Coordination Compounds

ALLEN - INDIRANAGAR
Coordination Compounds DPP-01

1. Some salts although containing two different metallic elements give test for one of them in solution.
Such salts are
(A) complex salt
(B) double salt
(C) normal salt
(D) none of these

2. Aqueous solution of 𝐅𝐞𝐒𝐎𝟒 gives tests for both 𝐅𝐞𝟐 and 𝐒𝐎𝟐𝟒 but after addition of excess of KCN,
solution ceases to give test for 𝐅𝐞𝟐 . This is due to the formation of
(A) the double salt FeSO . 2KCN. 6H O
(B) Fe(CN)
(C) the complex ion [Fe(CN) ]
(D) the complex ion [Fe(CN) ]

3. Which of the following statements is incorrect ?

(A) Coordination compounds and complexes are synonymous terms.
(B) Complexes must give ions in the solution.
(C) Complexes may give ions in the solution or may not give ions in the solution.
(D) Generally complex ion does not dissociate into its component parts even in the solution.

4. Which of the following complexes formed by 𝐂𝐮𝟐 ions is most stable ?

(A) Cu + 4NH ⇌ [Cu(NH ) ] , log K = 11.6
(B) Cu + 4CN ⇌ [Cu(CN) ] , log K = 27.3
(C) Cu + 2en ⇌ [Cu(en) ] , log K = 15.4
(D) Cu + 4H O ⇌ [Cu(H O) ] , log K = 8.9

5. The coordination number of Cr in the complex ion [𝐂𝐫(𝐇𝟐 𝐎)𝟔 ]𝟑 is :-

(A) Zero
(B) 3
(C) 6
(D) None of these

6. All ligands are :-

(A) Lewis acid
(B) Lewis base
(C) Neutral
(D) None of these

[1]
Coordination Compounds

7. The coordination number of cobalt in [𝐂𝐨(𝐞𝐧)𝟐 𝐁𝐫𝟐 ]𝐂𝐥𝟐 is :-

(A) 2
(B) 4
(C) 6
(D) 8

8. These questions contains, Statement-I (assertion) and Statement-II (reason).

Statement-I : 𝐊 𝟐 𝐒𝐎𝟒 . 𝐀𝐥𝟐 (𝐒𝐎𝟒 )𝟑 . 𝟐𝟒𝐇𝟐 𝐎 is a double salt compound.
Because
Statement-II : It ionises to give a complex ion.
(A) Statement-I is True, Statement-II is True ; Statement-II is a correct explanation for Statement-I
(B) Statement-I is True, Statement-II is True ; Statement-II is NOT a correct explanation for Statement-I
(C) Statement-I is True, Statement-II is False.
(D) Statement-I is False, Statement-II is True.

9. Which is TRUE about metal complex ?

(A) Central metal acts as lewis acid
(B) Ligands acts lewis base
(C) It will give test of all individual entities in aqueous solution
(D) The coordinate bonds are present in the metal complex

10. Which of the following complexes is/are an example of homoleptic complex ?

(A) [PtCl ]–
(B) K [Fe(CN) ]
(C) [Cr(NH ) Cl ]
(D) [CoBr (en) ]⊕

11. Which of the following complexes is/are an example of heteroleptic complex ?

(A) [Co(NO ) (NH ) ]
(B) K [Cr(NH ) ] (SO )
(C) [Co(NH ) Cl ]
(D) [Cr(C O ) ]–

12. In the coordination compound 𝐊 𝟒 [𝐍𝐢(𝐂𝐍)𝟒 ], the oxidation state of nickel is –

(A) 0
(B) +1
(C) +2
(D) –1

[2]
Coordination Compounds

13. Find the number of correct statement(s) is/are :-

(I) Both double salts as well as complexes are formed by the combination of two or more stable compounds
in stoichiometric ratio
(II) double salts such as carnallite, KCl. MgCl . 6H O, potash alum, KAl(SO ) . 12H O, etc. dissociate into simple
ions completely when dissolved in water
(III) complex ions such as [Fe(CN) ] of K [Fe(CN) ], do not dissociate into Fe and CN – ions
(IV) Mohr’s salt, FeSO . (NH ) SO . 6H O does not, dissociate into simple ions completely when dissolved in
water
(V) [CoCl (NH ) ]Cl complex dissociate into Co and Cl– ions

14. What is the coordination number of the central metal ions in the following complexes :
(i) [𝐂𝐮(𝐍𝐇𝟑 )𝟒 ]𝟐 (ii) [𝐅𝐞(𝐂𝟐 𝐎𝟒 )𝟑 ]𝟑 (iii) [𝐏𝐭 𝐂𝐥𝟐 (𝐞𝐧)𝟐 ] 𝟐
(iv) [𝐌𝐨(𝐂𝐍)𝟔 ]𝟒 (v) [𝐅𝐞(𝐄𝐃𝐓𝐀)]– (vi) [𝐏𝐝 𝐈𝟐 (𝐎𝐍𝐎)𝟐 (𝐇𝟐 𝐎)𝟐 ]

[3]
Coordination Compounds

Answer Key

Question 1 2 3 4 5 6 7 8 9 10 11 12 13 14
Answer A C B B C B C C A,B,D A,B A,C A 3 (i) →4,
(ii) →,
(iii) →,
(iv) →,
(v) →,
(iv) →

[4]
Coordination Compounds

ALLEN - INDIRANAGAR
Coordination Compounds DPP-02

1. Bidentate ligand is :-
(A) CN –
(B) Ethylene diamine
(C) EDTA
(D) SCN –

2. Triphenyl phosphine is :-
(A) Neutral and monodentate ligand
(B) Neutral and tridentate ligand
(C) Uninegative and unidentate ligand
(D) Trinegative and tridentate ligand

3. The total number of monodentate Ligands attached to the central metal ion through coordinate (sigma)
bond is called.
(A) Valency of the metal ion
(B) Oxidation state of the metal ion
(C) Coordination number of metal ion
(D) None of the above

4. Which of the following ligand does not act as bidentate ligand

(A) dipy
(B) dien
(C) gly –
(D) dmg –

5. Match each coordination compound in List-I with co-ordination number of central metal/ion from
List-II and select the correct answer using the code given below the lists.
List-I List-II
(P) [𝐂𝐨(𝐞𝐧)𝟑 ] 𝟑
(1) 6
(Q) [𝐂𝐚(𝐄𝐃𝐓𝐀)] 𝟐
(2) 4
(R) [𝐍𝐢(𝐂𝐎)𝟒 ] (3) 2
(S) [𝐀𝐠(𝐍𝐇𝟑 )𝟐 ]𝐂𝐥 (4) 5
(A) P → (1), Q → (3), R → (2), S → (3)
(B) P → (1), Q → (1), R → (2), S → (3)
(C) P → (2), Q → (1), R → (2), S → (2)
(D) P → (2), Q → (2), R → (3), S → (2)

6. Diethylene triamine is:

(A) Chelating agent
(B) Polydentate ligand
(C) Tridentate ligand
(D) All of these

[7]
Coordination Compounds


7. CN is an ambidentate ligand because
(A) it has multiple bonds
(B) carbon as a negative charge
(C) it form chelate
(D) both C & N can donate lone pair

8. Match the List with multiple options

List-I List-II
(P) Ethane 1, 2 diamine (1) Chelating agent
(Q) 𝐒𝐂𝐍¯ (2) Ambidentate
(R) 𝐂𝐎𝟐𝟑 (3) Flexidentate
(S) 𝐍𝐎𝟐 (4) Tridentate
(A) P-1; Q-2; R-3; S-4
(B) P-1; Q-2; R- 3; S-2
(C) P-4; Q-1; R- 3; S-2
(D) P-4; Q-1; R- 2; S-4

9. Which of the following is not considered as an organometallic compound ?

(A) Ferrocene
(B) Cis-platin
(C) Ziese's salt
(D) Grignard reagent

10. Statement-1 : In Zeise's salt C – C bond order regarding ethylene molecule is less than two.
Statement-2 : Ethylene accepts electron pair from filled d-orbital of 𝐏𝐭 𝟐 into its vacant bonding M.O.
(A) Statement-1 is true, statement-2 is true and statement-2 is correct explanation for statement-1.
(B) Statement-1 is true, statement-2 is true and statement-2 is NOT the correct explanation for statement-1.
(C) Statement-1 is true, statement-2 is false.
(D) Statement-1 is false, statement-2 is true.

11. Which of the following chemical species can act as non-classical ligand(s)
(A) CO
(B) C2H4
(C) NO+
(D) PR3

12. Which of the following bidentate ligand(s) has similar donor atoms :
(A) py
(B) bn
(C) en
(D) gly¯

[8]
Coordination Compounds

13. Find the number of ligands which behave predominantly as 𝛑-donor ligand (as well as non-classical
ligand)
𝐂𝟐 𝐇𝟒 , 𝐂𝟔 𝐇𝟔 , 𝐍𝐎 , 𝐍𝐎, 𝐂𝐎, 𝐍𝐇𝟑 , 𝐍𝐇𝟐 , 𝐇𝟐 𝐎, 𝐎𝐇

14. Find the total number of 5-membered rings present in [𝐂𝐨(𝐄𝐃𝐓𝐀)]– .

15. Find the number of complex(es) which have at least one five member chelate ring formed by two carbon
atoms, two nitrogen atoms and one central metal.
(I) [Co (EDTA)]– (II) [Co(en) ] (III) [Co (Gly) ] (IV) [Co (bipy) ]
(V) [Co(oxalate) ]– (VI) [Co (dien)(NH ) ]

[9]
Coordination Compounds

Answer Key

Question 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Answer B A C B B D D B B C A,B,C,D B,C 2 5 4

[10]
Coordination Compounds

ALLEN - INDIRANAGAR
Coordination Compounds DPP-03

1. Which of the following order is correct for the IR vibrational frequency of CO.
(A) [Fe(CO) ] < [Co(CO) ]– < [Ni(CO) ]
(B) [Fe(CO) ] > [Co(CO) ]– > [Ni(CO) ]
(C) [Fe(CO) ] > [Co(CO) ]– < [Ni(CO) ]
(D) [Fe(CO) ] < [Co(CO) ]– > [Ni(CO) ]

2. In the isoelectronic series of metal carbonyl, the C–O bond strength is expected to increase in the order.
(A) [Mn (CO) ] < [Cr(CO) ] < [V(CO) ]–
(B) [V(CO) ]– < [Cr(CO) ] < [Mn (CO) ]
(C) [V(CO) ]– < [Mn(CO) ] < [Cr(CO) ]
(D) [Cr (CO) ] < [Mn(CO) ] < [V(CO) ]–

3. The V–C distance in 𝐕(𝐂𝐎)𝟔 and [𝐕(𝐂𝐎)𝟔 ]– are respectively (in pm)-
(A) 200, 200
(B) 193, 200
(C) 200, 193
(D) 193, 193

4. Which of the following complex has highest M – C bond order ?

(A) [Mn(CO) ]
(B) [V(CO) ]–
(C) [Cr(CO) ]
(D) [Ti(CO) ]

5. Select the incorrect statement about metal carbonyl complex compounds :

(A) Metal carbon bond in metal carbonyls possess both s and p character
(B) Due to synergic bonding metal carbon bond becomes weak
(C) Due to synergic bonding carbon oxygen bond strength decreases
(D) In metal carbonyls extent of synergic bonding will increase with increase in negative charge on central metal ion

6. Consider the following statements:

According the Werner's theory.
(a) Ligands are connected to the metal ions by covalent bonds.
(b) Secondary valencies have directional properties
(c) Secondary valencies are non-ionisable
Of these statements:
(A) a, b and c are correct
(B) b and c are correct
(C) a and c are correct
(D) a and b are correct

[13]
Coordination Compounds

7. A complex of platinum, ammonia and chloride produces four ions per molecule in the solution. The
structure consistent with the observation is :
(A) [Pt(NH ) ]Cl
(B) [Pt(NH ) Cl ]
(C) [Pt(NH ) Cl]Cl
(D) [Pt(NH ) Cl ]Cl

8. Which of the following Werner’s complex has least electrical conductivity ?

(A)

(B)

(C)

(D)

[14]
Coordination Compounds

9. A co-ordination complex of cobalt has molecular formula containing five ammonia molecules, one nitro
group and two chlorine atoms for one cobalt atom. One mole of this compound produces three mole
ions in an aqueous solution. In reacting this solution with excess of silver nitrate solution, two moles of
AgCl get precipitated. The ionic formula of this complex would be :-
(A) [Co(NH ) . NO Cl]. [(NH )Cl]
(B) [Co(NH ) Cl]. [Cl(NO )]
(C) [Co(NH ) (NO )]Cl
(D) [Co(NH ) ]. [(NO ) Cl ]

10. Which of the following complex will give white precipitate with barium chloride solution :-
(A) [Cr(NH ) Cl]SO
(B) [Cr(NH )SO ]Cl
(C) [Co(NH ) ]Br
(D) None of these

11. Which of the following has least conductivity in aqueous solution.

(A) CoCl . 4NH
(B) CoCl . 3NH
(C) CoCl . 5NH
(D) CoCl . 6NH

12. Which gives only 25% mole of AgCl, when reacts with 𝐀𝐠𝐍𝐎𝟑 :-
(A) PtCl . 4NH
(B) PtCl . 5NH
(C) PtCl . 4NH
(D) PtCl . 3NH

13. Number of electrolytes in the complex 𝐂𝐨𝐂𝐥𝟑 . 𝟓𝐍𝐇𝟑

(A) 3
(B) 2
(C) 4
(D) 5

Match the list :

14. List-I List-II

[Species] [Stretching frequency of 𝐂𝐎 (𝐜𝐦–𝟏 )]

(P) 𝐂𝐎 (1) 2143

(Q) 𝐂𝐫(𝐂𝐎)𝟔 (2) 2000
(R) [𝐕(𝐂𝐎)𝟔 ] (3) 1860

(S) [𝐌𝐧(𝐂𝐎)𝟔 ] (4) 2090

(A) P -1; Q-2; R-3; S-4

(B) P -2 ; Q-1; R-3; S-4

(C) P -3 ; Q-1; R-2; S-4

(D) P -4; Q-1; R-3; S-2

[15]
Coordination Compounds

15. Match List I with List II and select the correct answer using the codes given below the lists :-
List I (Equivalent) List II
(conductance) (Formula)
A. 229 i. [𝐏𝐭(𝐍𝐇𝟑 )𝟓 𝐂𝐥]𝐂𝐥𝟑
B. 97 ii. [𝐏𝐭(𝐍𝐇𝟑 )𝟑 𝐂𝐥𝟑 ]𝐂𝐥
C. 404 iii. [𝐏𝐭(𝐍𝐇𝟑 )𝟒 𝐂𝐥𝟐 ]𝐂𝐥𝟐
D. 523 iv. [𝐏𝐭(𝐍𝐇𝟑 )𝟔 ]𝐂𝐥𝟒
(A) A-iii; B-i; C-iii; D-iv
(B) A-i; B-iv; C-iii; D-ii
(C) A-i; B-iii; C-iv; D-ii
(D) A-iii; B-ii; C-i; D-iv

Answer Key

Question 1 2 3 4 5 6 7 8 9 10
Answer A B C D B B C C C A
Question 11 12 13 14 15
Answer B D A A D

[16]
Coordination Compounds

ALLEN - INDIRANAGAR
Coordination Compounds DPP-04

1. The complex that violates the EAN rule :-

(A) Potassium ferrocyanide
(B) Potassium ferricyanide
(C) Tetra carbonyl Nickel
(D) Cobalt (III) hexamine chloride

2. If EAN of a central metal ion 𝐗 𝟐 in a complex is 34. and atomic number of X is 28. The number of
monodentet ligands present in complex are:-
(A) 3
(B) 4
(C) 6
(D) 2

3. The EAN of cobalt in the complex ion [𝐂𝐨(𝐞𝐧)𝟐 𝐂𝐥𝟐 ] is :-

(A) 27
(B) 36
(C) 33
(D) 35

4. Among the following complexes which can act as oxidising agent.

(A) [Mn(CO) ]
(B) [Mn(CO) ]
(C) [Mn(CO) ]–
(D) [V(CO) ]

5. Which of the following statement is correct regarding the compound "[(𝐂𝐎)𝟑 𝐅𝐞(𝐂𝐎)𝟑 𝐅𝐞(𝐂𝐎)𝟑 ]".
(A) The d – (bridging) is greater than d – (terminal)
(B) The bond order of bridging C – O bond is greater than that of terminal C – O bond
(C) The E.A.N. value of each Fe-atom is 35
(D) The oxidation state of Fe in this complex is (–1)

6. Effective atomic number of 𝐂𝐨(𝐂𝐎)𝟒 is 35, hence it is less stable. It attains stability by
(A) Oxidation of Co
(B) Reduction of Co
(C) Dimerization
(D) Both (B) & (C)

7. The EAN of metal atoms in 𝐅𝐞(𝐂𝐎)𝟐 (𝐍𝐎)𝟐 and 𝐂𝐨𝟐 (𝐂𝐎)𝟖 respectively are
(A) 34, 35
(B) 34, 36
(C) 36, 36
(D) 36, 35

[19]
Coordination Compounds

8. Match the complexes in column-I with the EAN of central atom in column-II:
Column-I Column-II
(A) [𝐅𝐞(𝐂𝐎)𝟒 ]𝟐 (P) 34
(B) [𝐂𝐨(𝐍𝐇𝟑 )𝟓 𝐂𝐥]𝐂𝐥𝟐 (Q) 35
(C) 𝐊 𝟐 [𝐍𝐢(𝐂𝐍)𝟒 ] (R) 36
(D) [𝐂𝐮(𝐍𝐇𝟑 )𝟒 ]𝟐 (S) 37
(A) A-(P), B-(R), C-(P), D-(S)

(B) A-(R), B-(R), C-(P), D-(Q)

(C) A-(P), B-(S), C-(R), D-(Q)

(D) A-(R), B-(S), C-(P), D-(Q)

Comprehension (9 to 10)
Ligands are neutral or ionic species capable of donating at least one electron pair to central metal. Hence
ligands can be of different denticities.
9. [𝐌𝐧(𝐂𝐎)𝟓 ] can attain more stability by :
(A) Oxidation of itself
(B) Reduction of itself
(C) Dimerization
(D) Both (B) and (C)

10. Which of the following complexes follow Sidgwick EAN rule ?

(A) [Fe(η − C H ) ]
(B) K[PtCl (η − C H )]
(C) [V(CO) ]
(D) [Mn(CO) ]

11. Sidwick EAN rule says that complex compound has the tendency to achieve the EAN of 36, 54 and 86 for
first, second and third transition series elements.
Which of the following complex is following sidwick EAN rule.
(A) [Ag(S O ) ] (when only 'S' atom is the donor atom)
(B) [Cd(CN) ]
(C) [Pt(en) ]
(D) [Mo(σ– C H )Br(NH ) ]

12. Which of the following complex is following sidwick EAN rule.

(A) [Ni(CO) ]
(B) K [Ni(CN) ]
(C) K [Hgl ]
(D) [Ag(NH ) ]Cl

[20]
Coordination Compounds

13. Which of the following do not act an oxidizing agent ?

(A) Mn(CO)
(B) Fe(CO)
(C) Mn (CO)
(D) Fe (CO)

14. Determine the effective atomic number of the metal atom in 𝐊 𝟑 [𝐂𝐫(𝐂𝟐 𝐎𝟒 )𝟑 ]

15. Determine the effective atomic number of the metal atom in 𝐊 𝟒 [𝐅𝐞(𝐂𝐍)𝟔 ]

16. Find the EAN value of central atom of [𝐅𝐞(𝛑– 𝐂𝟒 𝐇𝟒 )(𝐂𝐎)𝟑 ]

[21]
Coordination Compounds

Answer Key

Question 1 2 3 4 5 6 7 8 9 10
Answer B B B D A D C B D A
Question 11 12 13 14 15 16
Answer A A,C B,C,D 33 36 36

[22]
Coordination Compounds

ALLEN - INDIRANAGAR
Coordination Compounds DPP-05

1. The IUPAC name for [𝐂𝐨(𝐍𝐇𝟑 )𝟔 ] [𝐂𝐫(𝐂𝐍)𝟔 ] is :-

(A) Hexaamminecobalt(III) hexacyanochromate(III)
(B) Hexacyanochromium cobalt hexaammine(VI)
(C) Hexaammine cobalt(III) hexacyanochromium(VI)
(D) Hexacyanochromium(III) hexaammine cobalt(III)

2. The IUPAC name for [𝐂𝐨(𝐍𝐂𝐒)(𝐍𝐇𝟑 )𝟓 ]𝐂𝐥𝟐 is :-

(A) Pentaammine(thiocyanato-N)cobalt(III) chloride
(B) Pentaammine(thiocyanato-S)cobalt(III) chloride
(C) Pentaammine(isothiocyanato-N,S)cobalt(III) chloride
(D) Pentaammine(mercapto-N)cobalt(III) chloride

3. The IUPAC name of 𝐅𝐞(𝐂𝐎)𝟓 is

(A) Pentacarbonyl ferrate(0)
(B) Pentacarbonyl ferrate(III)
(C) Pentacarbonyliron(0)
(D) Pentacarbonyliron(II)

4. 𝐊 𝟑 [𝐅𝐞(𝐂𝐍)𝟔 ] is :-
(a) Potassium hexacynoferrate(II) (b) Potassium hexacynoferrate(III)
(c) Potassium ferricyanide (d) Hexacynoferrate(III) potassium
Correct answer is :-
(A) Only (a) and (b)
(B) Only (b) and (c)
(C) Only (a) and (c)
(D) Only (b) and (d)

5. Give the IUPAC name of the complex compound [𝐂𝐨(𝐍𝐇𝟑 )𝟒 (𝐇𝟐 𝐎)𝐁𝐫](𝐍𝐎𝟑 )𝟐 .
(A) BromoaquatetraamineCobalt(III) nitrate
(B) BromoaquatetraaminoCobalt(III) nitrate
(C) BromoaquatetraammineCobaltate(III) nitrate
(D) TetraammineaquabromoCobalt(III) nitrate

6. The number of ions formed, when bis(ethane-1,2-diamine)copper(II) sulphate is dissolved in water will
be
(A) 1
(B) 2
(C) 3
(D) 4

[26]
Coordination Compounds

7. The formula for the compound tris (ethane-1, 2-diamine)cobalt(III) sulphate is

(A) [Co(en) ]SO
(B) [Co(SO) (en) ]
(C) [Co(en) ](SO )
(D) [Co(en) ] (SO )

8. The compound 𝐍𝐚𝟐 [𝐅𝐞(𝐂𝐍)𝟓 𝐍𝐎 ] is called

(A) Sodium pentocyanonitrosoniumferrate(II)
(B) Sodium nitroprusside
(C) Sodium nitrosoferrocyanide
(D) A & B both

9. The IUPAC name of the Wilkinson's catalyst [𝐑𝐡𝐂𝐥(𝐏𝐏𝐡𝟑 )𝟑 ] is

(A) Chloridotris(triphenylphosphine)rhodium(I)
(B) Chloridotris(triphenylphosphine)rhodium(IV)
(C) Chloridotris(triphenylphosphine)rhodium(0)
(D) Chloridotris(triphenylphosphine)rhodium(VI)

10. The correct IUPAC name of the complex [𝐅𝐞(𝛑– 𝐂𝟓 𝐇𝟓 )𝟐 ] is

(A) Cyclopentadienyliron(II)
(B) Bis(η -cyclopentadienyl)iron(II)
(C) Dicyclopentadienylferrate(II)
(D) Ferrocene

11. Ziegler-Natta catalyst is ?

(A) Pt / PtO
(B) Al(C2H5)3 + TiCl4
(C) K[PtCl3(η – C2H4)]
(D) K[PtCl3(η – C2H4)]

12. Name the following compound according to IUPAC system

(A) Octammine-μ-chloro-μ-nitrodicobalt(II) sulphate

(B) Octaammine-μ-chloro-μ-nitrodicobalt(III) sulphate
(C) Octaammine-μ-nitro-μ-chlorodicobalt(III) sulphate
(D) None of the above

[27]
Coordination Compounds

Table for Question 13 to 15

Complex Oxidation state of central metal Ligand (s) present
atom or ion
(1) Ferrocene (P) 0 (i) C H
(2) Potassium ferrocynide (Q) +1 (ii) NO
(3) Sodium nitroprusside (R) +2 (iii) CN
(4) Zeise's salt (S) +3 (iv) Cl

13. Which of the following matching is INCORRECT : -

(A) (1),(R),(i)
(B) (2), (R), (iii)
(C) (3), (R), (ii) and (iii)
(D) (4), (S), (iv)

14. Select INCORRECT combination for complex given : -

(A) Complex having platinum = R, (iv)
(B) Neutral / uncharged complex = R, (i)
(C) Complex which have η – bonded ligand = R, (i)
(D) Sandwich complex = R, (i)

15. Which of the following complex having 𝛑-acid ligand (s) : -

(A) 1,2,3,4
(B) 1, 2, 3
(C) 1, 2
(D) 1, 4

[28]
Coordination Compounds

Answer Key

Question 1 2 3 4 5 6 7 8 9 10
Answer A A C B D B D D A B
Question 11 12 13 14 15
Answer B B D C A

[29]
Coordination Compounds

ALLEN - INDIRANAGAR
Coordination Compounds DPP-06

1. The type of isomerism present in pentaamminenitrochromium(III) chloride is :

(A) Coordination
(B) linkage
(C) hydrate
(D) Coordination position

2. Which of the following complex shows ionization isomerism

(A) [Cr(NH ) ]Cl
(B) [Cr(en) ]Cl
(C) [Cr(en) ]Cl
(D) [CoBr(NH ) ]SO

3. Find the name of the hydrate isomer of 𝐂𝐫𝐂𝐥𝟑 . 𝟔𝐇𝟐 𝐎, which is having lowest electrical conductivity
excluding zero value of conductivity.
(A) Hexaaquachromium(III)chloride
(B) Tetraaquadichloridochromium(III)chloride dihydrate
(C) Pentaaquachloridochromium(III)chloride monohydrate
(D) Triaquatrichloridochromium(III)chloride trihydrate

4. In coordination compounds, the hydrate isomers differ :-

(A) In the number of water molecules of hydration only
(B) In the number of water molecules only present as ligands
(C) Both in (A) and (B)
(D) In their coordination number of the metal atom

5. The two compounds sulphatopenta-amminecobalt(III) bromide and penta-amminebromo

cobalt(III) sulphate represent :
(A) Linkage isomerism
(B) Ionisation isomerism
(C) Co-ordination isomerism
(D) Hydrate isomerism

6. The compound [𝐂𝐫(𝐇𝟐 𝐎)𝟔 ]𝐂𝐥𝟑 𝐚𝐧𝐝 [𝐂𝐫(𝐇𝟐 𝐎)𝟒 𝐂𝐥𝟐 ]𝐂𝐥. 𝟐𝐇𝟐 𝐎 respresent
(A) Linkage isomerism
(B) Hydrate isomerism
(C) Ligand isomerism
(D) Ionisation isomerism

[32]
Coordination Compounds

7. Which of the following is considered to be an anticancer species ?

(A)

(B)

(C)

(D)

8. How many geometrical isomers are possible for the square-planar complex
[𝐏𝐭(𝐍𝐎𝟐 )(𝐩𝐲)(𝐍𝐇𝟑 )(𝐍𝐇𝟐 𝐎𝐇)]𝐍𝐎𝟐
(A) 4
(B) 5
(C) 8
(D) 3
9. Tetrahedral complexes generally do not exhibit geometrical isomerism because :
(A) They have plane of symmetry.
(B) They have centre of symmetry.
(C) All positions about central atom are adjacent with respect to each other.
(D) All position about central atom are at 180° with respect to central atom.

10. Which of the following tetrahedral complex has two stereoisomers ? [M = central atom, a, b, c, d =
monodentate ligands]
(A) [Ma B ]
(B) [Ma bc]
(C) [Mab c]
(D) [Mabcd]

11. A co-ordination compound [𝐌𝐚𝐛𝐜𝐝 ] has total two stereoisomers. The expected geometry of this complex
is : [M = central atom, a, b, c, d = monodentate ligands]
(A) Square planar
(B) octahedral
(C) Tetrahedral
(D) trigonal bipyramidal

[33]
Coordination Compounds

12. Select the correct statement for the following given complex :
O
O C
K B
O 2
(A) It show geometrical isomerism
(B) It has centre of symmetry
(C) All bond angles are identical
(D) It has no plane of symmetry

13. Which of the following complex is resolvable into d or l - forms ?

(A) [Zn(CN) ]
(B) [Ni(CO) ]
(C) [Be(PhCOCHCOCH ) ]
(D) [Zn(en) ]

14. Select which Square planar complex (es) can show optical isomerism : -
(A) [Pt(bn) ]
(B) [Pt(en) ]
(C) [PtCl (NH ) ]
(D) [Pt(gly) ]

15. Write all the geometrical isomers of [𝐏𝐭(𝐍𝐇𝟑 )(𝐁𝐫)(𝐂𝐥)(𝐩𝐲)] and how many of these will exhibit optical
isomers ?

16. Total number of geometrical isomers for the complex [𝐑𝐡𝐂𝐥(𝐂𝐎)(𝐏𝐏𝐡𝟑 )(𝐍𝐇𝟑 )] is.

Answer Key

Question 1 2 3 4 5 6 7 8 9 10
Answer B D B C B B C D C D
Question 11 12 13 14 15 16
Answer C D C A,D 0 3

[34]
Coordination Compounds

ALLEN - INDIRANAGAR
Coordination Compounds DPP-07

1. Theoretically the Number of geometrical isomers expected for octahedral complex [Mabcdef] is:-
(A) Zero
(B) 30
(C) 15
(D) 9

2. Which of the following complex produce precipitates with 𝐀𝐠𝐍𝐎𝟑 and exist in two geometrical isomeric
form
(A) PtCl . 4NH
(B) PtCl . 3NH
(C) PtCl . 4NH
(D) PtCl . 2NH

3. The pair of molecules that exhibit geometrical isomerism are

(A) [Cr(NH ) Cl ] and [Co(NH ) Cl ]
(B) [Cr (NH ) Cl] and [Co(NH ) Cl]
(C) [Cr(NH ) ] and [Co(NH ) ]
(D) All of the above show geometric isomerism

4. Which of the following statements is/are false

(A) In [PtCl (NH ) ] complex ion, the cis-form is optically active, while trans-form is optically inactive
(B) In [Fe(C O ) ] , geometrical isomerism does not exist, while optical isomerism exists
(C) [Mabcd]± square planar complexes exhibit both optical as well as geometrical isomerism
(D) In [Mabcd] ± tetrahedral complexes, optical isomerism cannot be observed

5. Identify the pair of complex which are stereoisomer of each other -

(A)
and

(B)

(C)
&

(D) All of the above

[38]
Coordination Compounds

6. Find complex which have maximum number of stereoisomers -

(A) [Ma b ]
(B) [Ma b c]
(C) [Ma b c ]
(D) [M(AA)a b ]

7. Which of the following ions are optically active ?

(A) I only
(B) II only
(C) II and III
(D) IV only

8. Which of the following is not optically active :-

(A) [Co(en) ]
(B) [Cr(ox) ]
(C) cis − [CoCl (en) ]
(D) trans − [CoCl (en) ]

9. How many optically active isomers are there for above complex mentioned in Question no (1) ?
(A) 2
(B) 3
(C) 4
(D) 6

10. Which of the following octahedral complex is optically active ?

[M = Central atom, (a, b, c, d = monodentate ligands), CD, AB = unsymmetrical bidentate ligand]

A
c
c B
A A
M
(A) M (B)
d B
B B
c A

c a
A A A a
(C) M (D) M
B B B a
d a

[39]
Coordination Compounds

11. Select the complex which has centre of symmetry : [M = central atom, AB = unsymmetrical bidentate
ligand, (a, b, c, d = monodentate ligands)]

B
A c
(A) M
B d
A

b
a A
(B) M
c B
d
c
A A
(C) M
B B
d
c
A B
(D) M
B A
c

12. The no of geometrical isomers for the complex [𝐌𝐂𝐥𝟐 (𝐋)𝟐 ] {where M = central atom,
𝐋 = 𝐍𝐇𝟐 — 𝐂𝐇𝟐 𝐂𝐎𝐎– } are :
(A) 2
(B) 4
(C) 5
(D) 6

13. How many geometrical isomers are optically inactive in complex mentioned in previous question ?
(A) 2
(B) 3
(C) 4
(D) 5

14. Which of the following compound(s) show(s) optical isomerism.

(A) [Pt(bn) ]
(B) [CrCl (en) ]
(C) [Co(en) ] [CoF ]
(D) [Zn(gly) ]

[40]
Coordination Compounds

15. Which of the following will have two stereoisomeric forms?

(A) [Cr(Cl ) (NH ) ]
(B) K [Fe(C O ) ]
(C) [CoCl (en) ]
(D) [CoBrCl(Ox) ]

16. Which of the following statement(s) is/are INCORRECT

(A) In [CoBrCl(en) ] geometrical isomerism exists, while optical isomerism does not exist
(B) Potassium aquadicyanidosuperoxidoperoxidochromate(III) is IUPAC name for K [Cr(CN) O (O )(H O)]
(C) here are 3 geometrical isomers and 15 stereoisomers possible for [Pt(NO )(NH )(NH OH)(py)] and
[PtBrC𝑙I(NO )(NH )(py)] respectively
(D) cis and trans forms are not diastereomers of each other

17. Which of the following is CORRECT about

Tetraamminedithiocyanato-Scobalt(III) tris(oxalato)cobaltate(III)
(A) formula of the complex is [Co(SCN) (NH ) ][Co(ox) ]
(B) It is a chelating complex and show linkage isomerism.
(C) It shows optical isomerism.
(D) It shows geometrical isomerism.

18. Find the maximum number of atoms lying in one plane for [𝐂𝐫(𝐂𝐍)𝟔 ]𝟑

19. Find out the total number of geometrical isomers of [𝐂𝐨(𝐇𝟐 𝐎)𝟑 𝐂𝐥𝟑 ].

20. Find the number of optically active isomers for [𝐏𝐝(𝐞𝐧)𝟐 (𝐍𝐇𝟑 )(𝐇𝟐 𝐎)]𝟒 cation.

Answer Key

Question 1 2 3 4 5 6 7 8 9 10
Answer C C A B C C C D C B
Question 11 12 13 14 15 16 17 18 19 20
Answer D C A A,B,C,D A,B A,B,C,D B,C,D 9 2 2

[41]
Coordination Compounds

ALLEN - INDIRANAGAR
Coordination Compounds DPP-8

1. What is the hybridisation of Fe in [𝐅𝐞(𝐂𝐎)𝟒 ]–𝟐

(A) d sp
(B) sp d
(C) sp d
(D) sp

2. Identify tetrahedral species which has maximum magnetic moment value :

(A) [CuCl ]
(B) [CoCl ]
(C) [FeCl ]
(D) [AlCl ]–

3. In the co-ordination compound 𝐍𝐚𝟒 [𝐅𝐞(𝐂𝐍)𝟓 𝐍𝐎𝐒] oxidation state of Fe is -

(A) +1
(B) +2
(C) +3
(D) +4

4. Which one of the following complex is an outer orbital complex -

(A) [Ni(H O) ]
(B) [Fe(H O) NO]SO
(C) [Fe(NH ) ]
(D) All of these

5. Which of the following is diamagnetic and 𝐬𝐩𝟑 hybridised -

(A) [NiCl ]
(B) [Ni(CN) ]
(C) [Ni(CN) ]
(D) [NiCl (PPh ) ]

6. [𝐂𝐫(𝐇𝟐 𝐎)𝟔 ]𝐂𝐥𝟑 (atomic number of Cr = 24) has a magnetic moment of 3.87 B.M. The CORRECT distribution
of 3d electrons in the chromium present in the complex is:
(A) 3d , 3d , 3d
(B) 3d , 3d , 3d
(C) 3d( ) , 3d , 3d
(D) 3d , 3d( ) , 3d

7. [𝐍𝐢(𝐂𝐎)𝟒 ] and [𝐍𝐢(𝐂𝐍)𝟒 ]𝟐 do not differ in

(A) magnetic moment
(B) oxidation number of Ni
(C) geometry
(D) EAN

[46]
Coordination Compounds

8. A complex of certain metal has the magnetic moment of 4.91 BM whereas another complex of the
same metal with same oxidation state has zero magnetic moment. The metal ion could be
(A) Co
(B) Mn
(C) Fe
(D) Fe

9. Out of [𝐅𝐞(𝐂𝐍)𝟔 ]𝟒 , [𝐍𝐢(𝐂𝐍)𝟒 ]–𝟐 and [𝐍𝐢(𝐂𝐎)𝟒 ]

(A) All have identical geometry.
(B) All are paramagnetic.
(C) All are diamagnetic.
(D) [Fe(CN) ]– is diamagnetic but [Ni(CN) ]– and [(Ni(CO) ] are paramagnetic

10. Which of the following compound is paramagnetic –

(A) Tetracyanonickelate(II) ion
(B) Tetraamminezinc(II) ion
(C) Hexaamine chromium(III) ion
(D) Diammine silver(I) ion

Answer Key

Question 1 2 3 4 5 6 7 8 9 10
Answer D C B D B A A C C C

[47]
Coordination Compounds

ALLEN - INDIRANAGAR
Coordination Compounds DPP-09

1. The number of unpaired electrons calculated in [𝐂𝐨(𝐍𝐇𝟑 )𝟔 ]𝟑 and [𝐂𝐨𝐅𝟔 ]𝟑 are :

(A) 4 and 4
(B) 0 and 2
(C) 2 and 4
(D) 0 and 4

2. According to C.F.T., ligands are treated as -

(A) Point charges
(B) Lewis acids
(C) Proton donor
(D) All of the above

3. In an octahedral crystal field, the 𝐭 𝟐𝐠 orbitals are

(A) Raised in energy by 0.4 Δ
(B) Lowered in energy by 0.4 Δ
(C) Raised in energy by 0.6 Δ
(D) Lowered in energy by 0.6 Δ

4. The complex [𝐅𝐞(𝐍𝐇𝟑 )𝟔 ]𝟐 is :

(A) Low spin
(B) High spin
(C) Diamagnetic
(D) both (A) and (C)

5. [𝐍𝐢𝐅𝟔 ]𝟐 is :
(A) Paramagnetic
(B) high spin
(C) Diamagnetic
(D) tetrahedral

6. [𝐌(𝐂𝟐 𝐎𝟒 )𝟑 ]𝐱 is diamagnetic when 𝐌 𝐧 ion is :

(A) Co
(B) Co
(C) Ni
(D) Fe

[50]
Coordination Compounds

7. Select appropriate ligand for given complex

+x
 III 
Co  ....... 6  ; 𝛍 = 0 BM
 
(A) C O
(B) en
(C) H O
(D) F –

8. Tetrahedral crystal field splitting energy ∆𝐭 is roughly how many times of octahedral crystal field splitting
energy ∆𝐎 ?
(A) 1/2
(B) 4/9
(C) 9/4
(D) 2

9. The value of crystal field stabilisation energy for a tetrahedral complex having 𝐝𝟓 configuration of central
metal ion is :
(A) – 0.6 ∆
(B) – 1.2 ∆
(C) – 0.4 ∆
(D) Zero

10. In crystal field theory for complex [𝐍𝐢𝐂𝐥𝟒 ]𝟐 , the lobes of how many d–orbitals of 𝐍𝐢 𝟐
coincide with
direction of the ligands ?
(A) zero
(B) Two
(C) Four
(D) One

11. What CFSE of a tetrahedral complex with 𝐝𝟐 configuration of central atom ?

(A) – 0.6 ∆t
(B) – 1.2 ∆t
(C) – 0.8 ∆t
(D) 0

12. How many unpaired electrons are there in 𝐝𝟕 tetrahedral complex ?

(A) 3
(B) 1
(C) 2
(D) 4

[51]
Coordination Compounds

13. Correct splitting energy diagram for square planar complex [𝐏𝐭𝐂𝐥𝟒 ]𝟐 is
d

dxy
(A)

d d

dxy
(B)
d

d d

dxz dyz dzx

(C)

d d

d d

(D)

dxy dyz dzx

14. How many unpaired electrons are there in square planar complex of 𝐂𝐨 𝟐
in weak field ligands ?
(A) 1
(B) 2
(C) 3
(D) 4

15. The number of unpaired electron in [𝐀𝐮𝐂𝐥𝟒 ]– is :

(A) 0
(B) 1
(C) 2
(D) 4

16. [𝐏𝐝𝐂𝐥𝟒 ]𝟐 is :
(A) Tetrahedral, 2 unpaired e– s.
(B) Square planar, paramagnetic
(C) Square planar, diamagnetic
(D) Tetra hedral, diamagnetic

[52]
Coordination Compounds

17. Nickel(Z = 28) combines with a uninegative monodentate ligand to form a diamagnetic complex
[𝐍𝐢𝐋𝟒 ]𝟐 . The hybridisation involved and the number of unpaired electrons present in the complex are
respectively :
(A) sp , zero
(B) sp , two
(C) dsp , one
(D) dsp , zero

18. Match List–I (Complex ions) with List–II (Number of Unpaired Electrons) and select the correct answer
using the codes given below the lists :-
List –I List II
(Complex ions) (Number of
Unpaired Electrons)
A. [𝐂𝐫𝐅𝟔 ]𝟒 i. One
B. [𝐌𝐧𝐅𝟔 ]𝟒 ii. Two
C. [𝐂𝐫(𝐂𝐍)𝟔 ]𝟒 iii. Three
D. [𝐌𝐧(𝐂𝐍)𝟔 ]𝟒 iv. Four
v. Five
(A) A-iv; B-i; C-ii; D-v
(B) A-ii; B-v; C-iii; D-i
(C) A-iv; B-v; C-ii; D-i
(D) A-ii; B-i; C-iii; D-v

19. If crystal field stablization energy of [𝐌𝐋𝟔 ] 𝐧

𝐢𝐬 – 𝟎. 𝟖 𝚫𝐎 .
Find minimum number of electrons in 𝐭 𝟐𝐠 orbitals of metal ion ?

Answer Key

Question 1 2 3 4 5 6 7 8 9 10
Answer D A B B C A C B D A
Question 11 12 13 14 15 16 17 18 19
Answer B A B A A C D C 2

[53]
Coordination Compounds

ALLEN - INDIRANAGAR
Coordination Compounds DPP-10

1. Crystal field stabilisation energy of a complex is affected by :

(A) Ligand strength
(B) Oxidation Number of central atom
(C) Coordination number
(D) All of these

2. ∆𝐎 is maximum for which of the following given complex?

(A) [Co(H O) F ]
(B) [Co(NH ) ]
(C) [Co(H O) ]
(D) [Co(NH ) ]

3. Select the correct general order of comparison :

(A) ∆ > ∆ > ∆
(B) ∆ > ∆ > ∆
(C) ∆ > ∆ > ∆
(D) ∆ > ∆ > ∆

4. CFSE in 𝐝𝟑 , octahedral is :
(A) – 1.2 ∆
(B) – 0.8 ∆
(C) +0.6 ∆
(D) – 2.4 ∆

5. If ∆𝟎 is crystal field spiliting energy and P is mean pairing energy per pair then stabilizing energy of
complex [𝐅𝐞𝐅𝟔 ]𝟒 is -
(A) –2.4 ∆ + 3P
(B) –2.0 ∆ + 3P
(C) –1.6 ∆ + P
(D) –0.4 ∆ + P

6. Calculate the crystal field stabilisation energy (CFSE) for (If pairing energy is ignored)
(A) d5 low spin octahedral
(B) d5 high spin octahedral
(C) d4 high spin octahedral
(D) d6 low spin octahedral

7. Which of the following complex is coloured and diamagnetic -

(A) MnO
(B) [Ni(H O) ]
(C) [CrCl ]
(D) CrO

[57]
Coordination Compounds

8. An ion 𝐌 𝟐 , forms the complexes [𝐌(𝐇𝟐 𝐎)𝟔 ]𝟐 , [𝐌(𝐞𝐧)𝟑 ]𝟐 and [𝐌𝐁𝐫𝟔 ]𝟒 , match the complex with the
appropriate colour.
(A) Green, blue and red
(B) Blue, red and green
(C) Green, red and blue
(D) Red, blue and green

9. If 𝛌𝐚𝐛𝐬𝐨𝐫𝐛𝐞𝐝 for d-d transition is in order [𝐓𝐢(𝐗)𝟔 ]𝟑 > [𝐓𝐢(𝐘)𝟔 ]𝟑 > [𝐓𝐢(𝐙)𝟔 ]𝟑 .
Select correct order of strength of ligands (X, Y, Z are monodentate ligand)-
(A) Z > Y > X
(B) X > Y > Z
(C) Z > X > Y
(D) Not predictable

10. The wave length of light absorbed is highest in :

(A) [Co(NH ) Cl]
(B) [Co(NH ) H O]
(C) [Co(NH ) ]
(D) [Co(en) ]

11. If a transition – metal compound absorbs violet – indigo radiation in the visible region. Its colour would
be
(A) Green
(B) Yellow
(C) Orange
(D) Blue

12. Which of the following compound is not coloured ?

(A) Na [CuCl ]
(B) Na [CdCl ]
(C) K [Fe(CN) ]
(D) K [Fe(CN) ]

13. Given the following data about the absorption maxima of several complex ions, what is the order of △𝟎
for these ions.
Compound 𝛌𝐦𝐚𝐱
I. [𝐂𝐫𝐂𝐥𝟔 ]𝟑 758
II. [𝐂𝐫(𝐍𝐇𝟑 )𝟔 ]𝟑 465
III. [𝐂𝐫(𝐇𝟐 𝐎)𝟔 ]𝟑 694
(A) △ (I) < △ (II) < △ (III)
(B) △ (II) < △ (III) < △ (I)
(C) △ (I) < △ (III) < △ (II)
(D) △ (III) < △ (II) < △ (I)

[58]
Coordination Compounds

Matching list type 1 × 3Q. (Three list type Question)

The following column I, II, III represent the different type of observations based on CFT in complex
compounds.
Answer the questions that follow
Column-I - Crystal field stablization energy (CFSE) (neglecting PE in all cases)
Column-II - Electronic configuration
Column-III - Type of complex
Column – I Column – II Column – III
CFSE Electronic Type of Complex
(neglecting PE in Configuration
all cases)
(I) −𝟎. 𝟒 ∆𝟎 (i) 𝐭 𝟓𝟐𝐠 , 𝐞𝟎𝐠 (P) High spin & Paramagnetic

(II) −𝟐. 𝟎 ∆𝟎 (ii) 𝐭 𝟒𝟐𝐠 , 𝐞𝟎𝐠 (Q) Low spin & Paramagnetic

(III) −𝟐. 𝟒 ∆𝟎 (iii) 𝐭 𝟔𝟐𝐠 , 𝐞𝟎𝐠 (R) High spin & Diamagnetic

(IV) −𝟏. 𝟐 ∆𝟎 (iv) 𝐭 𝟒𝟐𝐠 , 𝐞𝟐𝐠 (S) Low spin & Diamagnetic

14. For sodium nitroprusside complex the only CORRECT combination is

(A) (III), (iv), (Q)
(B) (III), (iii), (S)
(C) (III), (iii), (R)
(D) (II), (iii), (Q)

15. For [𝐂𝐨(𝐇𝟐 𝐎)𝟑 𝐅𝟑 ] complex the only CORRECT combination is.
(A) (I), (iv), (Q)
(B) (II), (iv), (S)
(C) (III), (ii), (R)
(D) (I), (iv), (P)

16. For [𝐌𝐧(𝐂𝐍)𝟔 ]𝟒 complex the only CORRECT combination is.

(A) (IV), (i), (S)
(B) (II), (i), (R)
(C) (I), (i), (S)
(D) (II), (i), (Q)

17. Select the correct stability order for the following complexes.
(A) [Cu(trien)] + > [Cu(en) ] > [Cu(NH ) ]
(B) [Ir(H O) ] > [Rh(H O) ] > [Co(H O) ]
(C) [Cr(NH ) ] > [Cr(NH ) ] > [Cr(NH ) ]
(D) [Cu(trien)] > [Cu(en) ] > [Cu(NH ) ]

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Coordination Compounds

18. In which of the following complex(s) spin only magnetic moment is independent , from the nature of
ligand. (L = monodented ligand) -
(A) [NiL ]
(B) [NiL ]
(C) [FeL ]
(D) [CrL ]

19. Which of the following ion is/are diamagnetic and non planar ?
(A) [Ni(CN) ]
(B) MnO–
(C) [Cu(NH ) ]
(D) CrO

20. Among the following species the one which causes the highest CFSE, ∆𝐎 as a ligand is :-
(A) CN –
(B) NH
(C) CO
(D) F –

Answer Key

Question 1 2 3 4 5 6 7 8 9 10
Answer D B B A D B D B A A
Question 11 12 13 14 15 16 17 18 19 20
Answer B B C B D D A,B,C B,D B,D C

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