemoglobin is the red pigment of blood and contains iron

Question 269: Palette 269/274

JEE Mains 2003 MCQ

In the coordination compound, K₄[Ni(CN)₄], the oxidation state of nickel is :

-1

Question 270: Palette 270/274

JEE Mains 2003 MCQ

One mole of the complex compound Co(NH₃)₅Cl₃, gives 3 moles of ions on dissolution in water. One mole of the same complex reacts with two moles of AgNO₃ solution to yield two moles of AgCl (s). The structure of the complex is :

[Co(NH₃)₃Cl₃]. 2NH₃

[Co(NH₃)₄Cl₂] Cl. NH₃

[Co(NH₃)₄Cl] Cl₂. NH₃

[Co(NH₃)₅Cl] Cl₂

Question 271: Palette 271/274

JEE Mains 2003 MCQ

Ammonia forms the complex ion [Cu(NH₃)₄]²⁺ with copper ions in alkaline solutions but not in acidic solutions. What is the reason for it?

In acidic solutions protons coordinate with ammonia molecules forming $NH^+_4$ ions and NH₃ molecules are not available

In alkaline solutions insoluble Cu(OH)₂ is precipitated which is soluble in excess of any alkali

Copper hydroxide is an amphoteric substance

In acidic solutions hydration protects copper ions.

Question 272: Palette 272/274

JEE Mains 2002 MCQ

The most stable ion is :

[Fe(OH)₃]^3-

[Fe(Cl)₆]^3-

[Fe(CN)₆]^3-

[Fe(H₂O)₆]³⁺

Question 273: Palette 273/274

JEE Mains 2002 MCQ

CH₃ - Mg - Br is an organometallic compound due to :

Mg - Br bond

C - Mg bond

C - Br bond

C - H bond

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