1.Which of the following is not a d-block element?
(a) Zn
(b) Sc
(c) Cu
(d) Pb
Answer: (d) Pb
Explanation: Lead (Pb) is a p-block element, whereas Zn, Sc, and Cu belong to the d-block.
2. Which transition metal has the highest melting point?
(a) Fe
(b) W
(c) Ti
(d) Zn
Answer: (b) W (Tungsten)
Explanation: Tungsten has the highest melting point (3422°C) among all transition metals due to strong metallic bonding.
3. The color of transition metal complexes is due to:
(a) d-d transitions
(b) s-p transitions
(c) charge transfer
(d) none of these
Answer: (a) d-d transitions
Explanation: The presence of unpaired d-electrons allows electronic transitions between d-orbitals, which absorbs light and gives color.
4. Which transition element exhibits the maximum oxidation states?
(a) Fe
(b) Mn
(c) Cr
(d) Ti
Answer: (b) Mn
Explanation: Manganese (Mn) shows oxidation states from +2 to +7 due to variable d-orbital occupancy.
7. Which of the following is an example of a chelating ligand?
(a) Cl⁻
(b) CN⁻
(c) EDTA
(d) NO₃⁻
Answer: (c) EDTA
Explanation: EDTA (Ethylenediaminetetraacetate) binds to a metal through multiple donor sites (hexadentate).
8. The geometry of [Fe(CN)₆]⁴⁻ is:
(a) Square planar
(b) Tetrahedral
(c) Octahedral
(d) Trigonal bipyramidal
Answer: (c) Octahedral
Explanation: The Fe²⁺ ion forms an octahedral complex with six CN⁻ ligands.
5. The most stable oxidation state of copper is:
(a) +1
(b) +2
(c) +3
(d) +4
Answer: (b) +2
Explanation: Cu²⁺ is more stable than Cu⁺ due to a higher hydration enthalpy.
6. The magnetic moment of a d⁵ system in a high-spin complex is:
(a) 1.73 BM
(b) 2.83 BM
(c) 3.87 BM
(d) 5.92 BM
Answer: (d) 5.92 BM
Explanation: Using μ = √n(n+2), for n = 5 unpaired electrons, μ = √5(5+2) = 5.92 BM.
9. Lanthanides exhibit which common oxidation state?
(a) +1
(b) +2
(c) +3
(d) +4
Answer: (c) +3
Explanation: +3 is the most stable oxidation state due to the removal of outermost electrons from 6s and 4f orbitals.
10. The actinide contraction is due to:
(a) Poor shielding of 5f electrons
(b) Poor shielding of 4f electrons
(c) Poor shielding of d electrons
(d) Increase in nuclear charge
Answer: (a) Poor shielding of 5f electrons
Explanation: The weak shielding effect of 5f orbitals leads to gradual contraction across actinides.
11. Which of the following transition metals is used in stainless steel?
(a) Mn
(b) Ni
(c) Cr
(d) Co
Answer: (c) Cr
Explanation: Chromium (Cr) increases stainless steel’s corrosion resistance.
12. Which metal is used as a catalyst in the Haber process for ammonia synthesis?
(a) Pt
(b) Fe
(c) Ni
(d) Pd
Answer: (b) Fe
Explanation: Iron (Fe) acts as a catalyst in the Haber process to synthesize ammonia (NH₃).
NEET MCQs on F and D Block Elements
13. The electronic configuration of Cu is:
(a) [Ar] 3d⁹ 4s²
(b) [Ar] 3d¹⁰ 4s¹
(c) [Ar] 3d⁸ 4s²
(d) [Ar] 3d⁷ 4s²
Answer: (b) [Ar] 3d¹⁰ 4s¹
Explanation: Cu prefers 3d¹⁰ 4s¹ due to higher stability of a fully filled d-orbital.
14. Which metal is most resistant to corrosion?
(a) Fe
(b) Cu
(c) Pt
(d) Ag
Answer: (c) Pt
Explanation: Platinum (Pt) has a highly stable electron configuration and resists oxidation.
15. Which lanthanide is used in cigarette lighter flints?
(a) Ce
(b) Nd
(c) Eu
(d) Sm
Answer: (a) Ce
Explanation: Cerium (Ce) forms pyrophoric alloys used in lighter flints.
16. Which of the following is used in nuclear reactors?
(a) U
(b) Ce
(c) Sm
(d) Eu
Answer: (a) U
Explanation: Uranium (U) is used as fuel in nuclear reactors due to its fissionable properties.
17. Which of the following transition metals forms an amalgam with mercury?
(a) Fe
(b) Zn
(c) Ni
(d) Co
Answer: (b) Zn
Explanation: Zinc (Zn) readily forms an amalgam (alloy with mercury).
18. The most common oxidation state of actinides is:
(a) +2
(b) +3
(c) +4
(d) Variable
Answer: (d) Variable
Explanation: Actinides show variable oxidation states like +3, +4, +5, and +6 due to 5f-electron involvement.
19. Which of the following elements has an abnormal electronic configuration?
(a) Fe
(b) Zn
(c) Cr
(d) Mn
Answer: (c) Cr
Explanation: Chromium (Cr) has an exceptional electronic configuration [Ar] 3d⁵ 4s¹ due to extra stability of half-filled d-orbitals.
20. The ionization enthalpy of transition elements is:
(a) High
(b) Low
(c) Intermediate
(d) Unpredictable
Answer: (c) Intermediate
Explanation: Transition elements have intermediate ionization energy due to strong nuclear attraction and screening effects.
21. Which metal does not react with acids to release hydrogen gas?
(a) Fe
(b) Cu
(c) Zn
(d) Cr
Answer: (b) Cu
Explanation: Copper (Cu) is less reactive and does not react with non-oxidizing acids like HCl.
22. The most electropositive transition element is:
(a) Sc
(b) Zn
(c) Fe
(d) Ti
Answer: (a) Sc
Explanation: Scandium (Sc) has low ionization enthalpy and behaves as an electropositive metal.
23. Which of the following metal ions is colorless?
(a) Fe²⁺
(b) Cu²⁺
(c) Zn²⁺
(d) Cr³⁺
Answer: (c) Zn²⁺
Explanation: Zn²⁺ has a completely filled 3d¹⁰ orbital, so it does not exhibit d-d transitions and appears colorless.
24. The paramagnetic nature of transition metal ions is due to:
(a) Paired electrons
(b) Unpaired electrons
(c) Fully filled orbitals
(d) None of these
Answer: (b) Unpaired electrons
Explanation: Unpaired d-electrons create a magnetic moment, making transition metal ions paramagnetic.
25. The most common oxidation state of lanthanides is:
(a) +1
(b) +2
(c) +3
(d) +4
Answer: (c) +3
Explanation: Lanthanides typically show a +3 oxidation state due to their electronic configuration.
26. Which of the following is used in self-cleaning ovens?
(a) CeO₂
(b) Eu₂O₃
(c) La₂O₃
(d) ThO₂
Answer: (a) CeO₂
Explanation: Cerium(IV) oxide (CeO₂) is a strong oxidizing agent, making it useful in self-cleaning ovens.
27. Which actinide is used as a fuel in nuclear reactors?
(a) Ce
(b) U
(c) Eu
(d) Nd
Answer: (b) U
Explanation: Uranium (U) is widely used as a nuclear fuel due to its radioactive properties.
28. The actinide series starts from:
(a) Th
(b) Ac
(c) U
(d) Pu
Answer: (b) Ac
Explanation: The actinide series begins from Actinium (Ac) and includes elements from 89 to 103.
29. The shape of [Ni(CN)₄]²⁻ complex is:
(a) Tetrahedral
(b) Square planar
(c) Octahedral
(d) Trigonal bipyramidal
Answer: (b) Square planar
Explanation: Ni²⁺ with CN⁻ ligands undergoes sp²d hybridization, forming a square planar complex.
30. Which of the following is an inner transition metal?
(a) Fe
(b) Cu
(c) Ce
(d) Zn
Answer: (c) Ce
Explanation: Cerium (Ce) belongs to the lanthanide series, which is part of inner transition metals.
31. Which transition metal is used as a catalyst in the Ostwald process for nitric acid production?
(a) Pt
(b) Fe
(c) Ni
(d) Cu
Answer: (a) Pt
Explanation: Platinum (Pt) catalyzes oxidation of ammonia to nitric oxide in the Ostwald process.
32. Vanadium pentoxide (V₂O₅) is used in:
(a) Haber’s process
(b) Contact process
(c) Ostwald process
(d) Dow’s process
Answer: (b) Contact process
Explanation: V₂O₅ catalyzes SO₂ oxidation to SO₃ in the Contact Process for sulfuric acid production.
33. Brass is an alloy of:
(a) Cu and Zn
(b) Cu and Sn
(c) Fe and Cr
(d) Fe and Ni
Answer: (a) Cu and Zn
Explanation: Brass is a Cu-Zn alloy with enhanced malleability.
34. Stainless steel contains:
(a) Fe, C, and Zn
(b) Fe, Cr, and Ni
(c) Fe, Cu, and Zn
(d) Fe, Sn, and Ni
Answer: (b) Fe, Cr, and Ni
Explanation: Chromium (Cr) gives corrosion resistance to stainless steel.
35. The blue color of CuSO₄ solution is due to:
(a) Cu²⁺ ions
(b) Cu⁺ ions
(c) SO₄²⁻ ions
(d) Water molecules
Answer: (a) Cu²⁺ ions
Explanation: Cu²⁺ absorbs light and undergoes d-d transitions, giving a blue color.
36. Which transition element is used in blood sugar detection strips?
(a) Fe
(b) Mn
(c) Cr
(d) Zn
Answer: (c) Cr
Explanation: Chromium-based compounds are used in glucose detection tests.
37. The strongest oxidizing agent among transition metals is:
(a) Cu²⁺
(b) MnO₄⁻
(c) Cr³⁺
(d) Fe³⁺
Answer: (b) MnO₄⁻
Explanation: MnO₄⁻ (permanganate ion) has a high reduction potential and is a strong oxidizing agent.
38. The main impurity removed in the extraction of iron is:
(a) SiO₂
(b) CuO
(c) MnO₂
(d) PbO
Answer: (a) SiO₂
Explanation: Silica (SiO₂) is removed as slag in the iron extraction process using limestone.
39. Which of the following transition metals does not show variable oxidation states?
(a) Fe
(b) Zn
(c) Mn
(d) Cr
Answer: (b) Zn
Explanation: Zinc (Zn) always shows a +2 oxidation state because it has a fully filled 3d¹⁰ configuration.
40. The electronic configuration of Fe²⁺ is:
(a) [Ar] 3d⁶
(b) [Ar] 3d⁵ 4s¹
(c) [Ar] 3d⁷
(d) [Ar] 3d⁴
Answer: (a) [Ar] 3d⁶
Explanation: Fe (Z = 26) has [Ar] 3d⁶ 4s². Removing two electrons from 4s gives Fe²⁺ = [Ar] 3d⁶.
41. Which of the following is used as a catalyst in hydrogenation reactions?
(a) Cu
(b) Zn
(c) Ni
(d) Fe
Answer: (c) Ni
Explanation: Nickel (Ni) is a commonly used catalyst for hydrogenation of vegetable oils into fats.
42. The catalyst used in the decomposition of H₂O₂ is:
(a) Fe
(b) Pt
(c) MnO₂
(d) Cu
Answer: (c) MnO₂
Explanation: Manganese dioxide (MnO₂) catalyzes the decomposition of hydrogen peroxide (H₂O₂) into O₂ and H₂O.
43. The lanthanide contraction is responsible for:
(a) Decrease in atomic size
(b) Increase in atomic size
(c) Increase in metallic character
(d) Increase in basicity
Answer: (a) Decrease in atomic size
Explanation: Poor shielding of 4f electrons leads to a gradual decrease in atomic and ionic sizes across lanthanides.
44. The most commonly used radioactive element in smoke detectors is:
(a) U
(b) Pu
(c) Am
(d) Th
Answer: (c) Am (Americium)
Explanation: Americium-241 (Am-241) is used in smoke detectors as it emits alpha particles that ionize air.
45. Which of the following actinides is used in nuclear power generation?
(a) Thorium
(b) Neptunium
(c) Curium
(d) Berkelium
Answer: (a) Thorium
Explanation: Thorium (Th-232) is used in nuclear reactors as a fuel in the Thorium-Uranium fuel cycle.
46. The highest oxidation state shown by osmium (Os) is:
(a) +4
(b) +5
(c) +6
(d) +8
Answer: (d) +8
Explanation: Osmium (Os) can exhibit a maximum oxidation state of +8 (e.g., OsO₄, osmium tetroxide).
47. Which of the following shows a +7 oxidation state?
(a) Fe
(b) Mn
(c) Ni
(d) Cu
Answer: (b) Mn
Explanation: Manganese (Mn) exhibits a +7 oxidation state in KMnO₄ (potassium permanganate).
48. The alloy used in making aircraft components is:
(a) Duralumin
(b) Brass
(c) Bronze
(d) Steel
Answer: (a) Duralumin
Explanation: Duralumin (Al + Cu + Mg + Mn) is lightweight and strong, making it ideal for aircraft construction.
49. Nichrome wire is made of:
(a) Fe and Cr
(b) Ni and Cr
(c) Fe and Ni
(d) Cu and Zn
Answer: (b) Ni and Cr
Explanation: Nichrome (Ni + Cr) is used in heating elements due to its high resistance and oxidation resistance.
50. The oxidation state of Cr in [Cr(NH₃)₆]³⁺ is:
(a) +3
(b) +2
(c) 0
(d) +6
Answer: (a) +3
Explanation: The overall charge of the complex is +3, and NH₃ is a neutral ligand. So, Cr must be in the +3 oxidation state.
51. Which of the following complexes will have tetrahedral geometry?
(a) [Ni(CN)₄]²⁻
(b) [Cu(NH₃)₄]²⁺
(c) [CoCl₄]²⁻
(d) [Pt(NH₃)₂Cl₂]
Answer: (c) [CoCl₄]²⁻
Explanation: Weak field ligands (Cl⁻) favor tetrahedral geometry due to less crystal field splitting.
52. Which of the following has the highest density?
(a) Fe
(b) Cu
(c) Os
(d) Zn
Answer: (c) Os (Osmium)
Explanation: Osmium has the highest density (22.59 g/cm³), making it the densest naturally occurring metal.
53. Which transition metal is used in coinage?
(a) Ag
(b) Au
(c) Cu
(d) All of these
Answer: (d) All of these
Explanation: Copper (Cu), Silver (Ag), and Gold (Au) are used in coins due to their corrosion resistance and malleability.
54. Which of the following transition metals is used in artificial pacemakers?
(a) Pt
(b) Ti
(c) Cr
(d) Fe
Answer: (b) Ti
Explanation: Titanium (Ti) is biocompatible and corrosion-resistant, making it ideal for pacemakers.
55. The most abundant transition element in Earth’s crust is:
(a) Fe
(b) Ti
(c) Cu
(d) Zn
Answer: (b) Ti
Explanation: Titanium (Ti) is the most abundant transition metal in the Earth’s crust, found in minerals like rutile (TiO₂).
56. The melting point of transition metals generally:
(a) Increases across the series
(b) Decreases across the series
(c) Remains constant
(d) Shows no definite trend
Answer: (a) Increases across the series
Explanation: Due to strong metallic bonding, melting points generally increase across the transition series until mid-series and then decrease.