\section{LEVEL-1 \\ TOPIC 1: Electrovalent, Covalent and Coordinate Bonding}

1. Which of the following combination will form an electrovalent bond ?

1) \(\mathrm{P}\) and \(\mathrm{Cl}\)

2) \(\mathrm{NH}_{3}\) and \(\mathrm{BF}_{3}\)

3) \(\mathrm{H}\) and \(\mathrm{Ca}\)

4) \(\mathrm{H}\) and \(\mathrm{S}\)

2. Which has a giant covalent structure?

1) \(\mathrm{PbO}_{2}\)

2) \(\mathrm{SiO}_{2}\)

3) \(\mathrm{NaCl}\)

4) \(\mathrm{AlCl}_{3}\)

3. Which one of the following contains a co-ordinate covalent bond ?

1) \(\mathrm{H}_{2} \mathrm{O}\)

2) \(\mathrm{HCl}\)

3) \(\mathrm{BaCl}_{2}\)

4) \(\mathrm{N}_{2} \mathrm{H}_{5}^{+}\)

4. The number of dative bonds in sulphuric acid molecule is

1) 0

2) 1

3) 2

4) 4

5. Which of the following statements is not true about covalent compounds?

1) They may exhibit space isomerism

2) They have low melting and boiling points

3) They show ionic reactions

4) They show molecular reactions

6. Indicate the nature of bonding in \(\mathrm{CCl}_{4}\) and \(\mathrm{CaH}_{2}\)

1) Covalent in \(\mathrm{CCl}_{4}\) and electrovalent in \(\mathrm{CaH}_{2}\)

2) Electrovalent in both \(\mathrm{CCl}_{4}\) and \(\mathrm{CaH}_{2}\)

3) Covalent in both \(\mathrm{CCl}_{4}\) and \(\mathrm{CaH}_{2}\)

4) Electrovalent in \(\mathrm{CCl}_{4}\) and covalent in \(\mathrm{CaH}_{2}\)

7. Lattice energy of an ionic compound depends upon

1) charge on the ion and size of the ion

2) packing of ions only

3) size of the ion only

4) charge on the ion only

8. Among the following which compound will show the highest lattice energy ?

1) \(\mathrm{KF}\)

2) \(\mathrm{NaF}\)

3) \(\operatorname{CsF}\)

4) \(\mathrm{RbF}\)

9. The compound that has the highest ionic character associated with the \(\mathrm{X}-\mathrm{Cl}\) bond is:

1) \(\mathrm{PCl}_{5}\)

2) \(\mathrm{BCl}_{3}\)

3) \(\mathrm{CCl}_{4}\)

4) \(\mathrm{SiCl}_{4}\)

10. Which combination of atoms can form a polar covalent bond?

1) \(\mathrm{H}\) and \(\mathrm{H}\)

2) \(\mathrm{H}\) and \(\mathrm{F}\)

3) \(\mathrm{N}\) and \(\mathrm{N}\)

4) Na and \(F\)

11. Which of the following pairs will form the most stable ionic bond ?

1) \(\mathrm{Na}\) and \(\mathrm{Cl}\)

2) \(\mathrm{Mg}\) and \(\mathrm{F}\)

3) \(\mathrm{Li}\) and \(\mathrm{F}\)

4) \(\mathrm{Na}\) and \(\mathrm{F}\)

12. In which of the following species central atom is NOT surrounded by exactly 8 valence electrons?

1) \(\mathrm{BF}_{4}^{-}\)

2) \(\mathrm{NCl}_{3}\)

3) \(\mathrm{PCl}_{4}^{+}\)

4) \(\mathrm{SF}_{4}\)

13. Which of the following does not apply to metallic bond ?

1) Overlapping valence orbitals

2) Mobile valency electrons

3) Delocalized electrons

4) Highly directed bonds.

14. Which set contains only covalently bonded molecules?

1) \(\mathrm{BCl}_{3}, \mathrm{SiCl}_{4}, \mathrm{PCl}_{3}\)

2) \(\mathrm{NH}_{4} \mathrm{Br}, \mathrm{N}_{2} \mathrm{H}_{4}, \mathrm{HBr}\)

3) \(\mathrm{I}_{2}, \mathrm{H}_{2} \mathrm{~S}, \mathrm{NaI}\)

4) \(\mathrm{Al}, \mathrm{O}_{3}, \mathrm{As}_{4}\)

15. Amongst \(\mathrm{LiCl}, \mathrm{RbCl}, \mathrm{BeCl}_{2}\) and \(\mathrm{MgCl}_{2}\) the compounds with the greatest and the least ionic character, respectively are:

1) \(\mathrm{LiCl}\) and \(\mathrm{RbCl}\)

2) \(\mathrm{RbCl}\) and \(\mathrm{BeCl}_{2}\)

3) \(\mathrm{MgCl}_{2}\) and \(\mathrm{BeCl}_{2}\)

4) \(\mathrm{RbCl}\) and \(\mathrm{MgCl}_{2}\)

16. In ionic solids how crystal structure get stabilized

1) By the energy released in the formation of crystal lattice.

2) By achieving octet of electrons around the ionic species in gaseous state.

3) By electron gain enthalpy and the ionization enthalpy.

4) None of these

17. Which of the following statement is correct?

1) \(\mathrm{FeCl}_{2}\) is more covalent than \(\mathrm{FeCl}_{3}\).

2) \(\mathrm{FeCl}_{3}\) is more covalent than \(\mathrm{FeCl}_{2}\).

3) Both \(\mathrm{FeCl}_{2}\) and \(\mathrm{FeCl}_{3}\) are equally covalent. 4) \(\mathrm{FeCl}_{2}\) and \(\mathrm{FeCl}_{3}\) do not have any covalent character. 18. A pair of compounds which has odd electrons in the group \(\mathrm{NO}, \mathrm{CO}, \mathrm{ClO}_{2}, \mathrm{~N}_{2} \mathrm{O}_{5}, \mathrm{SO}_{2}\) and \(\mathrm{O}_{3}\) are

1) \(\mathrm{NO}\) and \(\mathrm{ClO}_{2}\)

2) \(\mathrm{CO}\) and \(\mathrm{SO}_{2}\)

3) \(\mathrm{ClO}_{2}\) and \(\mathrm{CO}\)

4) \(\mathrm{SO}_{2}\) and \(\mathrm{O}_{3}\)

19. Which of the following molecule(s) obey the octet rule?

(i) \(\left[\mathrm{BF}_{4}\right]^{-}\), (ii) \(\left[\mathrm{AlCl}_{4}\right]^{-}\), (iii) \(\mathrm{SO}_{2}\), (iv) \(\mathrm{CCl}_{4}\)

1) (i), (ii), (iii), (iv)

2) (ii), (iii), (iv)

3) (i), (iii), (iv)

4) (i), (ii), (iv)

20. In the cyanide ion, the formal negative charge is on

1) \(\mathrm{C}\)

2) \(\mathrm{N}\)

3) Both \(C\) and \(N\) 4) resonate between \(C\) and \(N\)

21. Among the following, the species having the smallest bond order is

1) \(\mathrm{NO}^{-}\)

2) \(\mathrm{NO}^{+}\)

3) \(\mathrm{O}_{2}\)

4) \(\mathrm{NO}\)

22. The bond length of \(\mathrm{C}=\mathrm{O}\) bond in \(\mathrm{CO}\) is \(1.20 \AA\) and in \(\mathrm{CO}_{2}\) it is \(1.34 \AA\). Then \(\mathrm{C}=\mathrm{O}\) bond length in \(\mathrm{CO}_{3}^{2-}\) will be

1) \(1.50 \AA\)

2) \(1.34 \AA\)

3) \(1.29 \AA\)

4) \(0.95 \AA\)

23. Which one of the following pairs of molecules will have permanent dipole moments for both members ?

1) \(\mathrm{NO}_{2}\) and \(\mathrm{CO}_{2}\)

2) \(\mathrm{NO}_{2}\) and \(\left.\mathrm{O}_{3} 3\right) \mathrm{SiF}_{4}\) and \(\mathrm{CO}_{2}\)

4) \(\mathrm{SiF}_{4}\) and \(\mathrm{NO}_{2}\)

24. Which of the following structure represents structure of \(\mathrm{O}_{3}\) more accurately?

III

1) I and III only

2) II and III only

3) I and II only

4) All

25. Which of the following salt shows maximum covalent character?

1) \(\mathrm{AlCl}_{3}\)

2) \(\mathrm{MgCl}_{2}\)

3) \(\mathrm{CsCl}\)

4) \(\mathrm{LaCl}_{3}\)

26. Pauling's electronegativity values for elements are useful in predicting :

1) polarity of bonds in molecules

2) ionic and covalent nature of bonds

3) coordination number

4) both 1) and 2)

27. The molecule which has zero dipole moment is

1) \(\mathrm{CH}_{3} \mathrm{Cl}\)

2) \(\mathrm{NF}_{3}\)

3) \(\mathrm{BF}_{3}\)

4) \(\mathrm{ClO}_{2}\)

28. Which bond angle q would result in the maximum dipole moment for the triatomic molecule YXY

1) \(q=90^{\circ}\)

2) \(q=120^{\circ}\)

3) \(q=150^{\circ}\)

4) \(q=180^{\circ}\)

29. Polarisibility of halide ions increases in the order

1) \(\mathrm{F}^{-}, \mathrm{I}^{-}, \mathrm{Br}^{-}, \mathrm{Cl}^{-}\)

2) \(\mathrm{Cl}^{-}, \mathrm{Br}^{-}, \mathrm{I}^{-}, \mathrm{F}^{-}\)

3) \(\mathrm{I}^{-}, \mathrm{Br}^{-}, \mathrm{Cl}^{-}, \mathrm{F}^{-}\)

4) \(\mathrm{F}^{-}, \mathrm{Cl}^{-}, \mathrm{Br}^{-}, \mathrm{I}^{-}\)

30. If one assumes linear structure instead of bent structure for water, then which one of the following properties cannot be explained?

1) The formation of intermolecular hydrogen bond in water.

2) The high boiling point of water.

3) Solubility of polar compounds in water.

4) Ability of water to form coordinate covalent bond.

\section{TOPIC 3: VSEPR Theory, VBT Theory and Hybridization}

31. The angle between the overlapping of one s-orbital and one \(p\)-orbital is

1) \(180^{\circ}\)

2) \(120^{\circ}\)

3) \(109^{\circ} 28^{\prime}\)

4) \(120^{\circ} 60^{\prime}\)

32. Equilateral shape has

1) \(s p\) hybridisation

2) \(s p^{2}\) hybridisation

3) \(s p^{3}\) hybridisation

4) None of these

33. Which one of the following has the shortest carbon-carbon bond length ?

1) Benzene

2) Ethene

3) Ethyne

4) Ethane

34. Which of the following is the correct increasing order of lone pair of electrons on the central atom? 

1) \(\mathrm{IF}_{7}<\mathrm{IF}_{5}<\mathrm{CIF}_{3}<\mathrm{XeF}_{2}\)

2) \(\mathrm{IF}_{7}<\mathrm{XeF}_{2}<\mathrm{CIF}_{2}<\mathrm{IF}_{5}\)

3) \(\mathrm{IF}_{7}<\mathrm{CIF}_{3}<\mathrm{XeF}_{2}<\mathrm{IF}_{5}\)

4) \(\mathrm{IF}_{7}<\mathrm{XeF}_{2}<\mathrm{IF}_{5}<\mathrm{CIF}_{3}\)

35. In which one of the following molecules the central atom is said to adopt \(s p^{2}\) hybridization?

1) \(\mathrm{BeF}_{2}\)

2) \(\mathrm{BF}_{3}\)

3) \(\mathrm{C}_{2} \mathrm{H}_{2}\)

4) \(\mathrm{NH}_{3}\)

36. Which of the following two are isostructural?

1) \(\mathrm{NH}_{3}, \mathrm{BF}_{3}\)

2) \(\mathrm{PCl}_{5}, \mathrm{ICl}_{5}\)

3) \(\mathrm{XeF}_{2}, \mathrm{IF}_{2}^{-}\)

4) \(\mathrm{CO}_{3}^{-2}, \mathrm{SO}_{3}^{2-}\)

37. The decreasing values of bond angles from NH3 \(\left(106^{\circ}\right)\) to \(\mathrm{SbH} 3\left(101^{\circ}\right)\) down group-15 of the periodic table is due to

1) decreasing \(b p-b p\) repulsion

2) decreasing electronegativity

3) increasing \(b p-b p\) repulsion

4) increasing \(l p\) - \(b p\) repulsion

38. The shape of \(\mathrm{ClO}_{3}\) - ion according to Valence Shell Electron Pair Repulsion (VSEPR) theory will be

1) planar triangular

2) pyramidal

3) tetrahedral

4) square planar

39. Which of the following molecules has trigonal planar geometry?

1) \(\mathrm{BF}_{3}\)

2) \(\mathrm{NH}_{3}\)

3) \(\mathrm{PCl}_{3}\)

4) \(\mathrm{IF}_{3}\)

40. Linear combination of two hybridized orbitals belonging to two atoms and each having one electron leads to a

1) sigma bond

2) double bond

3) co-ordinate covalent bond

4) pi bond.

41. Which of the following statements is not correct for sigma and pi-bonds formed between two carbon atoms?

1) Sigma-bond determines the direction between carbon atoms but a pi-bond has no primary effect in this regard

2) Sigma-bond is stronger than a pi-bond

3) Bond energies of sigma- and pi-bonds are of the order of \(264 \mathrm{~kJ} / \mathrm{mol}\) and \(347 \mathrm{~kJ} / \mathrm{mol}\), respectively

4) Free rotation of atoms about a sigma-bond is allowed but not in case of a pi-bond

42. How many \(s\) and \(p\) bonds are present in toluene?

1) \(3 \pi+8 \sigma\)

2) \(3 \pi+10 \sigma\)

3) \(3 \pi+15 \sigma\)

4) \(6 \pi+3 \sigma\)

43. The number of lone pair and bond pair of electrons on the sulphur atom in sulphur dioxide molecule are respectively

1) 1 and 3

2) 4 and 1

3) 3 and 1

4) 1 and 2

44. How many sigma bonds are in a molecule of diethyl ether, \(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OC}_{2} \mathrm{H}_{5}\)

1) 14

2) 12

3) 8

4) 16

45. Which of the following statements is not correct?

1) Hybridisation is the mixing of atomic orbitals prior to their combining into molecular orbitals

2) \(s p^{2}\) hybrid orbitals are formed from two \(p\)-atomic orbitals and one \(s\)-orbital

3) \(d^{2} s p^{3}\) hybrid orbitals are directed towards the corners of a regular octahedron

4) \(d s p^{3}\) hybrid orbitals are all at \(90^{\circ}\) to one another

46. Which of the following species has a linear shape ?

1) \(\mathrm{SO}_{2}\)

2) \(\mathrm{NO}_{2}^{+}\)

3) \(\mathrm{CH}_{4}\)

4) \(\mathrm{NO}_{2}^{-}\)

47. Using VSEPR theory, predict the species which has square pyramidal shape

1) \(\mathrm{SnCl}_{2}\)

2) \(\mathrm{CCl}_{4}\)

3) \(\mathrm{SO}_{3}\)

4) \(\mathrm{BrF}_{5}\)

48. Amongst the following, the molecule/ion that is linear is :

1) \(\mathrm{SO}_{2}\)

2) \(\mathrm{CO}_{2}\)

3) \(\mathrm{ClO}_{2}^{-}\)

4) \(\mathrm{NO}_{2}^{-}\)

49. Which of the following structure is most stable ?

Choose the correct option.

1) Only I

2) Only II

3) Only III

4) All three have same stability

50. The true statements from the following are 1. \(\mathrm{PH}_{5}\) and \(\mathrm{BiCl}_{5}\) do not exist

3. Electrons travel with the speed of light 5. \(\mathrm{I}_{3}^{+}\)has bent geometry

1) 1,3

2) \(1,2,5\)

3) \(1,3,5\)

4) \(1,2,4\)

51. The hybrid state of \(\mathrm{S}\) in \(\mathrm{SO}_{3}\) is similar to that of

2. \(\mathrm{p} \pi-\mathrm{d} \pi\) bond is present in \(\mathrm{SO}_{2}\)

4. \(\mathrm{SeF}_{4}\) and \(\mathrm{CH}_{4}\) have same shape

1) \(\mathrm{C}\) in \(\mathrm{C}_{2} \mathrm{H}_{2}\)

2) \(\mathrm{C}\) in \(\mathrm{C}_{2} \mathrm{H}_{4}\)

3) \(\mathrm{C}\) in \(\mathrm{CH}_{4}\)

4) \(\mathrm{C}\) in \(\mathrm{CO}_{2}\)

52. Allyl cyanide molecule contains

1) 9 sigma bonds, 4 pi bonds and no lone pair

2) 9 sigma bonds, 3 pi bonds and one lone pair

3) 8 sigma bonds, 5 pi bonds and one lone pair

4) 8 sigma bonds, 3 pi bonds and two lone pairs

53. All bond angles are exactly equal to \(109^{\circ} 28^{\text {! }}\) in :

1) methyl chloride 2) iodoform

3) chloroform

4) carbon tetrachloride

54. Which has the least bond angle

1) \(\mathrm{NH}_{3}\)

2) \(\mathrm{BeF}_{2}\)

3) \(\mathrm{H}_{2} \mathrm{O}\)

4) \(\mathrm{CH}_{4}\)

55. The shape of \(\mathrm{IF}_{6}^{-}\)is :

1) Trigonally distorted octahedron

2) Pyramidal

3) Octahedral

4) Square antiprism

56. Which of the following statements is not correct?

1) Double bond is shorter than a single bond

2) Sigma bond is weaker than a \(p\) (pi) bond

3) Double bond is stronger than a single bond

4) Covalent bond is stronger than hydrogen bond

57. In which of the following pair both the species have \(s p^{3}\) hybridization?

1) \(\mathrm{H}_{2} \mathrm{~S}, \mathrm{BF}_{3}\)

2) \(\mathrm{SiF}_{4}, \mathrm{BeH}_{2}\)

3) \(\mathrm{NF}_{3}, \mathrm{H}_{2} \mathrm{O}\)

4) \(\mathrm{NF}_{3}, \mathrm{BF}_{3}\)

58. Which of the following represents zero overlap of atomic orbitals.

(d) All of these

59. The structure of the noble gas compound \(\mathrm{XeF}_{4}\) is :

1) square planar

2) distorted tetrahedral

3) tetrahedral

4) octahedral

60. Which of the following pairs of species have identical shapes?

1) \(\mathrm{NO}_{2}^{+}\)and \(\mathrm{NO}_{2}^{-}\)

2) \(\mathrm{PCl}_{5}\) and \(\mathrm{BrF}_{5}\)

3) \(\mathrm{XeF}_{4}\) and \(\mathrm{ICI}_{4}^{-}\)

4) \(\mathrm{TeCl}_{4}\) and \(\mathrm{XeO}_{4}\)

61. Amongst \(\mathrm{NO}_{3}^{-}, \mathrm{AsO}_{3}^{3-}, \mathrm{CO}_{3}^{2-}, \mathrm{ClO}_{3}^{-}, \mathrm{SO}_{3}^{2-}\) and \(\mathrm{BO}_{3}^{3-}\), the non-planar species are

1) \(\mathrm{CO}_{3}^{2-}, \mathrm{SO}_{3}^{2-}, \mathrm{BO}_{3}^{3-}\)

2) \(\mathrm{AsO}_{3}^{3-}, \mathrm{ClO}_{3}^{-}, \mathrm{SO}_{3}^{2-}\)

3) \(\mathrm{NO}_{3}^{-}, \mathrm{CO}_{3}^{2-}, \mathrm{BO}_{3}^{3-}\)

4) \(\mathrm{SO}_{3}^{2-}, \mathrm{NO}_{3}^{-}, \mathrm{BO}_{3}^{3-}\)

62. What is the shape of the \(\mathrm{IBr}_{2}^{-}\)ion?

1) Linear

2) Bent shape with bond angle of about \(90^{\circ}\)

3) Bent shape with bond angle of about \(109^{\circ}\)

4) Bent shape with bond angle of about \(120^{\circ}\)

63. According to VSEPR theory, in which species do all the atoms lie in the same plane?

1. \(\mathrm{CH}_{3}^{+}\)

2. \(\mathrm{CH}_{3}^{-}\)

1) 1 only

2) 2 only

3) both 1 and 2

4) neither 1 nor 2

64. Which bonds are formed by a carbon atom with \(s p^{2}\)-hybridisation?

1) \(4 \pi\)-bonds

2) \(2 \pi\)-bonds and \(2 \sigma\)-bonds \(\quad\) 3) \(1 \pi\)-bonds and \(3 \sigma\)-bonds

4) \(4 \sigma\)-bonds

65. \(\mathrm{SF}_{2}, \mathrm{SF}_{4}\) and \(\mathrm{SF}_{6}\) have the hybridisation at sulphur atom respectively as :

1) \(s p^{2}, s p^{3}, s p^{2} d^{2}\)

2) \(s p^{3}, s p^{3}, s p^{3} d^{2}\)

3) \(s p^{3}, s p^{3} d, s p^{3} d^{2}\)

4) \(s p^{3}, s p d^{2}, d^{2} s p^{3}\)

66. The strength of bonds formed by \(s-s, p-p\) and \(s-p\) overlap is in the order of

1) \(s-p>s-s>p-p\)

2) \(p-p>s-s>s-p\)

3) \(s-s>p-p>s-p\)

4) \(s-s>s-p>p-p\) 

\section{For more editable material contact \(@ 8977304976\)}

\section{TOPIC 4: MOT and Hydrogen Bonding}

67. The bond order in \(\mathrm{N}_{2}^{+}\)is

1) 1.5

2) 3.0

3) 2.5

4) 2.0

68. The molecular electronic configuration of \(\mathrm{H}_{2}^{+}\)ion is?

1) \((\sigma 1 \mathrm{~s})^{2}\)

2) \((\sigma 1 \mathrm{~s})^{2}\left(\sigma^{*} 1 s\right)^{2}\)

3) \((\sigma 1 s)^{2}\left(\sigma^{*} 1 s\right)^{1}\)

4) \((\sigma 1 \mathrm{~s})^{3}\)

69. In the change of \(\mathrm{NO}^{+}\)to \(\mathrm{NO}\), the electron is added to

1) \(\sigma\) - orbital

2) \(\pi\)-orbital

3) \(\sigma^{*}\) - orbital

4) \(\pi^{*}\) - orbital

70. The correct statement with regard to \(\mathrm{H}^{+}\)and \(\mathrm{H}^{-}\)is

1) Both \(\mathrm{H}^{+}\)and \(\mathrm{H}^{-}\)do not exist

2) \(\mathrm{H}_{2}^{-}\)is more stable than \(\mathrm{H}_{2}^{+}\)

3) \(\mathrm{H}_{2}^{+}\)is more stable than \(\mathrm{H}_{2}^{-}\)

4) Both \(\mathrm{H}_{2}^{+}\)and \(\mathrm{H}_{2}^{-}\)are equally stable

71. If \(\mathrm{N}_{\mathrm{x}}\) is the number of bonding orbitals of an atom and \(\mathrm{N}_{\mathrm{y}}\) is the number of antibonding orbitals, then the molecule/atom will be stable if

1) \(N_{x}>N_{y}\)

2) \(\mathrm{N}_{\mathrm{x}}=\mathrm{N}_{\mathrm{y}}\)

3) \(\mathrm{N}_{\mathrm{x}}<\mathrm{N}_{\mathrm{y}}\)

4) \(\mathrm{N}_{\mathrm{x}} \leq \mathrm{N}_{\mathrm{y}}\)

72. In an anti-bonding molecular orbital, electron density is minimum

1) around one atom of the molecule

2) between the two nuclei of the molecule

3) at the region away from the nuclei of the molecule

4) at no place

73. When two atomic orbitals combine, they form

1) one molecular orbital

2) two molecular orbital

3) three molecular orbital

4) four molecular orbital

74. Of the following hydrides which one has the lowest boiling point?

1) \(\mathrm{AsH}_{3}\)

2) \(\mathrm{SbH}_{3}\)

3) \(\mathrm{PH}_{3}\)

4) \(\mathrm{NH}_{3}\)

75. Which one of the following is the correct order of interactions?

1) covalent \(<\) hydrogen bonding \(<\) van der Waals \(<\) dipoledipole

2) van der Waals \(<\) hydrogen bonding \(<\) dipole-dipole \(<\) covalent

3) van der Waals \(<\) dipole-dipole \(<\) hydrogen bonding \(<\) covalent

4) dipole-dipole \(<\) van der Waals \(<\) hydrogen bonding \(<\) covalent

76. An ether is more volatile than an alcohol having the same molecular formula. This is due to

1) alcohols having resonance structures

2) intermolecular hydrogen bonding in ethers

3) intermolecular hydrogen bonding in alcohols

4) dipolar character of ethers

77. Paramagnetism is exhibited by molecules

1) not attracted into a magnetic field

2) containing only paired electrons

3) carrying a positive charge

4) containing unpaired electrons

78. Hydrogen bonding is maximum in :

1) \(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}\)

2) \(\mathrm{CH}_{3} \mathrm{OCH}_{3}\)

3) \(\left(\mathrm{CH}_{3}\right)_{2} \mathrm{C}=\mathrm{O}\)

4) \(\mathrm{CH}_{3} \mathrm{CHO}\)

79. What is the dominant intermolecular force or bond that must be overcome in converting liquid \(\mathrm{CH}_{3} \mathrm{OH}\) to a gas?

1) Dipole-dipole interaction

2) Covalent bonds

3) London dispersion force

4) Hydrogen bonding

80. In \(\mathrm{O}_{2}^{-}, \mathrm{O}_{2}\) and \(\mathrm{O}_{2}^{-2}\) molecular species, the total number of antibonding electrons respectively are

1) \(7,6,8\)

2) \(1,0,2\)

3) \(6,6,6\)

4) \(8,6,8\)