1. Which of the following statement is CORRECT? (CFSE = Crystal Field Splitting Energy)

a) Lower CFSE favours formation of low spin complex

b) Higher CFSE favours formation of high spin complex

c) A particular metal ion in a particular oxidation state can form either diamagnetic complexes only or paramagnetic complexes only.

d) \(t_{28}\) orbitals are three-fold degenerate while \(e_B\) orbitals are two-fold degenerate

2. An example of ambidentate ligand is

a) ammine

b) chloro

c) oxalato

d) thiocyanate

3. Which of the following is a complex compound?

a) \(\mathrm{KCl}, \mathrm{MgCl}_2, 6 \mathrm{H}_2 \mathrm{O}\)

b) \(\mathrm{K}_2 \mathrm{SO}_4 \cdot \mathrm{Al}_4\left(\mathrm{SO}_4\right)_3 \cdot 24 \mathrm{H}_2 \mathrm{O}\)

c) \(\left[\mathrm{Co}(\mathrm{ONO})\left(\mathrm{NH}_3\right)_5\right] \mathrm{SO}_4\)

d) \(\mathrm{VO}_2 \mathrm{Cl}_2\)

4. Ligands in a complex salt are

a) anions linked by coordinate bonds to a central metal atom or ion

b) cations linked by coordinate bonds to a central metal atom or ion

c) only molecules linked by coordinate bonds to a central metal atom or ion

d) ions or molecules linked by coordinate bonds to a central atom or ion

5. The coordination number of copper in cuprammonium sulphate is

a) 2

b) 3

c) 4

d) 6

6. In the complexes \(\left[\mathrm{Fe}(\mathrm{CN})_6\right]^{3-}\) and \(\left[\mathrm{Cr}\left(\mathrm{C}_2 \mathrm{O}_4\right)_3\right]^{3-}\) , the respective coordination number of iron and chromium are

a) 6 and 3

b) 3 and 3

c) 6 and 6

d) 3 and 6

7. IUPAC name of \(\mathrm{K}_4\left[\mathrm{Fe}(\mathrm{CN})_6\right]\) is

a) tetrapotassium ferrocyanide

b) potassium ferricyanide

c) potassium ferrocyanide

d) potassium hexacyanoferrate

8. IUPAC name of \(\mathrm{K}_3\left[\mathrm{Fe}(\mathrm{CN})_6\right]\) is

a) potassiumferrocyanide

b) potassiurnferricyanide

c) potassiurnhexacyanoferrate (II)

d) potassiurnhexacyanoferrate (III)

9. IUPAC name of \(\mathrm{K}_3\left[\mathrm{Al}\left(\mathrm{C}_2 \mathrm{O}_4\right)_3\right]\) is

a) potassiumalumino-oxalato

b) potassiumaluminium(III)trioxalate

c) potassiumtrioxalatoaluminate(III)

d) potassiumtrisoxalatoaluminate(III)

10. In the coordination compound, \(\mathrm{K}_4\left[\mathrm{Ni}(\mathrm{CN})_4\right]\), the oxidation state of nickel is

a) -1

b) 0

c) +1

d) +2

11. Among the following ions which one has the highest paramagnetism ?

a) \(\left[\mathrm{Cr}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{3+}\)

b) \(\left[\mathrm{Fe}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+}\)

c) \(\left[\mathrm{Cu}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+}\)

d) \(\left[\mathrm{Zn}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+}\)

12. Which one of the following is expected to be a paramagnetic complex ?

a) \(\left[\mathrm{Ni}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{3+}\)

b) \(\left[\mathrm{Ni}(\mathrm{CO})_4\right]\)

c) \(\left[\mathrm{Zn}\left(\mathrm{NH}_3\right)_4\right]^{2+}\)

d) \(\left[\mathrm{Sc}\left(\mathrm{H}_2 \mathrm{O}\right)\right]^{3+}\)

13. The compound which does NOT show paramagnetism is

a) \(\left[\mathrm{Cu}\left(\mathrm{NH}_3\right)_4\right] \mathrm{Cl}_2\)

b) \(\left[\mathrm{Ag}\left(\mathrm{NH}_3\right)_2\right] \mathrm{Cl}\)

c) \(\left[\mathrm{FeF}_6\right]^{3-}\)

d) \(\left[\mathrm{T}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{3+}\)

14. Ethylenediamine is an example of

a) monodentate ligand

b) bidentate ligand

c) tridentate ligand

d) polydentate ligand

15. The colour of hexaamminecobalt(III) chloride is

a) yellow orange

b) red

c) violet

d) green

16. A group of atoms can function as a ligand only when

a) it is a small molecule

b) it has an unshared electron pair

c) it is a negatively charged ion

d) it is a positively charged ion

17. Which of the following ligand is the most strong field ligand?

a) \(\mathrm{CO}\)

b) \(\mathrm{H}_2 \mathrm{O}\)

c) \(\mathrm{OH}^{-}\)

d) \(\mathrm{Ox}^{2-}\)

18. Among the following the most stable complex is

a) \(\left[\mathrm{Fe}\left(\mathrm{H}_2 \mathrm{O}\right)_4\right]^{3+}\)

b) \(\left[\mathrm{Fe}(\mathrm{CN})_6\right]^{3-}\)

c) \(\left[\mathrm{FeI}_6\right]^{3-}\)

d) \(\left[\mathrm{FeCl}_6\right]^{3-}\)

19. \(\mathrm{CN}\) - is a strong field ligand. This is due to the fact that

a) it is a pseudo halide

b) it is a strong base

c) it forms high spin complex with metal species

d) it carries negative charge.

20. The coordination number of a central metal in a complex is determined by

a) the number of ligands around a metal ion bonded by sigma and pi bonds

b) the number of ligands around a metal ion bonded by only pi-bonds

c) the number of ligands around a metal ion bonded by only sigma bonds

d) the number of only anionic ligands bonded to the metal ion

21. Which one of the following complexes is outer orbital complex?

a) \(\left[\mathrm{Co}\left(\mathrm{C}_2 \mathrm{O}_4\right)_3\right]^{3-}\)

b) \(\left[\mathrm{Mn}(\mathrm{CN})_6\right]^{3-}\)

c) \(\left[\mathrm{Fe}(\mathrm{CN})_6\right]^{3-}\)

d) \(\left[\mathrm{CoF}_6\right]^{3-}\)

22. The oxidation state of \(\mathrm{Cr}\) in \(\left[\mathrm{Cr}\left(\mathrm{NH}_3\right)_4 \mathrm{Cl}_2\right]^{+}\)is

a) +3

b) +2

c) +1

d) 0

23. Which one of the following is a tridentate ligand?

a) trien

b) oxalato ion

c) EDTA

d) dien

24. Which of the following represents a chelating ligand?

a) \(\mathrm{H}_2 \mathrm{O}\)

b) \(\mathrm{NH}_3\)

c) DMG

d) \(\mathrm{Cl}^{-}\)

25. An ambidentate ligand is one which ?

a) is linked to the metal atom at two points

b) has two donor atoms but only one of them has the capacity to form a coordinate bond

c) has two donor atoms but either of the two can form a co-ordinate bond

d) forms chelate rings

26. A ligand having unshared pair of electron can be

a) a group containing a lone pair of electrons

b) a neutral molecule

c) a negatively charge ion

d) all of the above

27. A monodentate ligand has _.

a) one co-ordination site

b) two co-ordination sites

c) any number of co-ordination sites

d) no capacity to co-ordinate

28. \(\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_5 \mathrm{NO}_2\right] \mathrm{SO}_4\) and \(\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_5 \mathrm{SO}_4\right] \mathrm{NO}_2\) exhibit isomerism.

a) co-ordination

b) linkage

c) ionization

d) optical

29. Which one of the following statements is INCORRECT?

a) Greater the stability constant of a complex ion, greater is its stability.

b) Greater the charge on the central metal ion, greater is the stability of the complex.

c) Greater is the basic character of the ligand, the greater is the stability of the complex.

d) Chelate complexes have low stability constants.

30. Which of the following is NOT optically active?

a) \(\left[\mathrm{Co}(\mathrm{en})_3\right]^{3+}\)

b) \(\left[\operatorname{Cr}(o x)_3\right]^{3-}\)

c)cis- \(\left[\mathrm{CoCl}_2(\mathrm{en})_2\right]^{+}\)

d) trans- \([\mathrm{CoCl} 12 (\mathrm {en})_2]^{+}\)

31. Which of the following statements is INCORRECT?

a) Co-ordination compounds and complexes are synonymous terms.

b) Complexes always give ions in the solution.

c) Complexes may give ions in the solution or may not give ions in the solution.

d) Complex ion does not dissociate into its component parts even in the solution.

32. In \(\mathrm{Ni}(\mathrm{CO})_4\), each carbonyl ligand donate electron pair(s) to \(\mathrm{Ni}\).

a) 1

b) 2

c) 3

d) 4

33. The value of \(x\) which appears in the complex \(\left[\mathrm{Ni}(\mathrm{CN})_4\right] \mathrm{x}\) is

a) +2

b) -2

c) 0

d) 4

34. What is the shape of \(\mathrm{Fe}(\mathrm{CO}) \mathrm{s}\) ?

a) Square pyramidal

b) Octahedral

c) Linear

d) Trigonal bipyramidal

35. The number of unpaired electrons in low spin octahedral complexes of \(\mathrm{Cr}^{2+}\left(\mathrm{d}^4\right)\) and \(\mathrm{Fe}^{3+}\left(\mathrm{d}^5\right)\) are respectively.

a) 0 and 1

b) 2 and 1

c) 0 and 2

d) 1 and 0

36. Coordination isomerism is caused by the interchange of ligands between the

a) cis and trans structure

b) complex cation and complex anion

c) inner sphere and outer sphere

d) low oxidation and higher oxidation states

37. The neutral ligand is

a) chloride

b) hydroxide

c) hydroxyl amine

d) hydrazinium

38. A strong ligand gives a complex which is generally called

a) high spin

b) high energy

c) low spin

d) stable

39. The complex ions \(\left[\mathrm{Co}\left(\mathrm{H}_2 \mathrm{O}\right)_5,\left(\mathrm{NO}_2\right)\right]^{2+}\) and \(\left[\mathrm{Co}\left(\mathrm{H}_2 \mathrm{O}\right)_5-(\mathrm{ONO})\right]^{2+}\) are called. [Mar 2013]

a) linkage isomers

b) ionization isomers

c) co-ordination isomers

d) geometrical isomers

40. Which of the following is a common donor atom in ligands?

a) Arsenic

b) Nitrogen

c) Oxygen

d) Both b) and c)

41. Which one of the following octahedral complexes.will NOT show geometrical isomerism ( \(a\) and \(b\) are monodentate ligands)?

a) \(\left[\mathrm{Ma}_5 \mathrm{~b}\right]\)

b) \(\left[\mathrm{Ma}_2 \mathrm{~b}_4\right]\)

c) \(\left[\mathrm{Ma}_3 \mathrm{~b}_3\right]\)

d) \(\left[\mathrm{Ma}_4 \mathrm{~b}_2\right]\)

42. According to Werner's theory

a) primary valency can be ionized

b) secondary valency can be ionized

c) primary and secondary valencies both cannot be ionized

d) only primary valency cannot be ionized

43. The oxidation number of cobalt in \(\mathrm{K}\left[\mathrm{Co}(\mathrm{CO})_4\right]\) is (NCERT)

a) +1

b) +3

c) -1

d) -3