Class 12 Chemistry Ch-7 p-block Elements MCQs Exam 2027

COLLECTION: P-BLOCK ELEMENTS

I. Group 15 Elements (Nitrogen Family)

1. The main components of air are: [BSEB, 2025 A]

(A) $CO_2, N_2$ and $O_2$

(B) $N_2, NO$ and $NO_2$

(C) $CO, CO_2$ and $SO_2$

(D) $Cl_2, SO_2$ and $O_2$

2. $PCl_5$ is a/an: [BSEB, 2019 A]

(A) Oxidizing agent

(B) Reducing agent

(C) Both oxidizing and reducing agent

(D) None

3. $H_3PO_3$ is a: [BSEB, 2009 A]

(A) Monobasic acid

(B) Dibasic acid

(C) Tribasic acid

(D) None of these

4. The number of $P-O-P$ bonds in cyclic metaphosphoric acid is: [BSEB, 2010 A, 2018 A]

(A) Two

(B) Zero

(C) Three

(D) Four

5. Which of the following is NOT correct for white phosphorus ($P_4$) molecule? [BSEB, 2018 A]

(A) There are $6\ P-P$ single bonds

(B) There are $4\ P-P$ single bonds

(C) There are 4 lone pairs of electrons

(D) $P-P-P$ angle is $60^\circ$

6. The formula of Nitric acid is: [BSEB, 2019 A, 2019 C]

(A) $HNO_3$

(B) $H_2N_2O_2$

(C) $HNO_2$

(D) $HNO_4$

7. In the reaction $N_2 + 3H_2 \to 2NH_3 + Q\ cals$, increasing the temperature: [BSEB, 2020 A]

(A) Increases the production of ammonia

(B) Decreases the production of ammonia

(C) Has no effect

(D) None of these

8. Chlorine reacts with excess ammonia to form: [BSEB, 2021 A]

(A) $NH_4Cl$

(B) $N_2 + HCl$

(C) $N_2 + NH_4Cl$

(D) $N_2 + NCl_3$

9. White and Yellow Phosphorus are: [BSEB, 2019 A, 2020 A]

(A) Allotropes

(B) Isotopes

(C) Isobars

(D) Isotones

10. Nitric acid is prepared by: [BSEB, 2019 A, 2026]

(A) Contact process

(B) Ostwald’s process

(C) Photosynthesis

(D) Haber’s process

11. The structural formula of Hypophosphorous acid is: [BSEB, 2025 A]

(A) $H_3PO_2$

(B) $H_3PO_3$

(C) $H_3PO_4$ (peroxy)

(D) $H_3PO_4$

12. The most stable oxidation state of Bismuth ($Bi$) is: [BSEB, 2018 A, 2025 A]

(A) +3

(B) +5

(C) Both +3 and +5

(D) None

13. Which oxide of Nitrogen is known as Laughing Gas? [BSEB, 2024 A]

(A) Nitric oxide

(B) Nitrous oxide

(C) Dinitrogen trioxide

(D) Dinitrogen pentaoxide

14. The maximum covalency of Nitrogen is: [BSEB, 2025 A]

(A) 2

(B) 3

(C) 4

(D) 5

15. What is the atomicity of Phosphorus? [BSEB, 2010 A]

(A) 1

(B) 2

(C) 3

(D) 4

16. Which of the following is the strongest base? [BSEB, 2025 A]

(A) $AsH_3$

(B) $SbH_3$

(C) $PH_3$

(D) $NH_3$

17. Which catalyst is used in the manufacture of Ammonia by Haber’s process? [BSEB, 2024 A, 2025 A]

(A) $Al_2O_3$

(B) $Fe + Mo$

(C) $CuO$

(D) $Pt$

18. Which of the following is the molecular formula of Orthophosphoric acid? [BSEB, 2024 A]

(A) $H_3PO_3$

(B) $H_3PO_4$

(C) $HPO_3$

(D) $H_4P_2O_7$

19. Boiling white phosphorus with Potassium Hydroxide produces: [BSEB, 2018 A]

(A) Phosphorus hydroxide

(B) Phosphorus pentoxide

(C) Phosphine

(D) None of these

20. Bone ash is mainly: [BSEB, 2018 A]

(A) Calcium phosphide

(B) Calcium phosphate

(C) Animal charcoal

(D) Phosphorus

21. Nitrogen molecule is inert because: [BSEB, 2018 A]

(A) It is highly electronegative

(B) It has a very small size

(C) It has high dissociation energy

(D) It is stable

22. Nitrogen and Oxygen are: [BSEB, 2019 A]

(A) Metals

(B) Non-metals

(C) Metalloids

(D) None

23. Which of the following is the least basic? [BSEB, 2015 A]

(A) $NCl_3$

(B) $NBr_3$

(C) $NI_3$

(D) $NF_3$

24. Which is a tribasic acid? [BSEB, 2017 A]

(A) $H_3PO_4$

(B) $H_3PO_3$

(C) $H_3PO_2$

(D) $HPO_3$

25. The geometric shape of $PCl_5$ is: [BSEB, 2016 C]

(A) Trigonal bipyramidal

(B) Octahedral

(C) Tetrahedral

(D) None of these

26. $P_4O_{10}$ is widely used as: [BSEB, 2026]

(A) Reducing agent

(B) Preservative

(C) Oxidizing agent

(D) Dehydrating agent

27. Which of the following oxides is most acidic? [BSEB, 2026]

(A) $P_2O_5$

(B) $N_2O_5$

(C) $Sb_2O_5$

(D) $As_2O_5$

28. Which of the following cannot act as a reducing agent? [BSEB, 2026]

(A) $NO_2$

(B) $SO_2$

(C) $ClO_2$

(D) $CO_2$

29. Ammonia changes red litmus paper to which color? [BSEB, 2019 A]

(A) Blue

(B) Green

(C) Black

(D) Yellow

30. Ammonia is dried using which of the following? [BSEB, 2016 A]

(A) Quick lime ($CaO$)

(B) $P_2O_5$

(C) Conc. $H_2SO_4$

(D) Anhydrous $CaCl_2$

31. Which of the following forms of Phosphorus is most stable? [BSEB, 2023 A]

(A) Red phosphorus

(B) White phosphorus

(C) Black phosphorus

(D) None of these

II. Group 16 Elements (Oxygen Family)

32. The formula of Oleum is: [BSEB, 2020 A]

(A) $H_2S_2O_7$

(B) $H_2SO_4$

(C) $H_2SO_3$

(D) $H_2S_2O_8$

33. $H_2SO_4$ is a: [BSEB, 2015 A, 2019 A]

(A) Dibasic acid

(B) Monobasic acid

(C) Monoacidic base

(D) Diacidic base

34. Which other component is present with $H_2SO_4$ in Oleum? [BSEB, 2019 A, 2020 A]

(A) $SO_2$

(B) $SO_3$

(C) $H_2S$

(D) $HSO_4^-$

35. The oxidation state of Sulphur in $SF_6$ is: [BSEB, 2016 C]

(A) +6

(B) -6

(C) +4

(D) -4

36. The oxidation state of Sulphur in $S_8$ is: [BSEB, 2022 A]

(A) +2

(B) +4

(C) +8

(D) 0

37. The hybridization of S in $SO_3$ is: [BSEB, 2025 A]

(A) $sp^2$

(B) $sp^3$

(C) $sp^3d$

(D) $sp^3d^2$

38. Which of the following is a polar compound? [BSEB, 2023 A]

(A) $SO_2$

(B) $SO_3$

(C) $BF_3$

(D) $CO_2$

39. The bleaching action of Sulphur dioxide ($SO_2$) is due to: [BSEB, 2012 A]

(A) Oxidation

(B) Reduction

(C) Hydrolysis

(D) Acidic nature

40. The peroxy acid of Sulphur is: [BSEB, 2026]

(A) $H_2SO_4$

(B) $H_2S_2O_8$

(C) $H_2SO_3$

(D) $H_2S_2O_3$

41. The reaction of Mercury and Ozone produces:

(A) $HgO$

(B) $Hg_2O$

(C) $Hg_2O_2$

(D) None of these

42. The gas which cannot be collected over water is: [BSEB, 2019 A]

(A) $H_2$

(B) $O_2$

(C) $CH_4$

(D) $SO_2$

43. Group 16 elements are called: [BSEB, 2021 A]

(A) Halogens

(B) Chalcogens

(C) Transition elements

(D) Noble gases

44. The element found in Group 16 of the periodic table besides Oxygen is: [BSEB, 2020 A]

(A) Sulphur

(B) Sodium

(C) Iron

(D) Nitrogen

45. Which of the following elements show allotropy? [BSEB, 2024 A]

(A) Oxygen

(B) Sulphur

(C) Selenium

(D) All of these

46. The product formed by the reaction of Sulphur with excess Fluorine is: [BSEB, 2025 A]

(A) $S_1F_2$

(B) $SF_4$

(C) $SF_6$

(D) $(SF)_2$

47. Oxygen and Ozone are: [BSEB, 2015 A]

(A) Isobars

(B) Isomers

(C) Allotropes

(D) Isotopes

48. Which of the following is the least volatile? [BSEB, 2022 A]

(A) $H_2Se$

(B) $H_2Te$

(C) $H_2S$

(D) $H_2O$

49. Peroxy acid of Sulphur is: [BSEB, 2026]

(A) $H_2S_2O_7$

(B) $H_2S_2O_8$

(C) $H_2SO_4$

(D) $H_2SO_3$

50. Which of the following has the highest bond energy? [BSEB, 2024 A, 2026]

(A) $O-O$

(B) $S-S$

(C) $Se-Se$

(D) $Te-Te$

51. The molecule of Sulphur is: [BSEB, 2026]

(A) Diatomic

(B) Tetratomic

(C) Triatomic

(D) Octatomic

52. The formula of Ozone is: [BSEB, 2019 A]

(A) $O_2$

(B) $O_3$

(C) $O_4$

(D) $O$

53. The oxidation state of Sulphur in $H_2S_2O_7$ is: [BSEB, 2021 A]

(A) +4

(B) +2

(C) +6

(D) +5

III. Group 17 Elements (Halogens)

54. Which element is obtained from seaweeds? [BSEB, 2011 A, 2021 A]

(A) Sodium

(B) Iodine

(C) Calcium

(D) Potassium

55. Which of the following is the strongest oxidizing agent? [BSEB, 2012 A, 2016 A, 2020 A]

(A) $F_2$

(B) $Cl_2$

(C) $I_2$

(D) $Br_2$

56. In which of the following does Oxygen have an oxidation state of +2? [BSEB, 2023 A]

(A) $F_2O$

(B) $Cl_2O$

(C) $Na_2O_2$

(D) $Na_2O$

57. Which of the following forms only one oxoacid? [BSEB, 2022 A]

(A) $F_2$

(B) $Cl_2$

(C) $Br_2$

(D) $I_2$

58. Which of the following is the strongest acid? [BSEB, 2016 C, 2018 C]

(A) $BF_3$

(B) $BCl_3$

(C) $BBr_3$

(D) $BI_3$

59. Which of the following halogens does not show positive oxidation state? [BSEB, 2024 A]

(A) $I$

(B) $Br$

(C) $Cl$

(D) $F$

60. Chlorine is an element, not a compound; this was proved by: [BSEB, 2025 A]

(A) Scheele

(B) Priestley

(C) Lavoisier

(D) Davy

61. Reagent used for bleaching cotton clothes is: [BSEB, 2025 A]

(A) Nascent $F_2$

(B) Nascent $Cl_2$

(C) Nascent $Br_2$

(D) Nascent $I_2$

62. The strongest acid is: [BSEB, 2021 A]

(A) $HClO_4$

(B) $HClO_3$

(C) $HClO_2$

(D) $HClO$

63. Which is an essential component of photographic film plates? [BSEB, 2021 A]

(A) Silver nitrate

(B) Silver bromide

(C) Sodium chloride

(D) Oleic acid

64. Which of the following bonds is the strongest? [BSEB, 2021 A]

(A) $F-F$

(B) $Cl-Cl$

(C) $I-I$

(D) $Br-Br$

65. Among HF, HCl, HBr, and HI, the strongest acid is: [BSEB, 2019 A]

(A) $HF$

(B) $HCl$

(C) $HBr$

(D) $HI$

66. The product obtained from the reaction of Silica and Hydrogen Fluoride is: [BSEB, 2018 A]

(A) $SiF_4$

(B) $H_2SiF_6$

(C) $H_2SiF_4$

(D) $H_2SiF_3$

67. Which of the following hydrogen bonds is strongest? [BSEB, 2023 A]

(A) $O-H \dots S$

(B) $S-H \dots O$

(C) $F-H \dots F$

(D) $F-H \dots O$

68. The bleaching property of Chlorine is due to: [BSEB, 2026]

(A) Acidic property

(B) Oxidizing property

(C) Reducing property

(D) Air polluting property

69. Which of the following is the strongest base? [BSEB, 2026]

(A) $ClO_4^-$

(B) $ClO_3^-$

(C) $ClO_2^-$

(D) $ClO^-$

70. Which of the following shows only one oxidation state other than zero? [BSEB, 2026]

(A) $Cl_2$

(B) $F_2$

(C) $I_2$

(D) $Br_2$

71. The correct formula of bleaching powder is: [BSEB, 2014 A]

(A) $Ca(OCl)_2$

(B) $CaOCl_2$

(C) $Ca(OCl)Cl$

(D) All of these

IV. Group 18 Elements (Noble Gases)

72. The shape of $XeF_4$ is: [BSEB, 2015 A, 2024 A]

(A) Angular

(B) Square planar

(C) Octahedral

(D) None of these

73. Which gas mixture is used by divers for respiration? [BSEB, 2021 A]

(A) Nitrogen + Oxygen

(B) Carbon + Oxygen

(C) Helium + Oxygen

(D) Krypton + Oxygen

74. The formula of Helium is: [BSEB, 2019 A]

(A) $He$

(B) $Hi$

(C) $Hm$

(D) All

75. Maximum diffusion capacity is found in: [BSEB, 2015 A]

(A) $He$

(B) $Ne$

(C) $Ar$

(D) $Kr$

76. What is the main source of Helium? [BSEB, 2013 A, 2015 A]

(A) Earth

(B) Coal mines

(C) Sun

(D) Radium

77. Argon is a gas which is: [BSEB, 2019 A, 2019 C]

(A) Diatomic

(B) Monoatomic

(C) Triatomic

(D) Octatomic

78. Noble gas used for filling bulbs is: [BSEB, 2015 A]

(A) $He$

(B) $Ne$

(C) $Ar$

(D) $Kr$

79. Complete hydrolysis of $XeF_6$ gives: [BSEB, 2015 A]

(A) $XeO_3$

(B) $XeOF_4$

(C) $XeO_2F_2$

(D) $Xe$

80. The outer shell electronic configuration of noble gases is: [BSEB, 2024 A, 2026]

(A) $ns^2 np^5$

(B) $ns^2 np^6$

(C) $ns^2 np^4$

(D) $ns^2 np^3$

81. Beside the Sun, what is the main source of Helium on Earth? [BSEB, 2024 A]

(A) Atmosphere

(B) Monazite sand

(C) Petroleum

(D) Coal

82. Noble gases are chemically inert because:

(A) They are monoatomic

(B) They have low boiling points

(C) Their valence shells are completely filled

(D) They are rare elements

83. The lightest and non-inflammable gas is:

(A) $H$

(B) $Ar$

(C) $He$

(D) $Rn$

84. Noble gases are: [BSEB, 2019 A]

(A) Diatomic

(B) Monoatomic

(C) Triatomic

(D) None of these

85. Which of the following compounds is not known? [BSEB, 2019 A]

(A) $XeF_2$

(B) $XeF_4$

(C) $XeF_6$

(D) $XeCl_4$

86. The main source of noble gases is: [BSEB, 2018 A]

(A) Atmosphere

(B) Sea

(C) Rocks

(D) Springs

87. Which of the following does not exist?

(A) $XeOF_4$

(B) $NeF_2$

(C) $XeF_2$

(D) $XeO_3$

88. Which of the following is a radioactive noble gas? [BSEB, 2023 A]

(A) $He$

(B) $Ne$

(C) $Xe$

(D) $Rn$

89. The shape of $XeF_2$ molecule is: [BSEB, 2016 C, 2022 A]

(A) Linear

(B) Square planar

(C) Trigonal planar

(D) Pyramidal

90. Which noble gas forms the maximum number of compounds? [BSEB, 2023 A]

(A) $He$

(B) $Ne$

(C) $Ar$

(D) $Xe$

91. Which noble gas is most easily liquefied? [BSEB, 2026]

(A) $Ar$

(B) $Ne$

(C) $Xe$

(D) $Kr$

V. General Properties & Other Important Questions

92. Hybridization of Carbon in Diamond is: [BSEB, 2016 A]

(A) $sp^3$

(B) $sp^2$

(C) $sp$

(D) $dsp^2$

93. The main ore of Iron is: [BSEB, 2021 A]

(A) Magnetite

(B) Siderite

(C) Hematite

(D) All of these

94. Sulphide ores are concentrated by: [BSEB, 2015 A, 2017 A]

(A) Froth floatation process

(B) Electrolysis

(C) Roasting

(D) None of these

95. Oxidation state of Nickel in $Ni(CO)_4$ is: [BSEB, 2011 A, 2018 A, 2025 A]

(A) 0

(B) 2

(C) 3

(D) 4

96. $Al_2O_3$ is a/an _______ oxide:

(A) Amphoteric

(B) Acidic

(C) Basic

(D) None of these

97. Ore of Mercury is: [BSEB, 2021 A]

(A) Cinnabar

(B) Bauxite

(C) Hematite

(D) None of these

98. Oxidation number of $Fe$ in $K_4[Fe(CN)_6]$ is: [BSEB, 2009 A, 2018 A, 2021 A]

(A) +2

(B) +3

(C) -2

(D) -3

99. Number of $\sigma$ and $\pi$ bonds in $C_2$ molecule is: [BSEB, 2018 A]

(A) 1 $\sigma$ and 1 $\pi$

(B) 1 $\sigma$ and 2 $\pi$

(C) Only 2 $\pi$

(D) 1 $\sigma$ and 3 $\pi$

100. Formula of Copper Pyrite is: [BSEB, 2010 A, 2015 A, 2024 A]

(A) $CuFeS$

(B) $CuFeS_2$

(C) $Cu_2S$

(D) $Cu_2FeS_2$

101. Electronic configuration of Carbon is: [BSEB, 2019 C]

(A) $1s^2, 2s^2, 2p^2$

(B) $1s^2, 2s^2, 2p^1$

(C) $1s^2, 2s^2, 2p^3$

(D) $1s^2, 2s^2, 2p^4$

102. The shape of p-orbital is: [BSEB, 2025 A]

(A) Spherical

(B) Dumb-bell

(C) Double dumb-bell

(D) None of these

103. Which acid is prepared by Salt-cake furnace? [BSEB, 2025 A]

(A) $HF$

(B) $HCl$

(C) $HBr$

(D) $HI$

104. Which molecule has zero dipole moment? [BSEB, 2018 A]

(A) $NF_3$

(B) $BF_3$

(C) $ClO_2$

(D) $CH_2Cl_2$

105. Element showing highest oxidation state in first transition series: [BSEB, 2016 A]

(A) $Ni$

(B) $Cr$

(C) $Fe$

(D) $Mn$

106. Copper is refined by which method? [BSEB, 2017 A]

(A) Electrolytic refining

(B) Zone refining

(C) Chromatography

(D) None of these

107. Group I elements of periodic table are known as: [BSEB, 2019 A]

(A) Alkali metals

(B) Alkaline earth metals

(C) Inert gases

(D) None

108. Number of elements in second period of periodic table is: [BSEB, 2019 A]

(A) 2

(B) 8

(C) 18

(D) 32

109. Oxidation state of Aluminium is: [BSEB, 2019 A]

(A) +3

(B) +2

(C) +1

(D) -3

110. Sodium is a member of which group in the periodic table? [BSEB, 2015 A]

(A) Group I

(B) Group II

(C) Group IV

(D) None of these

111. The element that must be present in organic compounds is: [BSEB, 2016 A]

(A) Oxygen

(B) Carbon

(C) Hydrogen

(D) Nitrogen

112. Formula of tap water is: [BSEB, 2019 C]

(A) $H_2O$

(B) $H_3O$

(C) $H_2O^\oplus$

(D) $D_2O$

113. NaOH is a/an: [BSEB, 2009 A, 2019 C]

(A) Acid

(B) Base

(C) Salt

(D) All

114. Which compound has zero dipole moment? [BSEB, 2023 A]

(A) $CH_3Cl$

(B) $CHCl_3$

(C) $CCl_4$

(D) $CH_2Cl_2$

115. Which of the following oxides is amphoteric? [BSEB, 2019 A]

(A) $Na_2O$

(B) $MgO$

(C) $SO_2$

(D) $ZnO$

116. Gas with the lowest boiling point is: [BSEB, 2022 A, 2023 A]

(A) Hydrogen

(B) Helium

(C) Nitrogen

(D) Argon

117. Symbol of Tin is: [BSEB, 2019 C]

(A) $Sn$

(B) $Tn$

(C) $Ti$

(D) $Fe$

118. Which has the highest bond angle? [BSEB, 2018 C]

(A) $NH_3$

(B) $H_2S$

(C) $BF_3$

(D) $CH_4$

119. Element found in sea water is: [BSEB, 2016 A]

(A) Magnesium

(B) Sodium

(C) Iodine

(D) None of these

120. Which metal becomes passive in Conc. $HNO_3$? [BSEB, 2018 C]

(A) $Cu$

(B) $Zn$

(C) $Al$

(D) $Pb$

121. Which of the following is colored? [BSEB, 2019 A]

(A) $NH_3$

(B) $N_2O$

(C) $NO$

(D) $NO_2$

122. In Smelting, reduction of metal oxide involves: [BSEB, 2020 A]

(A) $Al$

(B) $C$

(C) $Mg$

(D) $CO$

123. Substance showing paramagnetism is: [BSEB, 2021 A]

(A) $H_2O$

(B) $O_2$

(C) $NaCl$

(D) $C_6H_6$

124. Which compound has the highest dipole moment? [BSEB, 2018 C]

(A) $HF$

(B) $HCl$

(C) $HBr$

(D) $HI$

125. Which has the highest ionization potential? [BSEB, 2012 A]

(A) $Al$

(B) $P$

(C) $Si$

(D) $Mg$

126. $H_3PO_4$ is a: [BSEB, 2015 A]

(A) Monobasic acid

(B) Dibasic acid

(C) Tribasic acid

(D) None of these

127. Which of the following does not form hydrogen bond? [BSEB, 2011 A, 2015 A, 2021 A]

(A) $NH_3$

(B) $H_2O$

(C) $HCl$

(D) $HF$

128. Adding $P_4O_{10}$ to Conc. $H_2SO_4$ produces: [BSEB, 2024 A]

(A) $SO_2$

(B) $SO_3$

(C) $H_3PO_4$

(D) $HPO_3$

129. $p\pi-d\pi$ bonding is found in which of the following? [BSEB, 2021 A]

(A) $CO_3^{2-}$

(B) $NO_3^-$

(C) $SO_4^{2-}$

(D) $BO_3^{3-}$

130. Aqua regia is a mixture of: [BSEB, 2016 A]

(A) $3\ HCl : 1\ HNO_3$

(B) $2\ HCl : 1\ HNO_3$

(C) $1\ HCl : 1\ HNO_3$

(D) $3\ HCl : 3\ HNO_3$

131. Which halogen is most reactive? [BSEB, 2017 A]

(A) $F_2$

(B) $Cl_2$

(C) $Br_2$

(D) $I_2$

132. Correct formula of bleaching powder is: [BSEB, 2014 A]

(A) $CaOCl_2$

(B) $Ca(OCl)Cl$

(C) $CaOCl$

(D) None of these

133. Which of the following ions is colorless? [BSEB, 2023 A]

(A) $Cu^{2+}$

(B) $Ti^{3+}$

(C) $V^{2+}$

(D) $Sc^{3+}$

134. Geometry of $XeF_2$ is: [BSEB, 2022 A]

(A) Linear

(B) Angular

(C) Square planar

(D) Pyramidal

135. Strongest base is: [BSEB, 2026]

(A) $ClO_4^-$

(B) $ClO_3^-$

(C) $ClO_2^-$

(D) $ClO^-$

136. Reaction of Mercury ($Hg$) with Ozone produces: [BSEB, 2026]

(A) $HgO$

(B) $HgO_2$

(C) $Hg_2O$

(D) None of these

137. Reason for bleaching property of Chlorine is: [BSEB, 2026]

(A) Oxidizing property

(B) Acidic property

(C) Reducing property

(D) Air pollutant property

138. Outer configuration of inert gases is: [BSEB, 2026]

(A) $ns^2 np^6$

(B) $ns^2 np^5$

(C) $ns^2 np^4$

(D) $ns^2 np^2$

139. $P_4O_{10}$ is used as: [BSEB, 2026]

(A) Dehydrating agent

(B) Oxidizing agent

(C) Reducing agent

(D) Preservative

140. Which of the following is most acidic? [BSEB, 2026]

(A) $N_2O_5$

(B) $P_2O_5$

(C) $As_2O_5$

(D) $Sb_2O_5$

141. Highest bond energy is found in: [BSEB, 2026]

(A) $S-S$

(B) $O-O$

(C) $Se-Se$

(D) $Te-Te$

142. Sulphur molecule is: [BSEB, 2026]

(A) Octatomic

(B) Diatomic

(C) Triatomic

(D) Tetratomic

143. Which shows only one oxidation state? [BSEB, 2026]

(A) $F_2$

(B) $Cl_2$

(C) $Br_2$

(D) $I_2$

144. Which cannot act as a reducing agent? [BSEB, 2026]

(A) $CO_2$

(B) $SO_2$

(C) $NO_2$

(D) $ClO_2$

145. Noble gas which is easily liquefied: [BSEB, 2026]

(A) $Xe$

(B) $He$

(C) $Ne$

(D) $Ar$

146. Peroxy acid of Sulphur is: [BSEB, 2026]

(A) $H_2S_2O_8$

(B) $H_2S_2O_7$

(C) $H_2SO_4$

(D) $H_2SO_3$

147. Method of making Nitric acid from Ammonia: [BSEB, 2026]

(A) Ostwald’s method

(B) Birkeland-Eyde method

(C) Laboratory method

(D) All of these

148. Gas that cannot be collected over water: [BSEB, 2026]

(A) $SO_2$

(B) $O_2$

(C) $H_2$

(D) $CH_4$

149. Bleaching property of Chlorine is due to: [BSEB, 2026]

(A) Oxidation property

(B) Acidic property

(C) Reduction property

(D) None of these

150. Outer configuration of noble gases: [BSEB, 2026]

(A) $ns^2 np^6$

(B) $ns^2 np^5$

(C) $ns^2 np^4$

(D) $ns^2 np^2$

151. Shape of $XeF_4$ is: [BSEB, 2015 A]

(A) Square planar

(B) Angular

(C) Octahedral

(D) Linear

152. Which of the following is the most powerful oxidizing agent? [BSEB, 2012 A]

(A) $F_2$

(B) $Cl_2$

(C) $Br_2$

(D) $I_2$

153. Main source of Helium besides the Sun: [BSEB, 2024 A]

(A) Monazite sand

(B) Earth

(C) Atmosphere

(D) Coal

154. Which has highest bond energy? [BSEB, 2024 A]

(A) $S-S$

(B) $O-O$

(C) $Se-Se$

(D) $Te-Te$

155. Oxidation state of $Ni$ in $Ni(CO)_4$: [BSEB, 2025 A]

(A) 0

(B) 2

(C) 4

(D) 3

156. Hybridization of $S$ in $SO_3$: [BSEB, 2025 A]

(A) $sp^2$

(B) $sp^3$

(C) $sp$

(D) $dsp^2$

157. $Al_2O_3$ is a/an _______ oxide:

(A) Amphoteric

(B) Acidic

(C) Basic

(D) None

158. Formula of Ozone: [BSEB, 2019 A]

(A) $O_3$

(B) $O_2$

(C) $O_4$

(D) $O$

159. Ammonia is dried by: [BSEB, 2016 A]

(A) $CaO$

(B) $P_2O_5$

(C) $H_2SO_4$

(D) $CaCl_2$

160. Acid made by Salt-cake furnace: [BSEB, 2025 A]

(A) $HCl$

(B) $HF$

(C) $HBr$

(D) $HI$