Coordination Compounds — JEE Main PYQs

Which of the following complexes will show coordination isomerism ?

A. $\mathrm{[Ag(NH_3)_2][Ag(CN)_2]}$

B. $\mathrm{[Co(NH_3)_6][Cr(CN)_6]}$

C. $\mathrm{[Co(NH_3)_6][Co(CN)_6]}$

D. $\mathrm{[Fe(NH_3)_6][Co(CN)_6]}$

E. $\mathrm{[Co(NH_3)_6][Fe(CN)_6]}$

Choose the correct answer from the options given below :

Match the LIST-I with LIST-II

List-I (Complex ion)	List-II (Calculated spin only magnetic moment (BM))
A. $\mathrm{[Cr(H_2O)_6]^{2+}}$	I. 3.87
B. $\mathrm{[Co(H_2O)_6]^{2+}}$	II. 5.92
C. $\mathrm{[Cu(H_2O)_6]^{2+}}$	III. 4.90
D. $\mathrm{[Mn(H_2O)_6]^{2+}}$	IV. 1.73

Choose the correct answer from the options given below:

Consider the metal complexes $\mathrm{[Ni(en)_3]^{2+}}$ (A), $\mathrm{[NiCl_4]^{2-}}$ (B) and $\mathrm{[Ni(NH_3)_6]^{2+}}$ (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.

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:

Given below are two statements:

Statement I: Each electron in $\mathrm{e_g}$ orbitals destabilizes the orbitals by $+0.6\ \Delta_o$ and each electron in the $\mathrm{t_{2g}}$ orbitals stabilizes the orbitals by $-0.4\ \Delta_o$ 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

Identify the correct statements from the following

A. $\mathrm{[Fe(C_2O_4)_3]^{3-}}$ is the most stable complex among $\mathrm{[Fe(OH)_6]^{3-}}$, $\mathrm{[Fe(C_2O_4)_3]^{3-}}$ and $\mathrm{[Fe(SCN)_6]^{3-}}$

B. The stability of $\mathrm{[Cu(NH_3)_4]^{2+}}$ is greater than that of $\mathrm{[Cu(en)_2]^{2+}}$

C. The hybridization of Fe in $\mathrm{K_4[Fe(CN)_6]}$ is $d^2sp^3$

D. $\mathrm{[Fe(NO_2)_3Cl_3]^{3-}}$ exhibits linkage isomerism

E. $\mathrm{NO_2^-}$ and $\mathrm{SCN^-}$ ligands are NOT ambidentate ligands

Choose the correct answer from the options given below :

The total number of unpaired electrons present in the $d^3$, $d^4$ (low spin), $d^5$ (high spin), $d^6$ (high spin) and $d^7$ (low spin) octahedral complex systems is ________.

Match the LIST-I with LIST-II

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

Choose the correct answer from the options given below:

Which of the following are true about the energy of the given d-orbitals of a tetrahedral complex?

A. $d_{xy} = d_{xz} > d_{x^2-y^2}$ B. $d_{xy} = d_{yz} > d_{z^2}$ C. $d_{x^2-y^2} > d_{z^2} > d_{xz}$ D. $d_{x^2-y^2} = d_{z^2} < d_{xz}$

Choose the correct answer from the given below:

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

A. $\mathrm{[NiCl_4]^{2-}}$ – $sp^3$, tetrahedral, paramagnetic

B. $\mathrm{[Ni(NH_3)_6]^{2+}}$ – $sp^3d^2$, octahedral, paramagnetic

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

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

Choose the correct answer from the options given below :

An excess of $\mathrm{AgNO_3}$ is added to 100 mL of a 0.05 M solution of tetraaquadichloridochromium (III) chloride. The number of moles of AgCl precipitated will be ________ $\times 10^{-3}$.

(Nearest integer)

Number of paramagnetic complexes among the following is __________.

$\mathrm{[MnBr_4]^{2-}}$, $\mathrm{[NiCl_4]^{2-}}$, $\mathrm{[Ni(CN)_4]^{2-}}$, $\mathrm{[Ni(CO)_4]}$, $\mathrm{[CoF_6]^{3-}}$, $\mathrm{[Fe(CN)_6]^{4-}}$, $\mathrm{[Mn(CN)_6]^{3-}}$, $\mathrm{[Ti(CN)_6]^{3-}}$, $\mathrm{[Cu(H_2O)_6]^{2+}}$, $\mathrm{[Co(C_2O_4)_3]^{3-}}$

Given below are two statements :

Statement (I) : In octahedral complexes, when $\Delta_o < P$ high spin complexes are formed. When $\Delta_o > P$ 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 :

A transition metal (M) among Mn, Cr, Co and Fe has the highest standard electrode potential ($\mathrm{M^{3+}/M^{2+}}$). It forms a metal complex of the type $\mathrm{[M(CN)_6]^{4-}}$. The number of electrons present in the $e_g$ orbital of the complex is __________.

The d-orbital electronic configuration of the complex among $\mathrm{[Co(en)_3]^{3+}}$, $\mathrm{[CoF_6]^{3-}}$, $\mathrm{[Mn(H_2O)_6]^{2+}}$ and $\mathrm{[Zn(H_2O)_6]^{2+}}$ that has the highest CFSE is :

The type of hybridization and the magnetic property of $\mathrm{[MnCl_6]^{3-}}$ are,

The correct order of the complexes $\mathrm{[Co(NH_3)_5(H_2O)]^{3+}}$ (A), $\mathrm{[Co(NH_3)_6]^{3+}}$ (B), $\mathrm{[Co(CN)_6]^{3-}}$ (C) and $\mathrm{[CoCl(NH_3)_5]^{2+}}$ (D) in terms of wavelength of light absorbed is

The number of optical isomers exhibited by the iron complex (A) obtained from the following reaction is __________.

$\mathrm{FeCl_3 + KOH + H_2C_2O_4 \rightarrow A}$

Identify the diamagnetic octahedral complex ions from below ;

A. $\mathrm{[Mn(CN)_6]^{3-}}$ B. $\mathrm{[Co(NH_3)_6]^{3+}}$ C. $\mathrm{[Fe(CN)_6]^{4-}}$ D. $\mathrm{[Co(H_2O)_3F_3]}$

Choose the correct answer from the options given below:

'X' is the number of electrons in $t_{2g}$ orbitals of the most stable complex ion among $\mathrm{[Fe(NH_3)_6]^{3+}}$, $\mathrm{[FeCl_6]^{3-}}$, $\mathrm{[Fe(C_2O_4)_3]^{3-}}$ and $\mathrm{[Fe(H_2O)_6]^{3+}}$. The nature of oxide of vanadium of the type $\mathrm{V_2O_X}$ is :

The correct order of $\mathrm{[FeF_6]^{3-}}$, $\mathrm{[CoF_6]^{3-}}$, $\mathrm{[Ni(CO)_4]}$ and $\mathrm{[Ni(CN)_4]^{2-}}$ complex species based on the number of unpaired electrons present is :

A metal complex with a formula $\mathrm{MCl_4.3NH_3}$ is involved in $sp^3d^2$ hybridisation. It upon reaction with excess of $\mathrm{AgNO_3}$ solution gives '$x$' moles of AgCl. Consider '$x$' is equal to the number of lone pairs of electron present in central atom of $\mathrm{BrF_5}$. Then the number of geometrical isomers exhibited by the complex is _________.

An octahedral complex having molecular composition $\mathrm{Co.5NH_3.Cl.SO_4}$ 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,

The number of paramagnetic complexes among $\mathrm{[FeF_6]^{3-}}$, $\mathrm{[Fe(CN)_6]^{3-}}$, $\mathrm{[Mn(CN)_6]^{3-}}$, $\mathrm{[Co(C_2O_4)_3]^{3-}}$, $\mathrm{[MnCl_6]^{3-}}$, and $\mathrm{[CoF_6]^{3-}}$, which involved $\mathrm{d^2sp^3}$ hybridization is ___________

'X' is the number of acidic oxides among $\mathrm{VO_2}$, $\mathrm{V_2O_3}$, $\mathrm{CrO_3}$, $\mathrm{V_2O_5}$ and $\mathrm{Mn_2O_7}$. The primary valency of cobalt in $\mathrm{[Co(H_2NCH_2CH_2NH_2)_3]_2(SO_4)_3}$ is Y. The value of $X + Y$ is __________.

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

$\mathrm{[Fe(CN)_6]^{3-}}$, $\mathrm{[FeF_6]^{3-}}$, $\mathrm{[CoF_6]^{3-}}$, $\mathrm{[Mn(CN)_6]^{3-}}$

Match List - I with List - II.

List - I (Complex)	List - II (Primary valency and Secondary valency)
(A) $\mathrm{[Co(en)_2Cl_2]Cl}$	(I) 3, 6
(B) $\mathrm{[Pt(NH_3)_2Cl(NO_2)]}$	(II) 3, 4
(C) $\mathrm{Hg[Co(SCN)_4]}$	(III) 2, 6
(D) $\mathrm{[Mg(EDTA)]^{2-}}$	(IV) 2, 4

Choose the correct answer from the options given below :

The number of paramagnetic metal complex species among $\mathrm{[Co(NH_3)_6]^{3+}}$, $\mathrm{[Co(C_2O_4)_3]^{3-}}$, $\mathrm{[MnCl_6]^{3-}}$, $\mathrm{[Mn(CN)_6]^{3-}}$, $\mathrm{[CoF_6]^{3-}}$, $\mathrm{[Fe(CN)_6]^{3-}}$ and $\mathrm{[FeF_6]^{3-}}$ with same number of unpaired electrons is __________.

The number of species from the following that are involved in $\mathrm{sp^3d^2}$ hybridization is

$\mathrm{[Co(NH_3)_6]^{3+}}$, $\mathrm{SF_6}$, $\mathrm{[CrF_6]^{3-}}$, $\mathrm{[CoF_6]^{3-}}$, $\mathrm{[Mn(CN)_6]^{3-}}$ and $\mathrm{[MnCl_6]^{3-}}$

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

Match the LIST-I with LIST-II

	LIST-I (Complex/ Species)		LIST-II (Shape & magnetic moment)
A.	$\mathrm{[Ni(CO)_4]}$	I.	Tetrahedral, 2.8 BM
B.	$\mathrm{[Ni(CN)_4]^{2-}}$	II.	Square planar, 0 BM
C.	$\mathrm{[NiCl_4]^{2-}}$	III.	Tetrahedral, 0 BM
D.	$\mathrm{[MnBr_4]^{2-}}$	IV.	Tetrahedral, 5.9 BM

Choose the correct answer from the options given below:

From the magnetic behaviour of $\mathrm{[NiCl_4]^{2-}}$ (paramagnetic) and $\mathrm{[Ni(CO)_4]}$ (diamagnetic), choose the correct geometry and oxidation state.

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

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

(A) $\mathrm{[Fe(CN)_5NO]^{2-}}$ (B) $\mathrm{[CoF_6]^{3-}}$ (C) $\mathrm{[Fe(CN)_6]^{4-}}$ (D) $\mathrm{[Co(NH_3)_6]^{3+}}$ (E) $\mathrm{[Cr(H_2O)_6]^{2+}}$

Choose the correct answer from the options given below :

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

The complex of $\mathrm{Ni^{2+}}$ ion and dimethyl glyoxime contains __________ number of Hydrogen (H) atoms.

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

The complex that shows Facial - Meridional isomerism is:

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

(A) $\mathrm{[FeO_4]^{2-}}$

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

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

(D) $\mathrm{Cr_2(O{-}\overset{\overset{\textstyle O}{\|}}{C}{-}Me)_4(H_2O)_2}$ (chromium(II) acetate dimer)

(E) $\mathrm{[NiF_6]^{2-}}$

Choose the correct answer from the options given below :

One mole of the octahedral complex compound $\mathrm{Co(NH_3)_5Cl_3}$ 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 $\mathrm{AgCl_{(s)}}$. The structure of the complex is:

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

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

Match List-I with List-II :

List-I (Complex)	List-II (Hybridisation of central metal ion)
(A) $\mathrm{[CoF_6]^{3-}}$	(I) $d^2sp^3$
(B) $\mathrm{[NiCl_4]^{2-}}$	(II) $sp^3$
(C) $\mathrm{[Co(NH_3)_6]^{3+}}$	(III) $sp^3d^2$
(D) $\mathrm{[Ni(CN)_4]^{2-}}$	(IV) $dsp^2$

Choose the correct answer from the options given below :

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

Number of complexes from the following with even number of unpaired "d" electrons is ________.

$\mathrm{[V(H_2O)_6]^{3+}, [Cr(H_2O)_6]^{2+}, [Fe(H_2O)_6]^{3+}, [Ni(H_2O)_6]^{3+}, [Cu(H_2O)_6]^{2+}}$

[Given atomic numbers : V = 23, Cr = 24, Fe = 26, Ni = 28 Cu = 29]

The number of unpaired d-electrons in $\mathrm{[Co(H_2O)_6]^{3+}}$ is ________.

If an iron (III) complex with the formula $\mathrm{\left[Fe(NH_3)_x(CN)_y\right]^-}$ has no electron in its $\mathrm{e_g}$ orbital, then the value of $x + y$ is

The correct order of ligands arranged in increasing field strength.

Which one of the following complexes will exhibit the least paramagnetic behaviour ?

[Atomic number, Cr = 24, Mn = 25, Fe = 26, Co = 27]

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

The number of complexes from the following with no electrons in the $\mathrm{t_2}$ orbital is ________.

$\mathrm{TiCl_4}$, $\mathrm{[MnO_4]^-}$, $\mathrm{[FeO_4]^{2-}}$, $\mathrm{[FeCl_4]^-}$, $\mathrm{[CoCl_4]^{2-}}$

Consider the following complexes

$\mathrm{[CoCl(NH_3)_5]^{2+}}$, $\mathrm{[Co(CN)_6]^{3-}}$, $\mathrm{[Co(NH_3)_5(H_2O)]^{3+}}$, $\mathrm{[Cu(H_2O)_4]^{2+}}$

(A)     (B)     (C)     (D)

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

The correct IUPAC name of $\mathrm{[PtBr_2(PMe_3)_2]}$ is :

Match List - I with List - II.

List - I (Tetrahedral Complex)	List - II (Electronic configuration)
(A) $\mathrm{TiCl_4}$	(I) $e^2, t_2^0$
(B) $\mathrm{[FeO_4]^{2-}}$	(II) $e^4, t_2^3$
(C) $\mathrm{[FeCl_4]^{-}}$	(III) $e^0, t_2^0$
(D) $\mathrm{[CoCl_4]^{2-}}$	(IV) $e^2, t_2^3$

Choose the correct answer from the options given below :

Given below are two statements:

Statement I: $\mathrm{N(CH_3)_3}$ and $\mathrm{P(CH_3)_3}$ can act as ligands to form transition metal complexes.

Statement II: As N and P are from same group, the nature of bonding of $\mathrm{N(CH_3)_3}$ and $\mathrm{P(CH_3)_3}$ is always same with transition metals.

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

An octahedral complex with the formula $\mathrm{CoCl_3 \cdot nNH_3}$ upon reaction with excess of $\mathrm{AgNO_3}$ solution gives 2 moles of AgCl. Consider the oxidation state of Co in the complex is 'x'. The value of "x + n" is _________.

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

$\mathrm{[Fe(H_2O)_6]^{2+}, [Co(H_2O)_6]^{2+}, [Co(H_2O)_6]^{3+}, [Cu(H_2O)_6]^{2+}, [Cr(H_2O)_6]^{2+}}$

Match List - I with List - II.

List - I (Complex ion)	List - II (Spin only magnetic moment in B.M.)
(A) $\mathrm{[Cr(NH_3)_6]^{3+}}$	(I) 4.90
(B) $\mathrm{[NiCl_4]^{2-}}$	(II) 3.87
(C) $\mathrm{[CoF_6]^{3-}}$	(III) 0.0
(D) $\mathrm{[Ni(CN)_4]^{2-}}$	(IV) 2.83

Choose the correct answer from the options given below :

Total number of unpaired electrons in the complex ions $\mathrm{[Co(NH_3)_6]^{3+}}$ and $\mathrm{[NiCl_4]^{2-}}$ is ________.

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 $\mathrm{[Co(en)_2Cl_2]^+}$ complex ion is three. Reason (R) : $\mathrm{[Co(en)_2Cl_2]^+}$ complex ion has an octahedral geometry. In the light of the above statements, choose the most appropriate answer from the options given below :

Number of ambidentate ligands among the following is ________. $$\mathrm{NO_2^-,\ SCN^-,\ C_2O_4^{2-},\ NH_3,\ CN^-,\ SO_4^{2-},\ H_2O}.$$

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

Match List I with List II

	LIST I		LIST II
A.	$\mathrm{K_2[Ni(CN)_4]}$	I.	$\mathrm{sp^3}$
B.	$\mathrm{[Ni(CO)_4]}$	II.	$\mathrm{sp^3d^2}$
C.	$\mathrm{[Co(NH_3)_6]Cl_3}$	III.	$\mathrm{dsp^2}$
D.	$\mathrm{Na_3[CoF_6]}$	IV.	$\mathrm{d^2sp^3}$

Choose the correct answer from the options given below:

Given below are two statements :

Statement (I) : A solution of $\mathrm{[Ni(H_2O)_6]^{2+}}$ is green in colour.

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

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

Which of the following complex is homoleptic ?

$\mathrm{[Co(NH_3)_6]^{3+}}$ and $\mathrm{[CoF_6]^{3-}}$ are respectively known as :

Consider the following complex ions

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

$\mathrm{Q = [V(H_2O)_6]^{2+}}$

$\mathrm{R = [Fe(H_2O)_6]^{2+}}$

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

In which one of the following metal carbonyls, CO forms a bridge between metal atoms?

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: