Boron And Aluminum MCQs [Chemistry]

By: Prof. Dr. Fazal Rehman | Last updated: May 23, 2025

1. : AICI₃ acts as a strong Lewis acid because it
(A) A covalent compound
(B) Electron-deficient
(C) Readily hydrolyzed
(D) An ionic compound

2. : Which of the mentioned has +3 oxidation state?
(A) In & Tl
(B) B & Al
(C) B & In
(D) Al & TI

3. : Which of the mentioned are oxide ores of Aluminum?
(A) Corundum
(B) Diaspore
(C) Bauxite
(D) All A, B, and C

4. : Which of the mentioned are sulphate ores of aluminum?
(A) Kaolin
(B) Cryolite
(C) Feldspar
(D) Alumite

5. : The formula of Bauxite is
(A) Al₂O₃
(B) Na₃AlF₆
(C) Al₂O₃·H₂O
(D) Al₂O₃·2H₂O

6. : The purification of Bauxite can be carried out by
(A) Serpek’s process
(B) Hall’s process
(C) Baeyer’s process
(D) None of A, B, and C

7. : In the purification of bauxite, the ore is fused with sodium carbonate in the ________ process.
(A) Baeyer’s process
(B) Hall’s process
(C) Serpeck’s process
(D) None of A, B, and C

8. : Aluminum is helpful and used for which of the following?
(A) Reducing agent
(B) Making alloys
(C) Making utensils & frames
(D) All A, B, and C

9. : Magnalium is alloy of aluminum and magnesium which is helpful and used in ______.
(A) Scientific apparatus
(B) Boat machinery
(C) Rail road cars
(D) Aircraft parts

10. : What is the formula of hexa borane?
(A) B₄H₁₀
(B) B₅H₉
(C) B₆H₁₀
(D) B₈H₁₂

11. : Which is an inflammable colorless gas with a sticky sweet odour and is extremely toxic?
(A) B₄H₁₀
(B) B₂H₆
(C) B₅H₉
(D) B₆H₁₀

12. : Diborane is helpful and used ___
(A) As reducing agent
(B) For welding torches
(C) For high energy fuel
(D) All A, B, and C

13. : What is the formula of Borax?
(A) Na₂B₄O₇·12H₂O
(B) Na₂B₄O₇·8H₂O
(C) Na₂B₄O₇·10H₂O
(D) Na₂B₄O₇·6H₂O

14. : What is the formula of Tetraboric acid?
(A) H₂B₄O₇
(B) HBO₂
(C) H₃BO₃
(D) H₆B₄O₂

15. : Boric acid is helpful and used in ____ .
(A) Tanning industry
(B) Medicine as an antiseptic
(C) Manufacture of pottery glaze
(D) All A, B, and C

16. : Borax exists in which form?
(A) Borax glass
(B) Octahedral borax
(C) Ordinary borax
(D) All A, B, and C

17. : What is the formula of borax glass?
(A) Na₂B₄O₇·10H₂O
(B) Na₂B₄O₇
(C) Na₂B₄O₇·5H₂O
(D) None of these

18. : Sodium tetraborate is helpful and used ______ .
(A) As alkaline buffer in dyeing & bleaching process
(B) In enameling and making glaze
(C) In manufacture of optical glass
(D) All A, B, and C

19. : AICI₃ is helpful and used in
(A) Borax bead test
(B) Manufacturing of petrol
(C) Preservation of food
(D) All A, B, and C

20. : Which of the mentioned reacts violently with water?
(A) AlH₃
(B) AlCl₃
(C) Al₂Cl₆
(D) LiAlH₄

21. : Alum is a _____.
(A) Double salt
(B) Acidic salt
(C) Basic salt
(D) Complex salt

22. : Boron and aluminum halides are electron-deficient compounds. In this respect, they act as
(A) Oxidizing agent
(B) Lewis base
(C) Lewis acid
(D) Reducing agent

23. : Which one of the following elements shows the most stable oxidation state of +1?
(A) Al
(B) Tl
(C) In
(D) Ga

24. : Boron exhibits diagonal relationship with which of the following?
(A) Mg
(B) Si
(C) Al
(D) Ge

25. : Alums are generally helpful and used in ______ .
(A) In dyeing and water proofing of fabric
(B) In arrest bleeding
(C) In water purification
(D) All A, B, and C

26. : Boron does not form B3+ ion because it has __________ .
(A) high electronegativity
(B) It has small size and high ionization energy
(C) high charge density (charge/radius ratio)
(D) None of these

27. : The aqueous solution of sodium silicate is ______.
(A) Acidic
(B) Amphoteric
(C) Basic
(D) Neutral

28. : AlCl3 fumes in air because of
(A) Hydration
(B) Dehydration
(C) Hydrolysis
(D) Oxidation

29. : Which of the mentioned statements about anhydrous aluminum chloride is true?
(A) It is not easily hydrolyzed
(B) It exists as AlCl3 molecules
(C) It sublimes at 100°C under vacuum
(D) None of these

30. : Which of the mentioned statements is not true for both B and Al?
(A) They burn in oxygen to give oxides at high temperature
(B) Their halides are Lewis acids
(C) They combine with nitrogen to form nitrides
(D) They react with HCl to form chlorides

31. : Amorphous boron on burning in air forms __ .
(A) Mixture of B2O3 and BN
(B) Only B2O3
(C) Only BN
(D) B(OH)3

32. : Which of the mentioned is expected not to exist?
(A) B5H11
(B) B5H10
(C) B6H10
(D) B5H8

33. : What is the formula of chrome yellow?
(A) PbCrO4
(B) K2CrO4
(C) K2Cr2O7
(D) None of these

34. : The accurate order of atomic radii of Group IIIA elements is
(A) B < Al < Ga - In
(B) B < Al - Ga < In
(C) B < Al < Ga < In
(D) B < Ga < Al - In

35. : In the aluminothermite process, aluminum acts as
(A) An oxidizing agent
(B) A flux
(C) A solder
(D) A reducing agent

36. : When borax is intensely heated, it gives __________ .
(A) B2O3
(B) NaBO2 + B2O3
(C) NaBO2
(D) Na2B4O7

37. : Which of the mentioned forms electron deficient compounds?
(A) Al
(B) B
(C) Both B & Al
(D) None of these

38. : Which of the mentioned elements are typical non-metals?
(A) B & Al
(B) Al & Si
(C) B & Si
(D) All A, B, and C

39. : The compound which does not act as Lewis acid is
(A) BF3
(B) BeCl2
(C) AlCl3
(D) SnCl4

40. : When orthoboric acid is heated intensely, it gives _________ .
(A) HBO2
(B) H2B3O7
(C) B2O3
(D) B

41. : Which of the mentioned statements is not true about potash alum?
(A) Its empirical formula is KAl(SO4)2
(B) Its aqueous solution is basic in nature
(C) It is helpful and used in dyeing industry
(D) On heating, it melts in its water of crystallization

42. : Which one of the following statements regarding BF3 is not true?
(A) It is a Lewis acid
(B) It is an electron-deficient compound
(C) It is an ionic compound
(D) It forms adducts

43. : All the members of group III A are metals excluding ___________.
(A) Ga
(B) Al
(C) B
(D) In

44. : What is the valence shell electronic configuration of group III A?
(A) ns1 p2
(B) ns2 p3
(C) ns2 p1
(D) ns2 p2

45. : Which of the mentioned element gives violet color to flame?
(A) Aluminum
(B) Indium
(C) Thallium
(D) Gallium

46. : The aluminium salt commonly helpful and used to stop bleeding is
(A) Aluminium sulphate
(B) Aluminium chloride
(C) Potash alum
(D) Aluminium fluoride

47. : Aluminum does not corrode as does iron, because _____ .
(A) Al does not react with O2
(B) A protective layer of Al2O3 forms on the metal surface
(C) Al is harder to oxidize than is Fe
(D) Fe gives cathode protection to Al

48. : Which of the mentioned statement is false?
(A) An alloy is a mixture of two or more metals
(B) An alloy is a mixture of two or more metal and non-metal elements that have metallic properties
(C) An alloy has a fixed composition
(D) An amalgam is an alloy containing Hg

49. : The role of the mineral cryolite, Na3AlF6, in the Hall process for aluminum production is
(A) In the molten state, it is a solvent for alumina, Al2O3
(B) It is a chemical reducing agent
(C) It forms a slag to remove impurities
(D) It is the source of aluminum (the ore)

50. : The Hall process involves the reduction of Al2O3 to aluminum by ______ .
(A) Carbon (coke)
(B) Carbon monoxide
(C) Electrolysis
(D) Molecular hydrogen

51. : Aluminum is an active metal, but does not corrode as iron does because
(A) Al does not react with O2
(B) A protective layer of Al2O3 forms on the metal surface
(C) Al is harder to oxidize than is Fe
(D) Aluminum has a high tensile strength

52. : Which of the mentioned is not a property of aluminum?
(A) An efficient electrical conductor
(B) Toxic to humans
(C) Is amphoteric
(D) A low density compared to other metals

53. : Aluminum hydroxide Al(OH)3 is ______ .
(A) An amphoteric hydroxide
(B) An acid
(C) A base
(D) An explosive hydroxide

54. : Which of the mentioned is not alum?
(A) KAl(SO4)2·12H2O
(B) NaAl(SO4)2·12H2O
(C) FeAl(SO4)2·12H2O
(D) NH4Fe(SO4)2·12H2O

55. : Duralumin is an alloy of
(A) Mg + Al + Cu + Mn
(B) Al + Mg + Mn
(C) Mg + Al + Cu
(D) Mg + Al

56. : Mangalium is an alloy of
(A) Mg + Al + Cu
(B) Mg + Al + Mn
(C) Al + Mg
(D) Mg + Al + Cu + Mn

57. : BCl3 is a planar molecule, because B atom is ________ hybridized.
(A) sp-hybridized
(B) sp³-hybridized
(C) sp²-hybridized
(D) sp³d-hybridized

58. : Which of the mentioned hydroxide is amphoteric?
(A) Al(OH)3
(B) B(OH)3
(C) Ga(OH)3
(D) In(OH)3

59. : Which is the chief ore of aluminum?
(A) Cryolite
(B) Kaolin
(C) Bauxite
(D) Carnalite

60. : What is the chemical formula of bauxite?
(A) Al2O3
(B) Al2Cl6
(C) Na3AlF6
(D) Al2O3·2H2O

61. : Boric acid is added to glass, because it _________ .
(A) Makes the glass opalescent
(B) Reduces the coefficient of expansion
(C) Makes the glass brittle
(D) Increase refractive index of the glass

62. : The true Lewis acid strength order is
63. : In B2H6 molecule
(A) There exists a direct B-B σ-bond
(B) All the atoms are in one plane
(C) All the B-H bonds are normal covalent bonds
(D) There exist two (three-center two-electron) bonds between the boron atoms.

64. : The nature of borax solution is
(A) Acidic
(B) Alkaline
(C) Neutral
(D) Amphoteric

65. : Which is the most abundant metal in earth’s crust?
(A) Fe
(B) Al
(C) Ti
(D) Ca

66. : Which is the element with maximum first ionization energy (or ionization potential)?
(A) B
(B) N
(C) O
(D) C

67. : Which metal burns in air at high temperature with the evolution of much heat?
(A) Cu
(B) Hg
(C) Pb
(D) Al

68. : Aluminum halide is
(A) White crystalline solid
(B) Hygroscopic
(C) Sublimes at 180°C
(D) All A, B, and C

69. : Which liberates H2 with NaOH?
(A) Zn
(B) Al
(C) B
(D) All

70. : Group IIIA of the periodic table consist of how many elements?
(A) 3
(B) 5
(C) 3
(D) 7

71. : Which of the mentioned is mineral of Al?
(A) Bauxite
(B) Feldspar
(C) Mica
(D) All A, B, and C