Experimental Inorganic Chemistry MCQs

1. Which technique is most commonly used to determine metal ion oxidation states in complexes?

(A) UV-Vis spectroscopy

(B) Polarimetry

(C) NMR spectroscopy

(D) Mössbauer spectroscopy

2. Which reagent is typically used to precipitate sulfate ions in inorganic qualitative analysis?

(A) AgNO₃

(B) K₄[Fe(CN)₆]

(C) NH₄Cl

(D) BaCl₂

3. The color of transition metal complexes is mainly due to:

(A) Nuclear transitions

(B) d–d electronic transitions

(C) Vibrational transitions

(D) Ionic radii

4. Which flame test color is characteristic of sodium ions?

(A) Green

(B) Yellow

(C) Brick red

(D) Violet

5. A gravimetric analysis typically involves:

(A) Measuring pH changes

(B) Titration

(C) Measuring absorbance

(D) Weighing a solid precipitate

6. In complexometric titration, the most widely used titrant is:

(A) EDTA

(B) KMnO₄

(C) AgNO₃

(D) HCl

7. Which metal ion gives a deep blue complex with ammonia?

(A) Mg²⁺

(B) Fe³⁺

(C) Zn²⁺

(D) Cu²⁺

8. Which reagent is used for the detection of chloride ions?

(A) BaSO₄

(B) NH₃

(C) AgNO₃

(D) KMnO₄

9. A ligand that can form more than one coordinate bond with a metal ion is called:

(A) Monodentate

(B) Anionic ligand

(C) Bridging

(D) Polydentate

10. The term “coordination number” refers to:

(A) Number of ligands attached

(B) Number of electrons gained

(C) Number of orbitals hybridized

(D) Number of oxidation states

11. Which technique helps determine crystal field splitting (Δ) in complexes?

(A) Mass spectrometry

(B) IR spectroscopy

(C) Polarography

(D) UV-Vis spectroscopy

12. In qualitative analysis, H₂S precipitates which group of cations?

(A) Group II

(B) Group I

(C) Group IV

(D) Group V

13. The oxidation state of Mn in KMnO₄ is:

(A) +7

(B) +6

(C) +4

(D) +2

14. Aqua regia is a mixture of:

(A) HCl and H₃PO₄

(B) HCl and HNO₃

(C) H₂SO₄ and HNO₃

(D) HClO₄ and H₂SO₄

15. Which compound is used as a drying agent in inorganic laboratories?

(A) KNO₃

(B) CuSO₄

(C) NaCl

(D) CaCl₂

16. Which complex has square planar geometry?

(A) [PtCl₄]²⁻

(B) [Ni(CO)₄]

(C) [Fe(CN)₆]³⁻

(D) [Zn(NH₃)₄]²⁺

17. The brown ring test is used for detecting:

(A) Nitrate

(B) Chloride

(C) Sulfate

(D) Phosphate

18. The ligand NH₃ is:

(A) Bridging only

(B) Anionic

(C) Cationic

(D) Neutral

19. Which gas is released when carbonate reacts with acid?

(A) O₂

(B) CO₂

(C) SO₂

(D) NH₃

20. Which reagent is used to detect phosphate ions?

(A) Ammonium molybdate

(B) AgNO₃

(C) NaOH

(D) BaCl₂

21. The spin-only magnetic moment formula is:

(A) √n

(B) n²

(C) √n(n+2)

(D) n/2

22. A diamagnetic substance contains:

(A) Paramagnetic ions

(B) Only unpaired electrons

(C) Only paired electrons

(D) d⁰ configuration only

23. Flame test for potassium shows:

(A) Blue

(B) Violet

(C) Brick red

(D) Yellow

24. The oxidation number of Fe in Fe₂O₃ is:

(A) +3

(B) +2

(C) +1

(D) +4

25. The splitting pattern in octahedral complexes is into:

(A) e_g and t₂g

(B) e and t₂

(C) p and d

(D) s and p

26. Which titration uses KMnO₄ as a self-indicator?

(A) Precipitation titration

(B) Complexometric titration

(C) Redox titration

(D) Acid-base titration

27. A hydrate loses water on heating. This experiment is part of:

(A) Volumetry

(B) Conductometry

(C) Chromatography

(D) Gravimetry

28. The reagent Nessler’s solution is used to detect:

(A) Nitrite

(B) Iron

(C) Sulfide

(D) Ammonia

29. A chelating ligand forms:

(A) Single bond with metal

(B) π-back bonding only

(C) Ionic bonds only

(D) Multiple bonds (rings) with metal

30. The geometry of [Ni(CN)₄]²⁻ is:

(A) Tetrahedral

(B) Square planar

(C) Octahedral

(D) Trigonal planar

31. The precipitate AgCl dissolves in:

(A) Dilute HCl

(B) H₂SO₄

(C) NH₃ solution

(D) NaOH

32. The reagent used in the borax bead test is:

(A) Boric acid

(B) Sodium borate

(C) Sodium carbonate

(D) Borax

33. Fe²⁺ can be oxidized to Fe³⁺ using:

(A) HCl

(B) Zn metal

(C) H₂O₂

(D) NH₄OH

34. Which ion gives Prussian blue color with Fe³⁺?

(A) SCN⁻

(B) CN⁻

(C) [Fe(CN)₆]⁴⁻

(D) F⁻

35. A complex with coordination number 6 usually has:

(A) Octahedral geometry

(B) Linear geometry

(C) Square planar geometry

(D) Tetrahedral geometry

36. In anhydrous CuSO₄, the color is:

(A) Blue

(B) White

(C) Green

(D) Pink

37. The reagent used to detect Fe³⁺ ions is:

(A) KMnO₄

(B) K₂CrO₄

(C) NH₄Cl

(D) KSCN

38. The oxidation state of chromium in K₂Cr₂O₇ is:

(A) +3

(B) +4

(C) +6

(D) +2

39. Which method is best for separating ions based on solubility?

(A) Chromatography

(B) Precipitation

(C) Spectroscopy

(D) Electrolysis

40. The reagent used to detect sulfide ions is:

(A) Conc. HCl

(B) NaOH

(C) AgNO₃

(D) Lead acetate

41. Which gas is used in inert-atmosphere inorganic synthesis?

(A) Nitrogen

(B) Oxygen

(C) Chlorine

(D) Ozone

42. The crystal field splitting is larger in:

(A) Tetrahedral complexes

(B) Linear complexes

(C) Octahedral complexes

(D) Square planar only

43. A blue solution turns pale green when reduced. The metal ion most likely is:

(A) Cr⁶⁺

(B) Fe³⁺

(C) Cu²⁺

(D) Ni²⁺

44. Which ion gives a brick-red flame?

(A) Ca²⁺

(B) Ba²⁺

(C) Sr²⁺

(D) Li⁺

45. “Ligand field theory” is an extension of:

(A) VBT

(B) CFT

(C) Electron-pair theory

(D) MO theory

46. Metal carbonyl compounds typically show strong absorption in:

(A) Microwave region

(B) UV region

(C) IR region

(D) X-ray region

47. A hydrate of formula CuSO₄·5H₂O loses color on heating because:

(A) Cu²⁺ reduces

(B) Water is lost

(C) H₂SO₄ forms

(D) Complex dissociates

48. Ion-exchange resin experiments are mainly used to separate:

(A) Neutral molecules

(B) Charged ions

(C) Gases

(D) Non-metals

49. The oxidation state of Co in [Co(NH₃)₆]Cl₃ is:

(A) +1

(B) +2

(C) +4

(D) +3

50. The iodometric titration commonly uses:

(A) Methyl orange

(B) Starch indicator

(C) Phenolphthalein

(D) Ferroin