Coordination Compounds Mock Test – Class 12 Chemistry

1. A four-coordinate complex is found to be diamagnetic and to have all four ligands in one plane. The most suitable valence bond description is:

2. Three structures are proposed for an octahedral -type complex.
Structure P: The ligands are opposite, and the structure has a plane of symmetry.
Structure Q: The ligands are adjacent, and the chelate rings form one handed arrangement.
Structure R: The ligands are adjacent, and the chelate rings form the non-superimposable mirror image of Q.
The correct classification is:

3. In , the oxidation state and -electron configuration of cobalt are respectively:

4. Complex absorbs at , while complex absorbs at . Using , , and , the combined result is:

5. In valence bond theory, hybridisation of the central metal orbitals is mainly used to explain:

6. A mutation alters the ligand environment around the iron centre of haemoglobin without removing the iron atom. Why can oxygen binding still be affected?

7. Complex has one unpaired electron and complex has three unpaired electrons. The ratio of their spin-only magnetic moments, , is:

8. A coordination compound dissolves according to

For of the compound, the moles of complex ions, counter ions, and total dissolved ions are respectively:

9. The magnetic behaviour of follows the chain:

10. donation, back-bonding, and low-oxidation-state stabilisation in metal carbonyls are integrated by the statement:

11. The complete description of is:

12. A sample of contains how many moles of metal–nitrogen coordinate bonds, assuming each ligand is bidentate?

13. Paired and high-spin octahedral arrangements differ as follows:

14. Which spin-only result is expected for a diamagnetic coordination complex?

15. For the stepwise formation equilibrium

the constant measures:

16. Assertion: is paramagnetic even though cyanido is a strong-field ligand.
Reason: A paired ion still contains one unpaired electron after two inner orbitals are made vacant.

17. The orbital arrangement consistent with the standard valence bond description of is:

18. Two ligands in an octahedral entity are replaced by one ethane-1,2-diamine ligand, represented by , without changing the coordination number. The resulting formula and total number of ligand molecules are:

19. The composition , written without brackets, does not by itself show the number of ionisable chloride ions. The additional evidence that most directly resolves this uncertainty is:

20. Which set of properties is most consistent with a standard strong-field square-planar complex?

21. Consider the following statements about metal–carbonyl back-bonding.
Statement I: It involves filled metal orbitals.
Statement II: It populates antibonding orbitals of .
Statement III: It increases the internal carbon–oxygen bond order.
Statement IV: It contributes to strengthening of the metal–carbon bond.
The valid statements are:

22. A compound contains a cobalt(III) centre, five coordinated ligands, one coordinated ligand, and two chloride counter ions. Its correct name is:

23. An entity contains one bidentate ligand, one bidentate oxalato ligand, and two monodentate ligands. Its coordination number and total number of ligand particles are respectively:

24. A student assigns square-planar geometry and diamagnetism to , reasoning that every diamagnetic four-coordinate nickel compound must be square planar. The assignment should be evaluated as follows:

25. An octahedral complex , where is mononegative, has , , and a magnetic moment close to . The data support the interpretation:

26. For two complexes containing the same ligand and metals of similar size, the complex of is often more stable than the analogous complex of because:

27. Two coordination entities contain the same metal in the same oxidation state but have different ligands. They may still differ in geometry and magnetic behaviour because:

28. Complex is a diamagnetic four-coordinate nickel(II) complex that absorbs at a shorter wavelength. Complex is a paramagnetic four-coordinate nickel(II) complex with two unpaired electrons and absorbs at a longer wavelength. Which assignment is most consistent?

29. Consider the following statements about chelating ligands.
Statement I: Ethane-1,2-diamine can form a chelate ring.
Statement II: Oxalato can bind through two oxygen atoms and form a chelate ring.
Statement III: Every polydentate ligand must use all its possible donor atoms in every coordination entity.
The valid statements are:

30. For an octahedral ion, low spin gains more CFSE than high spin but forms two additional electron pairs. Low spin is therefore favoured when:

31. In an octahedral complex of the type , the facial form is obtained when:

32. A octahedral complex has and . Its expected configuration is:

33. Consider the following statements about metal carbonyls.
Statement I: is treated as a neutral ligand.
Statement II: Neutral homoleptic metal carbonyls commonly contain metals in oxidation state .
Statement III: Polynuclear carbonyls contain more than one metal atom.
Statement IV: Coordination of requires the ligand to become in oxidation-state calculations.
The valid statements are:

34. The dissolution of in water is best represented by:

35. Assertion: Adding a donor-atom label to an ambidentate ligand name does not change the ligand’s formal charge.
Reason: The label identifies the atom bonded to the metal, while the chemical composition and formal charge of the ligand remain the same.

36. Regarding cyanide extraction of silver, the valid statement is:

37. The ideal bond angle between two adjacent ligand directions in a regular tetrahedral complex is approximately:

38. The fundamental distinction between structural isomerism and stereoisomerism is that:

39. is named:

40. In one form of , the two coordinated chloride ligands occupy adjacent octahedral positions. In another form, they occupy opposite positions. These two forms are:

41. Which relation correctly connects crystal-field splitting energy, frequency, and absorbed wavelength?

42. Which properties are the same for and ?

43. Assertion: Ionisation isomers can give different precipitates with suitable reagents.
Reason: The identity of the ion released from outside the coordination sphere differs between the isomers.

44. Two compounds have the same overall composition, but a bromido ligand inside the coordination sphere of one compound is a bromide counter ion in the other. Before any stereochemical counting, the pair should be classified as:

45. The usual valence bond reasoning for a strong-field octahedral complex follows the sequence:

46. Solvate isomerism arises when:

47. Assertion: The correct name of uses tris(ethane-1,2-diamine) rather than triethane-1,2-diamine.
Reason: Bis-, tris-, and tetrakis- are preferred for complicated or polydentate ligand names.

48. For , the oxidation state of chromium, charge on the coordination entity, and coordination number are respectively:

49. Study the isomer classifications.

The inconsistent row is:

50. Multiplying the equilibria

and

gives which overall equilibrium and constant relation?