Question 1

According to crystal field theory, the correct order of ligands with respect to their decreasing order of field strength is

Accepted Answer

According to the spectrochemical series, the arrangement of ligands in the increasing order of their crystal field splitting energy (CFSE) or field strength is: I ^- From the given ligands, the decreasing order of field strength is: CO > NH _3 > H _2 O > Cl ^- Answer: CO > NH _3> H _2 O > Cl ^-

Question 2

Match List I with List II : List I (Complex/ion) List II (Shape/geometry) A. [ Pt ( Cl _2)( NH _3)_2] I. Octahedral B. [ Co ( NH _3)_6] Cl _3 II. Trigonal bipyramidal C. [ NiCl _4]^ 2- III. Square pla

Accepted Answer

For [ Pt ( Cl _2)( NH _3)_2], Pt is in +2 oxidation state. Pt(II) complexes are generally square planar with dsp^2 hybridization. For [ Co ( NH _3)_6] Cl _3, Co is in +3 oxidation state. With a coordination number of 6, it forms an octahedral geometry. For [ NiCl _4]^ 2- , Ni is in +2 oxidation state (3d^8). Since Cl ^- is a weak field ligand, no pairing of electrons occurs, resulting in sp^3 hybridization and a tetrahedral geometry. For [ Fe ( CO )_5], Fe is in 0 oxidation state. With a coordin

Question 3

The formula of tetraammineaquachloridocobalt(III) chloride is

Accepted Answer

The complex name is tetraammineaquachloridocobalt(III) chloride. The central metal ion is cobalt(III), which means Co is in the +3 oxidation state. The ligands inside the coordination sphere are four ammine ( NH _3) molecules which are neutral, one aqua ( H _2 O ) molecule which is neutral, and one chlorido ( Cl ^-) ion which has a -1 charge. The coordination sphere is [ Co ( NH _3)_4( H _2 O ) Cl ]. The charge on the complex ion is calculated as +3 + 4(0) + 0 + (-1) = +2. To balance the +2 char

Question 4

Match List I with List II : List I (Complex) List II (Type of isomerism) A. [ Pt ( NH _3)_2 Cl _2] I. Optical B. [ Co ( en )_3]^ 3+ II. Solvate C. [ Co ( NH _3)_5 NO _2] Cl _2 III. Geometrical D. [ Cr

Accepted Answer

A. [ Pt ( NH _3)_2 Cl _2] is a square planar complex of the type MA_2B_2. It exhibits geometrical isomerism (cis and trans forms). B. [ Co ( en )_3]^ 3+ is an octahedral complex with three symmetrical bidentate ligands. It lacks a plane of symmetry and exhibits optical isomerism. C. [ Co ( NH _3)_5 NO _2] Cl _2 contains the ambidentate ligand NO _2^-, which can coordinate through either the nitrogen or oxygen atom. It exhibits linkage isomerism. D. [ Cr ( H _2 O )_6] Cl _3 can exchange water mol

Question 5

Given below are two statements: Statement-I : [ Fe(ox) _3]^ 3- is chiral. Statement-II : trans -[ Cr(H _2 O )_2( ox )_2]^- is chiral. (Given : oxH_2 = HOOC-COOH) In light of the above statements, choo

Accepted Answer

Statement-I: [ Fe(ox) _3]^ 3- is an octahedral complex of the type [M(AA)_3]. It lacks any plane of symmetry or center of inversion. Hence, it is optically active and chiral. Statement-I is correct. Statement-II: trans -[ Cr(H _2 O )_2( ox )_2]^- is an octahedral complex of the type trans -[M(AA)_2a_2]. In the trans isomer, the two identical monodentate ligands are placed opposite to each other. This geometry possesses a plane of symmetry passing through the metal and the bidentate ligands, as w

Question 6

The complex which has facial and meridional isomers is (Given : py = pyridine and en = H_2N-CH_2-CH_2-NH_2)

Accepted Answer

Facial and meridional isomerism is exhibited by octahedral complexes of the type [MA_3B_3]. [ Ni(en) _2( H _2 O )_2]^ 2+ is of the type [M(AA)_2B_2], which shows cis and trans isomerism. [ Cr(py) _3( Cl )_3] is of the type [MA_3B_3], which shows facial (fac) and meridional (mer) isomerism. [ Cr(H _2 O )_6]^ 3+ is of the type [MA_6], which does not show geometrical isomerism. [ Co(NH _3)_4( H _2 O )_2]^ 3+ is of the type [MA_4B_2], which shows cis and trans isomerism. Answer: [ Cr(py) _3( Cl )_3]

Question 7

Among the species given below, the spin-only magnetic moment is highest for (Given : Atomic number of Ti =22, Mn =25, Fe =26 and Co =27)

Accepted Answer

The spin-only magnetic moment is given by = n(n+2) BM, where n is the number of unpaired electrons. We determine n for each complex: For [ Ti(H _2 O )_6]^ 3+ : Ti is in +3 oxidation state. The electronic configuration of Ti^ 3+ is [ Ar ] 3d^1. Number of unpaired electrons, n = 1. = 1(1+2) = 3 BM. For [ Mn(CN) _6]^ 3- : Mn is in +3 oxidation state. The electronic configuration of Mn^ 3+ is [ Ar ] 3d^4. Since CN^- is a strong field ligand, pairing of electrons takes place. The configuration in the

Question 8

A 1:3 electrolyte in an aqueous solution is

Accepted Answer

A 1:3 electrolyte dissociates in an aqueous solution to give one cation and three anions, or vice versa, producing a total of four ions per formula unit. [ Co(NH _3)_3( NO _2)_3] is a neutral complex and does not dissociate into ions. It is a non-electrolyte. [ CoCl _2( NH _3)_4] Cl [ CoCl _2( NH _3)_4]^ + + Cl ^ - (1:1 electrolyte) [ CoCl(NH _3)_5] Cl _2 [ CoCl(NH _3)_5]^ 2+ + 2 Cl ^ - (1:2 electrolyte) [ Co(NH _3)_6] Cl _3 [ Co(NH _3)_6]^ 3+ + 3 Cl ^ - (1:3 electrolyte) Thus, [ Co(NH _3)_6] Cl

Question 9

Which one of the following is an ambidentate ligand ?

Accepted Answer

An ambidentate ligand is a unidentate ligand that has more than one donor atom but coordinates to the central metal atom or ion through only one donor atom at a time. Thiocyanate ion (SCN^ - or NCS^ - ) has two donor atoms, sulfur (S) and nitrogen (N). It can bind to the metal through either the sulfur atom (thiocyanato) or the nitrogen atom (isothiocyanato). Thus, it is an ambidentate ligand. Ethane-1,2-diamine is a bidentate ligand. Ethylenediaminetetraacetate ion is a hexadentate ligand. Oxal

Question 10

Which of the following are paramagnetic? A. [ NiCl _4 ]^ 2- B. Ni ( CO )_4 C. [ Ni ( CN )_4 ]^ 2- D. [ Ni ( H _2 O )_6 ]^ 2+ E. Ni ( PPh _3 )_4 Choose the correct answer from the options given below :

Accepted Answer

(A) [ NiCl _4 ]^ 2- Oxidation state =+2 Electronic configuration =3 d^8 4 s^0 Cl = W.F.L. No Pairing (D) [ Ni ( H _2 O )_6 ]^ 2+ Oxidation state =+2, configuration =3 ~d ^8 H _2 O is W.F.L. No pairing Hence both are paramagnetic.

Question 11

Match List-I with List-II array |l|l|l|l| & List - I & & List - II \ A . & Haber process & (i) & Fe catalyst \ B. & Wacker oxidation & (ii) & PdCl _2 \ C. & Wilkinson catalyst & (iii) & [ ( PPh _3

Accepted Answer

Catalyst according to NCERT.

Question 12

The correct order of the wavelength of light absorbed by the following complexes is, A. [ Co ( NH _3 )_6 ]^ 3+ B. [ Co ( CN )_6 ]^ 3- C. [ Cu ( H _2 O )_4 ]^ 2+ D. [ Ti ( H _2 O )_6 ]^ 3+ Choose the c

Accepted Answer

Answer option index: 1

Question 13

Out of the following complex compounds, which of the compound will be having the minimum conductance in solution?

Accepted Answer

Both (1) & (2) are non-electrolytes that's why they show minimum conductivity among following options.

Question 14

Which of the following is not an ambidentate ligand?

Accepted Answer

Ambidentate ligands are those ligands which have two different donor atoms and either of two donor atom is attached to the metal during complex formation. (1) COO ^ - M has only one donor site through ' O '. So, it is not ambidentate. (2) SCN M NCS M (Ambidentate)

Question 15

[ Mn _2( CO )_ 10 ] and [ Co _2( CO )_8 ] structures have A. Metal-Metal linkage B. Terminal CO groups C. Bridging CO groups D. Metal in zero oxidation state Choose the correct answer from the options

Accepted Answer

A. Metal-Metal linkage present. B. Terminal CO groups are present C. In [ Mn _2( CO )_ 10 ] bridging CO groups are not present. D. Metal is in zero oxidation state.

Question 16

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

Accepted Answer

Answer option index: 3

Question 17

Given below are two statements : Statement I: Both [ Co ( NH _3 )_6 ]^ 3+ and [ CoF _6 ]^ 3- complexes are octahedral but differ in their magnetic behaviour. Statement II: [ Co ( NH _3 )_6 ]^ 3+ is di

Accepted Answer

In [ Co ( NH _3 )_6 ]^ 3+ , Co ^ 3+ ion is having 3 ~d ^6 configuration. Electronic configuration of Co ^ 3+ : In presence of NH _3 ligand, pairing of electrons takes place and it becomes diamagnetic complex ion. In presence of NH _3 ligand : [ Co ( NH _3 )_6 ]^ 3+ is octahedral with d ^2 sp ^3 hybridisation and it is diamagnetic in nature. In case of [ CoF _6 ]^ 3- , Co is in +3 oxidation state and it is having 3 ~d ^6 configuration. In presence of weak field F ^ - ligand, pairing does not take

Question 18

Given below are two statements : Statement I : [ Co ( NH _3 )_6 ]^ 3+ is a homoleptic complex whereas [ Co ( NH _3 )_4 Cl _2 ]^ + is a heteroleptic complex. Statement II : Complex [ Co ( NH _3 )_6 ]^

Accepted Answer

[ Co ( NH _3 )_6 ]^ 3+ is a homoleptic complex as only one type of ligands ( NH _3 ) is coordinated with Co ^ 3+ ion. While [ Co ( NH _3 )_4 Cl _2 ]^ + is a heteroleptic complex in which Co ^ 3+ ion is ligated with more than one type of ligands, i.e., NH _3 and Cl ^ - .

Question 19

Ethylene diaminetetraacetate ion is a/an:

Accepted Answer

It is hexadentate as it can bind through two nitrogen and four oxygen atoms to a central metal ion.

Coordination Compounds — Previous Year Questions & Solutions