27
CHAPTER
CHEMICAL BONDING AND
MOLECULAR STRUCTURE
1. The angle between the overlapping of one sorbital and one p-orbital is [1988]
(a) °180
(b) °120
(c) °109 , 28'
(d) °120, °60
ANS: (A)
2. Equilateral shape has [1988]
(a) sp hybridisation
(b) sp2 hybridisation
(c) sp3 hybridisaiton
(d) sp3 hybridisation
Ans: (b)
3. Which of the following molecule does not
have a linear arrangement of atoms?
(a) H2 S
(b) C2H2
(c) BeH 2
(d) CO2
Ans: (a)
4. Which of the following does not apply to
metallic bond?
(a) Overlapping valence orbitals
(b) Mobile valency electrons
(c) Delocalized electrons
(d) Highly directed bonds.
Ans: (d)
5. In which one of the following molecules the
central atom said to adopt sp 2 hybridization?
(a) BeF 2
(b) BF 3
(c) C2H2
(d) NH3
Ans: (b)
6. H2O has a non zero dipole moment while
BeF 2 has zero dipole moment because
(a) H2O molecule is linear while BeF 2 is bent
(b) BeF 2 molecule is linear while H 2O is bent
(c) Fluorine has more electronegativity than
oxygen
(d) Beryllium has more electronegativity than
oxygen.
Chapterwise Previous year Qs
Ans: (b)
7. Among LiCl, BeCl 2 BCl3 and CCl4, the covalent
bond character follows the order
(a) LiCl < BeCl2 > BCl3 > CCl4
(b) BeCl2 < BCl3 < CCl4 < LiCl
(c) LiCl < BeCl2 < BCl3 < CCl4
(d) LiCl > BeCl2 > BCl3 > CCl4
Ans: (c)
8. Which statement is NOTcorrect?
(a) Asigma bond is weaker than a S-bond.
(b) Asigma bond is stronger than a S-bond.
(c) Adouble bond is stronger than a single bond.
(d) Adouble bond is shorter than a single bond.
Ans: (a)
9. Which one shows maximum hydrogen
bonding?
(a) H2O
(b) H2 Se
(c) H2 S
(d) HF.
Ans: (d)
10. Linear combination of two hybridized
orbitals belonging to two atoms and each having
one electron leads to a
(a) Sigma bond
(b) Double bond
(c) Co-ordinate covalent bond
(d) Pi bond.
Ans: (a)
11. Which one of the following formulae does
not correctly represent the bonding capacities of
the two atoms involved?
(a)
(b)
(c)
28
(d)
Ans: (d)
12. In compound X, all the bond angles are
exactly 28°109; X is
(a) Chloromethane
(b) Carbon tetrachloride
(c) Iodoform
(d) Chloroform.
Ans: (d)
13. Which of the following bonds will be most
polar?
(a) N– Cl
(b) O– F
(c) N– F
(d) N– N
Ans: (c)
14. Which one of the following has the shortest
carbon carbon bond length?
(a) Benzene
(b) Ethene
(c) Ethyne
(d) Ethane
Ans: (c)
15. Which structure is linear?
(a) SO2
(b) CO2
(c) CO3-2
(d) SO4-2
Ans: (b)
Chapterwise Previous year Qs
(b) NaF
(c) CsF
(d) RbF
Ans: (b)
19. Which one of the following is the correct
order of interactions?
(a) Covalent < hydrogen bonding < vander
Waals < dipole-dipole
(b) vander Waals < hydrogen bonding < dipole <
covalent
(c) vander Waals < dipole-dipole < hydrogen
bonding < covalent
(d) Dipole-dipole < vander Waals < hydrogen
bonding < covalent.
Ans: (b)
20. Strongest bond is in between
(a) CsF
(b) NaCl
(c) Both
(d) none of the above
Ans: (a)
21. Mark the incorrect statement in the
following
(a) The bond order in the species O2, O2 + and O2
– decreases as O2+ > O2> O2(b) The bond energy in a diatomic molecule
always increases when an electron is lost
(c) Electrons in antibonding M.O. contribute to
repulsion between two atoms.
(d) With increase in bond order, bond length
decreases and bond strength increases.
Ans: (b)
16. Strongest hydrogen bond is shown by
(a) Water
(b) Ammonia
(c) Hydrogen fluoride
(d) Hydrogen sulphide.
Ans: (c)
22. The weakest among the following types of
bonds is
(a) ionic
(b) covalent
(c) metallic
(d) H–bond.
Ans: (d)
17. Which of the following statements is not
correct?
(a) Double bond is shorter than a single bond
(b) Sigma bond is weaker than a S(pi) bond
(c) Double bond is stronger than a single bond
(d) Covalent bond is stronger than hydrogen
bond.
Ans: (b)
23. Which of the following does not have a
tetrahedral structure?
(a) BH– 4
(b) BH3
(c) BH+4
(d) H2O
Ans: (b)
18. Among the following which compound will
show the highest lattice energy?
(a) KF
24. Which of the following pairs will form the
most stable ionic bond?
(a) Na and Cl
29
Chapterwise Previous year Qs
(b) Mg and F
(c) Li and F
(d) Na and F
Ans: (b)
Ans: (d)
25. Among the following orbital bonds, the angle
is minimum between
(a) sp3 bonds
(b) px and py orbitals
(c) H– O– Hin water
(d) sp bonds.
Ans: (b)
26. Linus Pauling received the Nobel Prize for
his work on
(a) atomic structure
(b) photosynthesis
(c) chemical bonds
(d) thermodynamics
Ans: (c)
27. The boiling point of p-nitrophenol is higher
than that of o-nitrophenol because
(a) NO2 group at p-position behave in a different
way from that at o-position.
(b) intramolecular hydrogen bonding exists in pnitrophenol
(c) there is intermolecular hydrogen bonding in
p-nitrophenol
(d) p-nitrophenol has a higher molecular weight
than o-nitrophenol.
Ans: (c)
28. The distance between the two adjacent
carbon atoms is largest in
(a) benzene
(b) ethene
(c) butane
(d) ethyne
Ans: (c)
29. Which of
paramagnetic?
(a) O22(b) NO
(c) CO
(d) CN –
Ans: (b)
the
following
species
is
30. The BCl3 is a planar molecule whereas NCl 3
is pyramidal because
(a) B-Cl bond is more polar than N-Cl bond
(b) N-Cl bond is more covalent than B-Cl bond
(c) nitrogen atom is smaller than boron atom
(d) BCl3 has no lone pair but NCl 3 has a lone pair
of electrons
31. The correct order of the O–Obond length in
O2, H2O2 and O3 is
(a) O2>O3>H 2O2
(b) O3>H2O2>O2
(c) O2> H2O2> O3
(d) H2O2> O3> O2
Ans: (d)
32.
(a) 0
(b) 1
(c) 2
(d) 3
Ans: (d)
33.
(a)
(b)
(c)
(d)
Ans: (c)
34. Which of the following compounds has a - 3
centre bond?
(a) Diborane
(b) Carbon dioxide
(c) Boron trifluroide
(d) Ammonia
Ans: (a)
35. The low density of ice compared to water is
due to
(a) hydrogen-bonding interactions
(b) dipole-dipole interactions
(c) dipole-induced dipole interactions
(d) induced dipole-induced dipole interactions
Ans: (a)
36. The cylindrical shape of an alkyne is due to
the fact that it has
(a)
(b)
(c)
30
(d)
Ans: (d)
37. N 2 and O2 are converted into monocations,
N 2 +and O2 +respectively. Which of the following
statements is wrong?
(a) In N 2, the N—Nbond weakens
(b) In O2, the O—Obond order increases
(c) In O2, paramagnetism decreases
+
(d) N 2 becomes diamagnetic
Ans: (b)
Chapterwise Previous year Qs
Ans: (c)
42. Which of the following molecules is planar?
(a) SF 4
(b) XeF 4
(c) NF 3
(d) SiF 4
Ans: (b)
43.
38. The AsF 5 molecule is trigonal bipyramidal.
The hybrid orbitals used by the As atom for
bonding are
(a)
(b)
(c)
(d)
Ans: (c)
39. The number of anti-bonding electron pairs
in O2-2 molecular ion on the basis of molecular
orbital theory is, (Atomic number of Ois )8
(a) 5
(b) 2
(c) 3
(d) 4
Ans: (d)
(a) bonding is %100 ionic in both the molecules
(b) ABhas more ionic bond character than CD
(c) ABhas lesser ionic bond character than CD
(d) bonding is nearly covalent in both the
molecules
Ans: (c)
44. Which one of the following arrangements
represents the increasing bond orders of the
given species?
(a) NO+ < NO< NO– < O2 –
(b) O2 – < NO– < NO<NO+
(c) NO– < O2 – < NO< NO+
(d) NO< NO+ < O2 – < NO–
Ans: (b)
45. Which one of the following has the
pyramidal shape?
(a) CO32 –
(b) SO3
(c) BF 3
(d) PF 3
Ans: (d)
40. Among the following which one is not
paramagnetic? [Atomic numbers: Be = 4, Ne =
10, As = 33, Cl = ]17
(a) Cl–
(b) Be+
(c) Ne+ 2
(d) As+
Ans: (a)
41. In PO43– ion, the formal charge on each
oxygen atom and P—O bond order respectively
are
(a) –0.75, 0.6
(b) – 0.75, 1.0
(c) – 0.75, 1.25
(d) –3, 1.25
46. Which one of the following molecules will
form a linear polymeric structure due to
hydrogen bonding?
(a) NH3
(b) H2O
(c) HCl
(d) HF
Ans: (d)
47. Among the following the electron deficient
compound is:
(a) BCl3
(b) CCl4
(c) PCl5
(d) BeCl2
Ans: (a)
31
Chapterwise Previous year Qs
48. The relationship between the dissociation
energy of N 2 and N 2 +is:
(a) Dissociation energy of N 2 + > dissociation
energy of N 2
(b) Dissociation energy of N 2 = dissociation
+
energy of N 2
(c) Dissociation energy of N 2 > dissociation
energy of N 2 +
(d) Dissociation energy of N 2 can either be lower
or higher than the dissociation energy of N 2+
Ans: (c)
49. Cation and anion combines in a crystal to
form following type of compound.
(a) ionic
(b) metallic
(c) covalent
(d) dipole-dipole
Ans: (a)
50.
(d)
Ans: (a)
54.
(a) Electron density on Xwill increase and on
Hwill decrease
(b) In both electron density will decrease
(c) In both electron density will increase
(d) Electron density will decrease on Xand will
increase on H
Ans: (a)
55.
(a) NO3–
(b) SO32–
(c) BO33–
(d) CO32–
Ans: (b)
(a) NO2(b) NO3(c) 3 PO43(d) 2 CO32Ans: (c)
56. In NO3– ion number of bond pair and lone
pair of electrons on nitrogen atom respectively
are
(a) 2, 2
(b) 3, 1
(c) 1, 3
(d) 4, 0
Ans: (d)
51. In which of the following the bond angle is
57. Which of the following statements is not
maximum?
(a) NH3
(b) SCl2
(c) NH4 +
(d) PCl3
Ans: (c)
52. Which of
isostructural?
(a) NH3, BF 3
(b) PCl5, ICl5
(c) XeF 2, IF 2 –
(d) CO3 –2, SO3 –2
Ans: (c)
the
following
two
are
53. Main axis of a diatomic molecule is z,
molecular orbital p x and py overlap to form
which of the following orbital?
(a)
(b)
(c)
correct for sigma and pi-bonds formed between
two carbon atoms?
(a) Sigma-bond determines the direction
between carbon atoms but a pi-bond has no
primary effect in this regard
(b) Sigma-bond is stronger than a pi-bond
(c) Bond energies of sigma- and pi-bonds are of
the order of 264 kJ/mol and 347 kJ/mol,
respectively
(d) Free rotation of atoms about a sigma-bond is
allowed but not in case of a pi-bond
Ans: (c)
58. Among the following the pair in which the
two species are not isostructural is
(a)
(b)
(c)
(d)
Ans: (a)
32
59.
Chapterwise Previous year Qs
(d) BeCl2 < NaCl < LiCl
Ans: (c)
(a) three
(b) two
(c) six
(d) four
Ans: (a)
65. Which of the following molecules has
trigonal planar geometry?
(a) BF 3
(b) NH3
(c) PCl3
(d) IF 3
Ans: (a)
60. H2Ois dipolar, whereas BeF 2 is not. It is
because
(a) the electronegativity of F is greater than that
of O
(b) H2O involves hydrogen bonding whereas
BeF 2 is a discrete molecule
(c) H2O is linear and BeF 2 is angular
(d) H2O is angular and BeF 2 is linear
Ans: (d)
66. Which of the following would have a
permanent dipole moment?
(a) SiF 4
(b) SF 4
(c) XeF 4
(d) BF 3
Ans: (b)
61.
(a)
(b)
(c)
(d)
Ans: (a)
62. In BrF 3 molecule, the lone pairs occupy
equatorial positions to minimize
(a) lone pair - bond pair repulsion only
(b) bond pair - bond pair repulsion only
(c) lone pair - lone pair repulsion and lone pair bond pair repulsion
(d) lone pair - lone pair repulsion only
Ans: (c)
63. Which of the following is the electron
deficient molecule?
(a) C2H6
(b) B 2H6
(c) SiH 4
(d) PH3
Ans: (b)
64. The correct sequence of increasing covalent
character is represented by
(a) LiCl < NaCl < BeCl 2
(b) BeCl2 < LiCl < NaCl
(c) NaCl < LiCl < BeCl 2
67. Which of the following is not a correct
statement?
(a) The canonical structures have no real
existence
(b) Every AB 5 molecule does in fact have square
pyramidal structure
(c) Multiple bonds are always shorter than
corresponding single bonds
(d) The electron-deficient molecules can act as
Lewis acids
Ans: (b)
68. The number of unpaired electrons in a
paramagnetic diatomic molecule of an element
with atomic number 16 is
(a) 3
(b) 4
(c) 1
(d) 2
Ans: (d)
69. In which of the following molecules all the
bonds are not equal?
(a) BF 3
(b) AlF 3
(c) NF 3
(d) ClF 3
Ans: (d)
33
70. The electronegativity difference between
Nand Fis greater than that between Nand Hyet
the dipole moment of NH 31.5( D) is larger than
that of NF 30.2( D) . This is because
(a) in NH 3 the atomic dipole and bond dipole are
in the same direction whereas in NF 3 these are
in opposite directions
(b) in NH 3 as well as NF 3 the atomic dipole and
bond dipole are in opposite directions
(c) in NH 3 the atomic dipole and bond dipole are
in the opposite directions whereas in NF 3 these
are in the same direction
(d) in NH 3 as well as in NF 3 the atomic dipole
and bond dipole are in the same direction
Ans: (a)
71. Which of the following species has a linear
shape?
(a) SO2
(b) NO2+
(c) O3
(d) NO2–
Ans: (b)
Chapterwise Previous year Qs
(d) 2 sigma and 1 pi bonds
Ans: (d)
76. The correct order of increasing bond angles
in the following triatomic species is:
(a)
(b)
(c)
(d)
Ans: (b)
77. Four diatomic species are listed below in
different sequences. Which of these presents the
correct order of their increasing bond order?
(a)
(b)
(c)
(d)
Ans: (d)
78. What is the dominant intermolecular force
72. Which of the following is not isostructural
with SiCl4?
(a) SO42 –
(b) PO43 –
(c) NH4 +
(d) SCl4
Ans: (d)
or bond that must be overcome in converting
liquid CH 3OH to a gas?
(a) Dipole-dipole interaction
(b) Covalent bonds
(c) London dispersion force
(d) Hydrogen bonding
Ans: (d)
73. In which of the following pairs, the two
species are iso-structure?
(a) SO32 – and NO3 –
(b) BF 3 an NF 3
(c) BrO3 – and XeO3
(d) SF 4 and XeF 4
Ans: (c)
79.
74. The correct order of C–O bond length
among CO, CO32- , CO2 is
(a) CO< CO32 – < CO2
(b) CO32 – < CO2 < CO
(c) CO< CO2 < CO32 –
(d) CO2 < CO32 – < CO
Ans: (c)
75. The angular shape of ozone molecule (O 3)
consists of:
(a) 1 sigma and 2 pi bonds
(b) 2 sigma and 2 pi bonds
(c) 1 sigma and 1 pi bonds
(a) NH2- and H 2O
(b) NO2- and H 2O
(c) BF 3 and NO2(d) NO2- and NH 2Ans: (c)
80.
In which of the following pairs of
molecules/ ions, the central atoms have sp 2
hybridization?
(a) NO2- and NH 3
(b) BF 3 and NO2(c) NH2- and HO2
(d) BF 3 and NH 2Ans: (b)
81. In which one of the following species the
central atom has the type of hybridization which
34
Chapterwise Previous year Qs
is not the same as that present in the other
three?
(a) SF 4
(b) I 3(c) SbCl52–
(d) PCl5
Ans: (c)
86. Which one of the following pairs is
isostructural (i.e., having the same shape and
hybridization) ?
82. Some of the properties of the two species,
NO3- and H 3O+ are described below. Which one
of them is correct?
(a) Similar in hybridization for the central atom
with different structures.
(b) Dissimilar in hybridization for the central
atom with different structures.
(c) isostructural with same hybridization for the
central atom.
(d) Isostructural with different hybridization for
the central atom.
Ans: (b)
(c)
83. In which of the following molecules the
central atom does not have sp 3 hybridization?
(a) NH4+
(b) CH4
(c) SF 4
(d) BF 4–
Ans: (b)
84. Considering the state of hybridization of
carbon atoms, find out the molecule among the
following which is linear?
(a)
(b)
(c)
(d)
Ans: (b)
(a)
(b)
(d)
Ans: (d)
87. Bond order of 1.5 is shown by:
(a) O2+
(b) O2(c) O22(d) O2
Ans: (b)
88. Which of the following species contains
three bond pairs and one lone pair around the
central atom?
(a) H2O
(b) BF 3
(c) NH2(d) PCI 3
Ans: (a)
89. The pair of species with the same bond
order is:
(a) O22– , B 2
(b) O2+, NO+
(c) NO, CO
(d) N 2, O2
Ans: (a)
90. During change of O2 to O2- ion, the electron
adds on which one of the following orbitals?
85.
(a)
(b)
(c)
(d)
Ans: (a)
(a)
91. Four diatomic species are listed below.
Identify the correct order in which the bond
order is increasing in them:
(b)
(c)
(d)
Ans: (a)
(a)
(b)
(c)
(d)
35
Chapterwise Previous year Qs
Ans: (d)
92.
(a)
Which of the following is electron -
deficient?
(a) (SiH 3) 2
(b) (BH 3) 2
(c) PH3
(d) (CH 3) 2
Ans: (b)
(b)
(c)
(d)
Ans: (d)
99.
93.
(a)
(a) H2O
(b) SO2
(c) NO2
(d) CO2
Ans: (a)
(b)
(c)
(d)
Ans: (d)
1.
94. Which of the following is paramagnetic?
(a) O2–
(b) CN –
(c) NO+
(d) CO
Ans: (a)
95. XeF 2 is isostructural with:
(a) ICl2 –
(b) SbCl3
(c) BaCl2
(d) TeF 2
Ans: (a)
2.
3.
96. In which of the following pair both the
species have sp3 hybridization?
(a) H2 S, BF 3
(b) SiF 4, BeH 2
(c) NF 3, H 2O
(d) NF 3, BF 3
Ans: (c)
97. The pair of species that has the same bond
order in the following is:
(a) O2, B 2
(b) CO, NO+
(c) NO– , CN –
(d) O2, N 2
Ans: (b)
98. In which of the following ionisation
processes the bond energy increases and the
magnetic behaviour changes from paramagnetic
to diamagnetic?
4.
5.
6.
7.
36
Chapterwise Previous year Qs
16.
8.
17.
18.
9.
19.
10.
20.
11.
12.
21.
13.
22.
23.
14.
24.
15.
25.
37
Chapterwise Previous year Qs
26.
27.
28.
34.
29.
30.
35.
31.
36.
32.
33.
37.
38.
38
Chapterwise Previous year Qs
39.
40.
42.
41.
43.
39
Chapterwise Previous year Qs
46.
47.
48.
44.
49.
50.
51.
52.
45.
53.
54.
40
Chapterwise Previous year Qs
55.
59.
56.
60.
61.
57.
58.
62.
41
63.
Chapterwise Previous year Qs
68.
64.
69.
65.
66.
70.
67.
42
Chapterwise Previous year Qs
71.
72.
75.
73.
76.
74.
77.
78.
43
Chapterwise Previous year Qs
79.
85.
80.
86.
81.
87.
88.
82.
89.
83.
84.
44
Chapterwise Previous year Qs
93.
94.
90.
95.
91.
96.
97.
98.
92.
45
99.
Chapterwise Previous year Qs