Class 12 रसायन विज्ञान Ch-8 d- एवं f-ब्लॉक के तत्व MCQs

नीचे दिए गए सभी Questions Bihar Board परीक्षा 2026 के लिए “Very Important Questions” (अत्यंत महत्वपूर्ण प्रश्न) हैं। इन सभी Class 12th के (Chemistry/रसायन विज्ञान) = रसायन विज्ञान भाग-1 (Hindi Medium) Book Chapter-8 d- एवं f-ब्लॉक के तत्व का Questions का Solve का  वीडियो Youtube और Website पर Upload किया गया है।

1. The oxidation state of Iron in Brown Ring complex $[Fe(H_{2}O)_{5}NO]SO_{4}$ is: [BSEB, 2018 A]
(A) +1
(B) +2
(C) +3
(D) 0

2. Which of the following ions is diamagnetic? [BSEB, 2025 A]
(A) $Cr^{2+}$
(B) $V^{2+}$
(C) $Sc^{3+}$
(D) $Ti^{3+}$

3. In which of the following elements, the 4f energy level is gradually filled? [BSEB, 2021 A]
(A) Lanthanoids
(B) Actinoids
(C) Transition metals
(D) Coinage metals

4. The best conductor of electricity among the following is:
(A) Iron
(B) Copper
(C) Gold
(D) Silver

5. Which of the following transition metals shows the maximum number of oxidation states? [BSEB, 2020 A]
(A) Mn
(B) Cr
(C) Fe
(D) V

6. Mercuric chloride reacts with ammonia gas to form a white precipitate. The formula of the precipitate is: [BSEB, 2018 A]
(A) $HgCl_{2} \cdot 2NH_{3}$
(B) $Hg(NH_{3})_{2}Cl_{2}$
(C) $Hg(NH_{2})Cl$
(D) $Hg(NH_{2})_{2}Cl$

7. Which of the following has zero dipole moment? [BSEB, 2025 A]
(A) $CH_{3}Cl$
(B) $CCl_{4}$
(C) $CH_{2}Cl_{2}$
(D) $CHCl_{3}$

8. Electronic configuration of Gadolinium (Z = 64) is: [BSEB, 2023 A]
(A) $[Xe] 4f^{7} 5d^{1} 6s^{2}$
(B) $[Xe] 4f^{8} 6s^{2}$
(C) $[Xe] 4f^{3} 5d^{5} 6s^{2}$
(D) None of these

9. Maximum oxidation state of Chromium is: [BSEB, 2024 A]
(A) +2
(B) +3
(C) +4
(D) +6

10. Which of the following elements of 3d-series does not show variable oxidation states? [BSEB, 2021 A]
(A) Fe
(B) Cu
(C) Ti
(D) Zn

11. Transition elements are:
(A) Metals
(B) Non-metals
(C) d-block elements
(D) Gases

12. The number of unpaired electrons in $Cu^{2+}$ (Z = 29) ion is: [BSEB, 2024 A]
(A) 0
(B) 1
(C) 2
(D) 3

13. Which of the following is called Coinage Metal? [BSEB, 2023 A]
(A) Fe, Co, and Ni
(B) Cu and Zn
(C) Cu, Ag, and Au
(D) Au and Pt

14. Actinides ki adhiktam (maximum) oxidation state hoti hai:
(A) +4
(B) +6
(C) +7
(D) +5

15. When NaCl solution is added to $Fe(OH)_{3}$ sol, then: [BSEB, 2018 A]
(A) $[Fe(OH)_{3}]Fe^{3+}$ is obtained
(B) $[Fe(OH)_{3}]Cl^{-}$ is obtained
(C) $[Fe(OH)_{3}]Na^{+}$ is obtained
(D) $Fe(OH)_{3}$ is precipitated

16. The general electronic configuration of Lanthanide elements is: [BSEB, 2025 A]
(A) $(n-2)f^{1-14} (n-1)s^{2} p^{6} d^{0,1} ns^{2}$
(B) $(n-2)f^{0-14} (n-1)d^{10} ns^{2}$
(C) $(n-2)f^{0-14} (n-1)d^{0,1} ns^{2}$
(D) $(n-2)d^{0,1} (n-1)f^{0-14} ns^{1}$

17. Oxidation state of Nickel in $[Ni(CO)_{4}]$ is: [BSEB, 2021 A]
(A) 0
(B) +1
(C) -1
(D) +4

18. Transition metals are generally paramagnetic because of:
(A) High melting and boiling points
(B) Presence of vacant d-orbitals
(C) Presence of unpaired electrons
(D) Malleability and ductility

19. Which of the following is a liquid metal?
(A) Li
(B) Ga
(C) Hg
(D) All of these

20. Which element in the first transition series shows the highest oxidation state? [BSEB, 2021 A]
(A) Ni
(B) Cr
(C) Fe
(D) Mn

21. Zinc (Zn) ko sankraman tatva (transition element) nahi maana jata kyunki:
(A) Ye s-block ka hai
(B) Iska d-orbital poorn (fully filled) hai
(C) Ye d-block mein nahi hai
(D) None of these

22. Which transition element has the smallest atomic radius?
(A) Sc
(B) Ni
(C) Cu
(D) Zn

23. Which of the following is not a member of 3d-transition series? [BSEB, 2017 A]
(A) Ti
(B) Cr
(C) Mg
(D) Fe

24. The magnetic moment ($\mu$) of an ion with 3 unpaired electrons is: [BSEB, 2021 A]
(A) 2.87 BM
(B) 3.87 BM
(C) 4.87 BM
(D) 5.87 BM

25. Main components of Brass are:
(A) Cu and Sn
(B) Cu and Al
(C) Cu and Zn
(D) Cu and Hg

26. Red lead is: [BSEB, 2016 C]
(A) $Pb_{3}O_{4}$
(B) $Pb_{2}O_{3}$
(C) $PbO$
(D) $PbO_{2}$

27. Which of the following metals has the highest density? [BSEB, 2019 A]
(A) Pd
(B) Pt
(C) Rh
(D) Hg

28. General electronic configuration of transition elements is: [BSEB, 2017 A, 2022 A]
(A) $(n-1)d^{1-10} ns^{1-2}$
(B) $(n-1)d^{5} ns^{2}$
(C) $(n-1)d^{1-5} ns^{0}$
(D) None of these

29. Lutetium (Lu) is: [BSEB, 2025 A]
(A) A transition element
(B) A Lanthanide
(C) An Actinide
(D) A p-block element

30. Main components of German Silver are:
(A) Cu, Zn, Ni
(B) Cu, Zn, Sn
(C) Ag, Cu, Au
(D) Fe, Cr, Ni

31. The color of $KMnO_{4}$ is due to: [BSEB, 2019 A]
(A) d-d transition
(B) Charge transfer spectra
(C) p-d transition
(D) None of these

32. $Fe^{2+}$ ion mein ayugmit (unpaired) electronon ki sankhya kitni hai? [BSEB, 2017 A]
(A) 4
(B) 5
(C) 6
(D) 3

33. Electronic configuration of $Cu^{2+}$ (Z = 29) is: [BSEB, 2023 A]
(A) $[Ar] 3d^{8} 4s^{1}$
(B) $[Ar] 3d^{7} 4s^{2}$
(C) $[Ar] 3d^{9}$
(D) $[Ar] 3d^{6} 4s^{2} 4p^{1}$

34. In the following pairs, the transition elements are:
(A) Na and Ca
(B) Mg and Al
(C) S and P
(D) Cu and Fe

35. Whose +2 oxidation state is most stable? [BSEB, 2018 A]
(A) Sn
(B) Ag
(C) Fe
(D) Pb

36. The number of unpaired electrons in $Lu^{3+}$ is:
(A) 0
(B) 1
(C) 2
(D) 3

37. Which of the following oxides is paramagnetic? [BSEB, 2025 A]
(A) $CO_{2}$
(B) $ClO_{2}$
(C) $SO_{2}$
(D) $SiO_{2}$

38. Which of the following ions is paramagnetic? [BSEB, 2024 A]
(A) $Sc^{3+}$
(B) $Cu^{+}$
(C) $Zn^{2+}$
(D) $Cu^{2+}$

39. Total number of known series of transition elements is:
(A) 2
(B) 3
(C) 4
(D) 5

40. Which of the following metals has the minimum boiling point?
(A) Na
(B) Cs
(C) Zn
(D) Hg

41. The noble gas found in abundance in the atmosphere is: [BSEB, 2025 A]
(A) He
(B) Ar
(C) Xe
(D) Rn

42. Which of the following is not a first transition series element? [BSEB, 2010 A, 2012 A, 2017 C]
(A) Iron (Fe)
(B) Chromium (Cr)
(C) Magnesium (Mg)
(D) Nickel (Ni)

43. Lanthanide contraction ka sambandh kiske sath hai?
(A) Paramanu trijya (Atomic radius)
(B) Oxidation avastha
(C) Magnetic moment
(D) Ionization potential

44. Shape of d-orbital is:
(A) Spherical
(B) Dumbbell
(C) Double Dumbbell
(D) None of these

45. Which of the following elements belongs to the actinide series? [BSEB, 2024 A]
(A) Gd
(B) Th
(C) La
(D) Sm

46. Which of the following is the most abundant transition metal in the Earth’s crust?
(A) Cu
(B) Al
(C) Fe
(D) Zn

47. Which of the following is an element of the second transition series? [BSEB, 2022 A]
(A) Fe
(B) Zr
(C) Pt
(D) Sc

48. Main components of Rolled Gold are:
(A) Cu and Al
(B) Cu and Sn
(C) Cu and Zn
(D) Cu and Cr

49. Which of the following is an alkaline earth metal? [BSEB, 2015 A]
(A) Carbon
(B) Sodium
(C) Zinc
(D) Iron

50. Which of the following is not a member of the second transition series?
(A) Fe
(B) Zr
(C) Pt
(D) Sc

51. Which of the following transition metal ions is diamagnetic? [BSEB, 2009 A]
(A) $Co^{2+}$
(B) $Ni^{2+}$
(C) $Cu^{2+}$
(D) $Zn^{2+}$

52. The percentage of carbon atom in wrought iron (Pitwa Loha) is: [BSEB, 2020 A]
(A) 0.4%
(B) .04%
(C) .02%
(D) .03%

53. Transition metals have complete series of:
(A) 2
(B) 3
(C) 4
(D) 5

54. Which of the following transition metal ions is diamagnetic? [BSEB, 2023 A]
(A) $Ag^{+}$
(B) $Cu^{2+}$
(C) $Zn^{2+}$
(D) $Au^{+}$

55. Which of the following acts as both oxidizing and reducing agent? [BSEB, 2022 A]
(A) $H_{2}S$
(B) $H_{2}SO_{4}$
(C) $SO_{2}$
(D) $SO_{3}$

56. In which of the following is the oxidation state of Mn minimum? [BSEB, 2022 A]
(A) $MnSO_{4}$
(B) $MnO_{2}$
(C) $Mn_{3}O_{4}$
(D) $Mn_{2}O_{7}$

57. The number of unpaired electrons in a molecule of liquid oxygen is: [BSEB, 2025 A]
(A) 0
(B) 2
(C) 3
(D) 4

58. Which of the following metals does not liberate hydrogen gas on reaction with dilute acid? [BSEB, 2020 A]
(A) Fe
(B) Zn
(C) Cu
(D) Mg

59. Elements of which group are called transition elements? [BSEB, 2015 A]
(A) p-block
(B) s-block
(C) d-block
(D) f-block

60. The general electronic configuration of d-block elements is: [BSEB, 2023 A]
(A) $(n-1)d^{1-10} ns^{1}$
(B) $(n-1)d^{1-10} ns^{1-2}$
(C) $(n-1)d^{1-10} ns^{0}$
(D) $ns^{2} (n-1)d^{10}$

61. Which of the following compounds can be colored? [BSEB, 2025 A]
(A) $Ag_{2}SO_{4}$
(B) $CuF_{2}$
(C) $Cu_{2}Cl_{2}$
(D) $MgF_{2}$

62. On placing an iron piece in $CuSO_{4}$ solution, the blue color of the solution changes to: [BSEB, 2018 C]
(A) Black
(B) Green
(C) Brown
(D) Colorless

63. Which shows the maximum oxidation state?
(A) Sc
(B) Fe
(C) Zn
(D) Mn

64. Bell metal is an alloy of:
(A) Cu + Pb
(B) Cu + Sn
(C) Cu + Zn
(D) Cu + Ni

65. Which of the following is liquid at room temperature? [BSEB, 2016 C]
(A) Zn
(B) Hg
(C) Cu
(D) Au

66. The most stable oxidation state of Chromium is:
(A) +5
(B) +3
(C) +2
(D) +4

67. The aqueous solution of which ion is colorless? [BSEB, 2019 C]
(A) $Cu^{1+}$
(B) $Ag^{1+}$
(C) $Fe^{2+}$
(D) $Zn^{2+}$

68. The best way to prevent iron from rusting is: [BSEB, 2021 A]
(A) Making it a cathode
(B) Putting it in saline water
(C) Both ‘A’ and ‘B’
(D) None of these

69. Which of the following is the main impurity found in pig iron?
(A) Graphite
(B) O
(C) S
(D) Si

70. Which of the following gives a yellow or brown precipitate with Nessler’s reagent? [BSEB, 2018 A]
(A) $CO_{2}$
(B) $NH_{3}$
(C) $NaCl$
(D) $KI$

71. Which of the following elements show variable valency?
(A) Group 1 elements
(B) Group 13 elements
(C) Group 3 to 11 elements
(D) Group 18 elements

72. The lanthanide contraction is responsible for the fact that:
(A) Zr and Zn have same radius
(B) Zr and Hf have about same radius
(C) Zr and Nb have same radius
(D) Zr and Y have same radius

73. Which of the following is NOT an actinide? [BSEB, 2022 A]
(A) Curium
(B) Californium
(C) Uranium
(D) Terbium

74. The percentage of carbon atoms in cast iron is:
(A) 04%
(B) 06%
(C) 08%
(D) 10%

75. Atomic numbers of elements in the 3d-transition series are: [BSEB, 2025 A]
(A) 22 to 30
(B) 21 to 30
(C) 21 to 31
(D) 21 to 29

76. Which of the following has the maximum magnetic moment?
(A) $V^{3+}$
(B) $Cr^{3+}$
(C) $Fe^{3+}$
(D) $Co^{3+}$

77. The electronic configuration of Copper (Z = 29) is: [BSEB, 2025 A]
(A) $[Ar] 3d^{9} 4s^{2}$
(B) $[Ar] 3d^{10} 4s^{1}$
(C) $[Ar] 3d^{8} 4s^{2}$
(D) $[Ar] 3d^{10} 4s^{2}$

78. Which metal nitrate gives a colorless gas on thermal decomposition? [BSEB, 2018 A]
(A) $NaNO_{3}$
(B) $Cu(NO_{3})_{2}$
(C) $Ba(NO_{3})_{2}$
(D) $Hg(NO_{3})_{2}$

79. Mn ki +7 oxidation state kis compound mein hoti hai? [BSEB, 2021 A]
(A) $MnO_{2}$
(B) $KMnO_{4}$
(C) $Mn_{2}O_{3}$
(D) $MnCl_{2}$

80. Misch metal ka upyog kisme kiya jata hai?
(A) Steel banane mein
(B) Cigarette lighter banane mein
(C) Rocket fuel mein
(D) None of these

81. Which of the following is an ‘Inner Transition’ element?
(A) Fe
(B) Au
(C) Ce
(D) Hg

82. In the first transition series (3d series), the density increases from:
(A) Sc to Cr
(B) Sc to Fe
(C) Sc to Ni
(D) Sc to Zn

83. Transition elements form complex compounds because of:
(A) Small size of ions
(B) High nuclear charge
(C) Availability of vacant d-orbitals
(D) All of the above

84. In transition elements, the electronic configuration of the outermost shell will be: [BSEB, 2017 A]
(A) $3d^{5}$
(B) $3d^{2}$
(C) $3d^{7}$
(D) $3d^{9}$

85. $Ti^{4+}$ ion ka rang (color) hota hai:
(A) Hara
(B) Neela
(C) Rangheen
(D) Peela

86. Which of the following has the maximum number of unpaired electrons? [BSEB, 2024 A]
(A) $Mg^{2+}$
(B) $Ti^{3+}$
(C) $V^{3+}$
(D) $Fe^{3+}$

87. Which of the following metals has the minimum density?
(A) Zn
(B) Sc
(C) Ti
(D) Cr

88. Kroll’s process is used for the extraction of:
(A) Cu
(B) Ti
(C) Zn
(D) Fe

89. Metal found in free state in nature is: [BSEB, 2021 A]
(A) Gold
(B) Silver
(C) Copper
(D) Sodium

90. Which of the following has the minimum ionic radius of Mn?
(A) $MnO$
(B) $MnO_{2}$
(C) $KMnO_{4}$
(D) $KMnSO_{4}$

91. Which of the following is a common property of transition elements?
(A) They show variable oxidation states
(B) They are all paramagnetic
(C) They form complex compounds
(D) All of the above

92. Oxidation number of Chromium in $[Cr(CO)_{6}]$ is:
(A) 1
(B) 0
(C) 6
(D) 3

93. Which of the following ions is most stable in aqueous solution?
(A) $Mn^{3+}$
(B) $Cr^{3+}$
(C) $V^{3+}$
(D) $Ti^{3+}$

94. Copper is a member of:
(A) First transition series
(B) Second transition series
(C) Third transition series
(D) Fourth transition series

95. Which of the following is NOT a d-block member? [BSEB, 2018 A]
(A) Fe
(B) Co
(C) Al
(D) Ni

96. Pratham sankraman shreni (1st Transition Series) mein sabse adhik paya jane wala tatva hai:
(A) Fe
(B) Cu
(C) Cr
(D) Zn

97. Oxidation number of Fe in $[Fe(CO)_{5}]$ is:
(A) 1
(B) 2
(C) 5
(D) 0

98. Which of the following ions is colored? [BSEB, 2009 A, 2013 A]
(A) $Co^{2+}$
(B) $Ni^{2+}$
(C) $Cu^{2+}$
(D) $Zn^{2+}$

99. Salts of Chromium are colored because:
(A) Chromium is a p-block element
(B) It is a transition element
(C) It is a Lanthanide element
(D) It is an Actinide element

100. Which of the following transition metal ions is paramagnetic? [BSEB, 2024 A]
(A) $Sc^{3+}$
(B) $Cu^{+}$
(C) $Zn^{2+}$
(D) $Cu^{2+}$

Bihar Board Class 12th के (Chemistry/रसायन विज्ञान) = रसायन विज्ञान भाग-1 (Hindi Medium) Book Chapter-8 d- एवं f-ब्लॉक के तत्व के Exam 2026 MCQs Questions Answer Key