NCERT BOOK CLASS 12TH CHEMISTRY MCQ
Chapter 5 : Coordination Compounds
Important MCQs with Answers
1. What type of bond exists between the central metal atom and the ligand in coordination compounds?
a) Ionic
b) Covalent
c) Coordinate covalent
d) Hydrogen
Answer: c) Coordinate covalent
2. What is the oxidation state of Fe in [Fe(CN)₆]³⁻?
a) +2
b) +3
c) +4
d) +6
Answer: b) +3
3. Which of the following ligands is bidentate?
a) NH₃
b) EDTA
c) Oxalate (C₂O₄²⁻)
d) CO
Answer: c) Oxalate (C₂O₄²⁻)
4. What is the IUPAC name of the complex [Co(NH₃)₆]³⁺?
a) Hexaamminecobalt(III) ion
b) Tris(ammine)cobalt(III) ion
c) Hexaamminecobalt(II) ion
d) Cobalt hexaammine (III) ion
Answer: a) Hexaamminecobalt(III) ion
5. Which of the following is NOT a Werner’s complex?
a) [Co(NH₃)₆]Cl₃
b) K₃[Fe(CN)₆]
c) [Pt(NH₃)₂Cl₂]
d) FeSO₄·7H₂O
Answer: d) FeSO₄·7H₂O
6. What is the oxidation state of nickel in [Ni(CO)₄]?
a) 0
b) +1
c) +2
d) +4
Answer: a) 0
7. Which of the following ligands is anionic?
a) NH₃
b) H₂O
c) Cl⁻
d) CO
Answer: c) Cl⁻
8. What is the shape of the complex ion [Ag(NH₃)₂]⁺?
a) Linear
b) Square planar
c) Tetrahedral
d) Octahedral
Answer: a) Linear
9. Which metal is present in hemoglobin?
a) Fe
b) Mg
c) Co
d) Zn
Answer: a) Fe
10. What is the oxidation state of Fe in [Fe(CN)₆]⁴⁻?
a) +2
b) +3
c) +4
d) +6
Answer: a) +2
11. Which of the following complexes is paramagnetic?
a) [Zn(NH₃)₄]²⁺
b) [Ni(CN)₄]²⁻
c) [CoF₆]³⁻
d) [Fe(CN)₆]⁴⁻
Answer: c) [CoF₆]³⁻
12. What is the region around a metal ion created by ligands called?
a) Crystal field
b) Ligand field
c) Valence field
d) Ionic field
Answer: a) Crystal field
13. What is the shape of [Ni(CN)₄]²⁻?
a) Tetrahedral
b) Square planar
c) Linear
d) Octahedral
Answer: b) Square planar
14. Which of the following is a strong-field ligand?
a) F⁻
b) Cl⁻
c) CN⁻
d) Br⁻
Answer: c) CN⁻
15. The color of the complex ion [Co(NH₃)₆]³⁺ is due to:
a) d-d transition
b) Charge transfer
c) Photon absorption
d) Electron excitation
Answer: a) d-d transition
16. What is the color of the complex ion [Cu(NH₃)₄]²⁺?
a) Blue
b) Green
c) Deep blue
d) Violet
Answer: c) Deep blue
17. Which of the following complexes can be explained by Werner’s theory?
a) [Co(NH₃)₆]Cl₃
b) [Ni(CO)₄]
c) K₄[Fe(CN)₆]
d) All of the above
Answer: d) All of the above
18. What is the oxidation state of Cr in [Cr(H₂O)₆]³⁺?
a) +2
b) +3
c) +4
d) +6
Answer: b) +3
19. Which of the following complexes is colorless?
a) [Fe(H₂O)₆]²⁺
b) [Cu(NH₃)₄]²⁺
c) [Zn(NH₃)₄]²⁺
d) [Co(H₂O)₆]²⁺
Answer: c) [Zn(NH₃)₄]²⁺
20. What does ‘en’ represent in [Co(en)₃]³⁺?
a) Ethylenediamine
b) Ammonia
c) Cyanide
d) Carbonyl
Answer: a) Ethylenediamine
21. Which of the following complexes exhibits octahedral geometry?
a) [Ni(CO)₄]
b) [Co(NH₃)₆]³⁺
c) [Pt(NH₃)₂Cl₂]
d) [Ag(NH₃)₂]⁺
Answer: b) [Co(NH₃)₆]³⁺
22. Crystal field splitting energy (CFSE) depends on:
a) Nature of the metal ion
b) Nature of the ligand
c) Geometry of the complex
d) All of the above
Answer: d) All of the above
23. Between [Fe(CN)₆]⁴⁻ and [Fe(H₂O)₆]²⁺, which complex will be low-spin due to strong-field ligands?
a) [Fe(CN)₆]⁴⁻
b) [Fe(H₂O)₆]²⁺
c) Both
d) None
Answer: a) [Fe(CN)₆]⁴⁻
24. Which ligand is hexadentate?
a) EDTA
b) Oxalate
c) Ethylenediamine
d) Pyridine
Answer: a) EDTA
25. What is the shape and magnetic behavior of [NiCl₄]²⁻?
a) Tetrahedral, paramagnetic
b) Square planar, diamagnetic
c) Linear, paramagnetic
d) Octahedral, diamagnetic
Answer: a) Tetrahedral, paramagnetic
26. What is the IUPAC name of the complex ion [Co(NH₃)₅Cl]²⁺?
a) Pentaamminechloridocobalt(III) ion
b) Chloropentaamminecobalt(II) ion
c) Pentaamminechloridocobalt(II) ion
d) Chlorocobalt pentaammine (III) ion
Answer: a) Pentaamminechloridocobalt(III) ion
27. In which of the following complexes does d²sp³ hybridization occur?
a) [Fe(CN)₆]³⁻
b) [Ni(CN)₄]²⁻
c) [CoF₆]³⁻
d) [Cu(NH₃)₄]²⁺
Answer: a) [Fe(CN)₆]³⁻
28. Which metal is present in chlorophyll?
a) Fe
b) Mg
c) Zn
d) Co
Answer: b) Mg
29. What does ‘en’ represent in [Co(en)₂Cl₂]⁺?
a) Ethylenediamine
b) Ammonia
c) Cyanide
d) Carbonyl
Answer: a) Ethylenediamine
30. Which of the following complexes exhibits square planar geometry?
a) [Ni(CO)₄]
b) [Pt(NH₃)₂Cl₂]
c) [Co(NH₃)₆]³⁺
d) [Zn(NH₃)₄]²⁺
Answer: b) [Pt(NH₃)₂Cl₂]
31. What is the electronic configuration of Cr³⁺ ion in [Cr(NH₃)₆]³⁺ complex ion?
a) 3d³
b) 3d⁵
c) 3d⁶
d) 3d¹⁰
Answer: a) 3d³
32. Which of the following complexes will be diamagnetic?
a) [Fe(H₂O)₆]²⁺
b) [Cu(NH₃)₄]²⁺
c) [Ni(CN)₄]²⁻
d) [CoF₆]³⁻
Answer: c) [Ni(CN)₄]²⁻
33. Between [Co(NH₃)₆]³⁺ and [CoF₆]³⁻, which complex will be high spin?
a) [Co(NH₃)₆]³⁺
b) [CoF₆]³⁻
c) Both
d) None
Answer: b) [CoF₆]³⁻
34. Which of the following ligands is neutral?
a) NH₃
b) Cl⁻
c) CN⁻
d) OH⁻
Answer: a) NH₃
35. What is the color of [Fe(H₂O)₆]²⁺ complex ion?
a) Green
b) Blue
c) Pink
d) Yellow
Answer: a) Green
36. Which of the following complexes exhibits tetrahedral geometry?
a) [Ni(CN)₄]²⁻
b) [PtCl₄]²⁻
c) [Cu(NH₃)₄]²⁺
d) [Co(NH₃)₆]³⁺
Answer: c) [Cu(NH₃)₄]²⁺
37. What is the oxidation state of Co in [Co(CN)₆]³⁻ complex ion?
a) +2
b) +3
c) +4
d) +6
Answer: b) +3
38. Which of the following complexes will be colorless?
a) [Cu(H₂O)₆]²⁺
b) [Fe(CN)₆]⁴⁻
c) [Zn(NH₃)₄]²⁺
d) [Co(H₂O)₆]²⁺
Answer: c) [Zn(NH₃)₄]²⁺
39. Between [Fe(CN)₆]³⁻ and [FeF₆]³⁻, which complex will be low spin due to strong field ligands?
a) [Fe(CN)₆]³⁻
b) [FeF₆]³⁻
c) Both
d) None
Answer: a) [Fe(CN)₆]³⁻
40. Which of the following ligands is monodentate?
a) EDTA
b) Oxalate
c) Ethylenediamine
d) NH₃
Answer: d) NH₃
41. What is the hybridization of Cu²⁺ ion in [Cu(NH₃)₄]²⁺ complex ion?
a) sp³
b) dsp²
c) d²sp³
d) sp³d²
Answer: b) dsp²
42. Which of the following complexes will be paramagnetic?
a) [Zn(NH₃)₄]²⁺
b) [Ni(CN)₄]²⁻
c) [Co(NH₃)₆]³⁺
d) [Fe(CN)₆]⁴⁻
Answer: c) [Co(NH₃)₆]³⁺
43. What is the geometry of [Pt(NH₃)₂Cl₂] complex?
a) Tetrahedral
b) Square planar
c) Linear
d) Octahedral
Answer: b) Square planar
44. Which of the following complexes will be high spin?
a) [Fe(CN)₆]⁴⁻
b) [Co(NH₃)₆]³⁺
c) [Fe(H₂O)₆]²⁺
d) [Ni(CN)₄]²⁻
Answer: c) [Fe(H₂O)₆]²⁺
45. What does ‘en’ represent in [CoCl₂(en)₂]⁺?
a) Ethylenediamine
b) Ammonia
c) Cyanide
d) Carbonyl
Answer: a) Ethylenediamine
46. Which of the following complexes exhibits octahedral geometry?
a) [Ni(CO)₄]
b) [Co(NH₃)₆]³⁺
c) [Pt(NH₃)₂Cl₂]
d) [Ag(NH₃)₂]⁺
Answer: b) [Co(NH₃)₆]³⁺
47. Between [Fe(CN)₆]⁴⁻ and [Fe(H₂O)₆]²⁺, which complex will be low spin due to strong ligands?
a) [Fe(CN)₆]⁴⁻
b) [Fe(H₂O)₆]²⁺
c) Both
d) None
Answer: a) [Fe(CN)₆]⁴⁻
48. Which of the following ligands is hexadentate?
a) EDTA
b) Oxalate
c) Ethylenediamine
d) Pyridine
Answer: a) EDTA
49. What is the shape and magnetic behavior of [NiCl₄]²⁻ complex ion?
a) Tetrahedral, paramagnetic
b) Square planar, diamagnetic
c) Linear, paramagnetic
d) Octahedral, diamagnetic
Answer: a) Tetrahedral, paramagnetic
50. What is the IUPAC name of [Co(NH₃)₅Cl]²⁺ complex ion?
a) Pentaamminechloridocobalt(III) ion
b) Chloropentaamminecobalt(II) ion
c) Pentaamminechloridocobalt(II) ion
d) Chlorocobalt pentaammine (III) ion
Answer: a) Pentaamminechloridocobalt(III) ion
51. What is the bond formed between metal ion and ligand in coordination compounds called?
a) Ionic bond
b) Covalent bond
c) Coordinate bond
d) Hydrogen bond
Answer: c) Coordinate bond
52. What is the oxidation state of cobalt in [Co(NH₃)₅NO₂]Cl₂?
a) +1
b) +2
c) +3
d) +4
Answer: c) +3
53. Which of the following ligands is tridentate?
a) EDTA
b) Diethylenetriamine
c) Oxalate
d) Cyanide
Answer: b) Diethylenetriamine
54. What is the color of [Cr(H₂O)₆]³⁺ complex ion?
a) Blue
b) Green
c) Violet
d) Yellow
Answer: c) Violet
55. Which of the following complexes shows square planar geometry?
a) [Ni(CO)₄]
b) [Cu(NH₃)₄]²⁺
c) [PtCl₄]²⁻
d) [Co(NH₃)₆]³⁺
Answer: c) [PtCl₄]²⁻
56. Between [Fe(CN)₆]³⁻ and [FeF₆]³⁻, which complex will be paramagnetic?
a) Only [Fe(CN)₆]³⁻
b) Only [FeF₆]³⁻
c) Both
d) None
Answer: b) Only [FeF₆]³⁻
57. Which of the following complexes shows tetrahedral geometry?
a) [Ni(CN)₄]²⁻
b) [Cu(NH₃)₄]²⁺
c) [Pt(NH₃)₂Cl₂]
d) [Co(NH₃)₆]³⁺
Answer: b) [Cu(NH₃)₄]²⁺
58. What is the hybridization of cobalt in [Co(en)₃]³⁺?
a) sp³
b) dsp²
c) d²sp³
d) sp³d²
Answer: c) d²sp³
59. Which of the following ligands causes maximum field splitting?
a) F⁻
b) Cl⁻
c) CN⁻
d) Br⁻
Answer: c) CN⁻
60. What is the hybridization of silver in [Ag(NH₃)₂]⁺ complex ion?
a) sp
b) sp²
c) sp³
d) dsp²
Answer: a) sp
61. Which of the following complexes will be diamagnetic?
a) [Fe(H₂O)₆]²⁺
b) [Cu(NH₃)₄]²⁺
c) [Ni(CO)₄]
d) [CoF₆]³⁻
Answer: c) [Ni(CO)₄]
62. What is the hybridization of nickel in [Ni(CN)₄]²⁻?
a) sp³
b) dsp²
c) d²sp³
d) sp³d²
Answer: b) dsp²
63. Which of the following complexes is not octahedral?
a) [Co(NH₃)₆]³⁺
b) [Fe(CN)₆]³⁻
c) [Ni(CO)₄]
d) [Cr(H₂O)₆]³⁺
Answer: c) [Ni(CO)₄]
64. What is the oxidation state of iron in [Fe(CN)₆]⁴⁻?
a) +2
b) +3
c) +4
d) +6
Answer: a) +2
65. Which of the following complexes will be colorless?
a) [Cu(H₂O)₆]²⁺
b) [Fe(H₂O)₆]³⁺
c) [Zn(NH₃)₄]²⁺
d) [Co(H₂O)₆]²⁺
Answer: c) [Zn(NH₃)₄]²⁺
66. What is the IUPAC name of [Co(NH₃)₅Cl]Cl₂?
a) Pentaamminechloridocobalt(III) chloride
b) Chloropentaamminecobalt(II) chloride
c) Pentaamminechlorocobalt(II) chloride
d) Chlorocobalt pentaammine chloride
Answer: a) Pentaamminechloridocobalt(III) chloride
67. Which of the following complexes will be high spin?
a) [Fe(CN)₆]⁴⁻
b) [Co(NH₃)₆]³⁺
c) [Fe(H₂O)₆]²⁺
d) [Ni(CN)₄]²⁻
Answer: c) [Fe(H₂O)₆]²⁺
68. What is the color of [Cu(NH₃)₄]²⁺ complex ion?
a) Blue
b) Deep blue
c) Green
d) Yellow
Answer: b) Deep blue
69. Which of the following complexes can be explained by Werner’s theory?
a) [Co(NH₃)₆]Cl₃
b) K₄[Fe(CN)₆]
c) [Ni(CO)₄]
d) All of the above
Answer: d) All of the above
70. What is the oxidation state of chromium in [Cr(NH₃)₆]³⁺ complex ion?
a) +2
b) +3
c) +4
d) +6
Answer: b) +3
71. Which of the following ligands is anionic?
a) NH₃
b) H₂O
c) Cl⁻
d) CO
Answer: c) Cl⁻
72. What is the color of [Fe(H₂O)₆]²⁺ complex ion?
a) Green
b) Blue
c) Pink
d) Yellow
Answer: a) Green
73. Which of the following complexes will be paramagnetic?
a) [Zn(NH₃)₄]²⁺
b) [Ni(CN)₄]²⁻
c) [CoF₆]³⁻
d) [Fe(CN)₆]⁴⁻
Answer: c) [CoF₆]³⁻
74. What is the geometry of [Pt(NH₃)₂Cl₂] complex?
a) Tetrahedral
b) Square planar
c) Linear
d) Octahedral
Answer: b) Square planar
75. Which of the following complexes will be colorless?
a) [Cu(H₂O)₆]²⁺
b) [Fe(CN)₆]⁴⁻
c) [Zn(NH₃)₄]²⁺
d) [Co(H₂O)₆]²⁺
Answer: c) [Zn(NH₃)₄]²⁺