NEET UG - IUPAC nomenclature isomerism bonding approaches crystal field ideas colour and magnetic properties and importance in qualitative analysis and biological systems Question Bank with Options

1. In the complex [Co(NH3)4(H2O)Cl]2+, what is the oxidation state of Cobalt?

A) +1

B) +2

C) +3

D) +4

2. Which of the following is a monodentate ligand?

A) EDTA

B) Acetylacetonate

C) Phosphate

D) Chloride

3. The magnetic moment of [Fe(CN)6]4- is 0 BM. This indicates that the complex is:

A) Paramagnetic with unpaired electrons

B) Diamagnetic with no unpaired electrons

C) Paramagnetic with paired electrons

D) Ferromagnetic

4. Which of the following is an example of a complex used in chemotherapy?

A) Cisplatin

B) Hemoglobin

C) Chlorophyll

D) Vitamin B12

5. The color of [Cu(H2O)6]2+ is blue. This is due to absorption of light in the orange-red region of the spectrum, causing a d-d transition of which electron?

A) 3d9 to 3d8

B) 3d10 to 3d9

C) 3d9 to 4s

D) 3d9 to 3d10

6. In a square planar complex with configuration d8 and strong field ligands, the complex is usually:

A) High spin and paramagnetic

B) Low spin and diamagnetic

C) High spin and diamagnetic

D) Low spin and paramagnetic

7. Which type of isomerism is exhibited by [Co(NH3)5(SCN)]Cl2 and [Co(NH3)5(NCS)]Cl2?

A) Ionization isomerism

B) Coordination isomerism

C) Linkage isomerism

D) Optical isomerism

8. Hydrate isomerism occurs when:

A) The solvent molecules are coordinated to the metal ion

B) Water molecules are present as counter ions and coordinated ligands

C) Water molecules are present only as counter ions

D) Water molecules are present only as coordinated ligands

9. What is the IUPAC name of [Ag(NH3)2]Cl?

A) Diamminesilver(I) chloride

B) Silver(I) diamine chloride

C) Ammonia silver chloride

D) Diamminesilver(II) chloride

10. The chelate effect is most pronounced for:

A) Monodentate ligands

B) Bidentate ligands

C) Polydentate ligands

D) Ambidentate ligands

11. A complex with a magnetic moment of approximately 5.92 BM indicates the presence of how many unpaired electrons?

A) 1

B) 3

C) 5

D) 7

12. Which of the following complexes is likely to be colorless?

A) [Ni(H2O)6]2+

B) [Cu(NH3)4]2+

C) [Zn(H2O)6]2+

D) [Fe(CN)6]3-

13. The crystal field stabilization energy (CFSE) for a d1 ion in an octahedral field is:

A) -0.4 Δo

B) +0.6 Δo

C) -0.6 Δo

D) +0.4 Δo

14. What is the coordination number of the central metal ion in [PtCl2(NH3)2]?

A) 2

B) 3

C) 4

D) 6

15. The complex [Co(en)2(NO2)2]+ can exist as isomers. The isomer where the two NO2 groups are adjacent is called:

A) Trans isomer

B) Cis isomer

C) Facial isomer

D) Meridional isomer

16. Which isomerism arises when a ligand can coordinate through two different atoms?

A) Geometrical isomerism

B) Optical isomerism

C) Linkage isomerism

D) Coordination isomerism

17. What is the IUPAC name of [Fe(CO)5]?

A) Pentacarbonyliron(0)

B) Iron pentacarbonyl

C) Carbonyliron(0)

D) Pentacarbonyliron(II)

18. Chlorophyll, a pigment in plants, contains which metal ion?

A) Iron

B) Magnesium

C) Copper

D) Zinc

19. The electronic configuration of a central metal ion in a complex is d4. In an octahedral field, if it is a low spin complex, how many unpaired electrons are there?

A) 0

B) 1

C) 2

D) 4

20. Which of the following is a strong field ligand?

A) I-

B) Cl-

C) CN-

D) H2O

21. The spectrochemical series ranks ligands based on their ability to:

A) Donate electrons

B) Accept electrons

C) Cause crystal field splitting

D) Form coordinate bonds

22. In a tetrahedral field, the d-orbitals split into two sets, eg and t2g. Which set is lower in energy?

A) eg

B) t2g

C) Both have equal energy

D) Depends on the ligand

23. Which of the following is an example of ionization isomerism?

A) [Co(NH3)5SO4]Br and [Co(NH3)5Br]SO4

B) [Co(en)2Cl2]Cl and [Co(en)2Cl]Cl2

C) [Cr(NH3)6][Co(CN)6] and [Co(NH3)6][Cr(CN)6]

D) [Ni(dmg)2] and [Ni(dmg)(dmgH)]

24. Linkage isomerism arises due to the presence of:

A) Ambidentate ligands

B) Bidentate ligands

C) Chiral ligands

D) Chelating ligands

25. What is the IUPAC name of Na2[CoCl4]?

A) Sodium tetrachlorocobaltate(II)

B) Sodium tetrachlorocobalt(II)

C) Disodium tetrachlorocobaltate(II)

D) Sodium cobalt(II) tetrachloride

26. The presence of unpaired electrons in a complex is responsible for its:

A) Diamagnetism

B) Paramagnetism

C) Ferromagnetism

D) Antiferromagnetism

27. Which of the following is NOT a property explained by Werner's theory?

A) Formation of coordination compounds

B) The existence of coordination number

C) The color of complexes

D) The magnetic properties of complexes

28. The color observed is complementary to the color of light absorbed. If a complex absorbs green light, it will appear:

A) Blue

B) Red

C) Violet

D) Yellow

29. High spin complexes are favored when:

A) Δo < P (pairing energy)

B) Δo > P (pairing energy)

C) Δo = P (pairing energy)

D) P is very large

30. A complex with a large Δo value will absorb light of:

A) Longer wavelength

B) Shorter wavelength

C) Higher frequency

D) Lower energy

31. In crystal field theory, what does Δo represent?

A) Crystal field stabilization energy

B) Ligand field stabilization energy

C) Splitting energy in octahedral complexes

D) Spin pairing energy

32. Which type of isomerism is shown by [Co(NH3)5Br]SO4?

A) Linkage isomerism

B) Ionization isomerism

C) Hydrate isomerism

D) Coordination isomerism

33. Coordination isomerism occurs when:

A) The counter ion and the complex ion exchange ligands

B) The cation and anion parts of different complexes exchange ligands

C) The central metal ions exchange ligands

D) Ligands themselves undergo rearrangement

34. What is the IUPAC name for [Cr(en)3]Cl3?

A) Tris(ethylenediamine)chromium(III) chloride

B) Tri(ethylenediamine)chromium(III) chloride

C) Chromium(III) tris(ethylenediamine) chloride

D) Hexa(ethylenediamine)chromium(III) chloride

35. Which of the following ions is responsible for oxygen transport in blood?

A) Mg2+

B) Fe2+

C) Cu+

D) Zn2+

36. The magnetic moment of a complex is related to the number of unpaired electrons by which equation?

A) μ = √n(n+2) BM

B) μ = n(n+2) BM

C) μ = √n BM

D) μ = n BM

37. Which phenomenon explains the color of transition metal complexes?

A) Photoelectric effect

B) Tyndall effect

C) d-d transitions

D) Raman scattering

38. A complex with d5 configuration in an octahedral field can be high spin or low spin depending on:

A) The metal ion

B) The ligand

C) Temperature

D) All of the above

39. The splitting energy in an octahedral field is denoted by:

A) Δt

B) Δo

C) Δq

D) Δs

40. Which of the following complexes exhibits optical isomerism?

A) [Co(NH3)4Cl2]+

B) [Co(en)3]3+

C) [Co(NH3)6]3+

D) [CoCl4]2-

41. In Werner's theory, primary valency corresponds to:

A) Coordination number

B) Oxidation state of the metal ion

C) Number of ligands

D) Charge of the complex

42. The ligand that donates two donor atoms to the central metal ion is called:

A) Monodentate ligand

B) Bidentate ligand

C) Polydentate ligand

D) Ambidentate ligand

43. What is the oxidation state of Cobalt in K3[Co(CN)6]?

A) +1

B) +2

C) +3

D) +4

44. Which metal ion is central to Vitamin B12?

A) Iron

B) Cobalt

C) Copper

D) Magnesium

45. The color of a coordination compound is due to:

A) d-d transitions

B) Charge transfer transitions

C) Ligand field transitions

D) Both a and b

46. According to Crystal Field Theory (CFT), the splitting of d-orbitals in an octahedral complex is into two sets of orbitals with energies t2g and eg. Which set has lower energy?

A) eg

B) t2g

C) Both have equal energy

D) Depends on the metal ion

47. Which of the following is a bidentate ligand?

A) H2O

B) NH3

C) en (ethylenediamine)

D) CN-

48. In the complex [PtCl2(NH3)2], what type of isomerism is exhibited?

A) Ionization isomerism

B) Coordination isomerism

C) Geometric isomerism

D) Optical isomerism

49. What is the IUPAC name of the complex [Co(NH3)6]Cl3?

A) Hexamminecobalt(III) chloride

B) Hexamminecobalt(II) chloride

C) Cobalt(III) hexammine chloride

D) Triamminecobalt(III) chloride

IUPAC nomenclature isomerism bonding approaches crystal field ideas colour and magnetic properties and importance in qualitative analysis and biological systems - Question Bank