Multiple Choice Questions On Chemical bonding
1. The valency
of an element is ___________
(a) the
combining capacity of one atom of it
(b) the number
of bonds formed by its one atom
(c) the number
of hydrogen atoms that combine with one atom of it
(d) all the
above
Answer. (d)
2. The octet
rule is ___________
(a) the
tendency of atoms to have eight electrons in the outermost shell
(b) the
tendency of atoms to have eight pairs of electrons in the valency shell
(c) the
tendency of the molecule to have a total of eight electrons
(d) the
tendency of atoms to have eight non-bonding electrons
Answer. (a)
3. An ionic
bond is formed between ___________
(a) two metal
atoms
(b) two
non-metal atoms
(c) one metal
atom and one non-metal atom
(d) one metal
atom and one metalloid atom
Answer. (c)
4. Factors
governing the formation of an ionic bond are ___________
(a) low ionization
energy of metal and high electron affinity of non-metal atom
(b) high ionization
energy of metal and high electron affinity of non-metal atom
(c) low ionization
energy of metal atom and low electron affinity of non-metal atom
(d) high ionization
energy of metal and low electron affinity of non-metal atom
Answer. (a)
5. The lattice
energy is the amount of energy that ___________
(a) is released
when one cation combines with one anion
(b) is released
when one mole of cations combine with one mole of anions
(c) is released
when one mole of an ionic compound is formed from its cations and anions
(d) is absorbed
when one mole of an ionic compound is formed from its cation and anions
Answer. (c)
6. The most
favourable conditions for the formation of an ionic compound is ___________
(a) low charge
on ions, small cation and small anion
(b) high charge
on ions, large cation and large anion
(c) high charge
on ions, small cation and large anion
(d) low charge
on ions, large cation and small anion
Answer. (c)
7. Ionic
compounds are generally ___________
(a) solids
having large melting points and good conductors of electricity
(b) gases
having low melting points and poor conductors of electricity
(c) solids
having low melting points and good conductors of electricity
(d) solids
having high melting points and bad conductors of electricity
Answer. (a)
8. A covalent
bond involves ___________
(a) sharing of
electrons between a metal and a non-metal atom
(b) sharing of
electrons between two metal atoms
(c) sharing of
electrons between two atoms having similar electronegativity
(d) sharing of
electrons between two atoms having a large difference in electronegativity
Answer. (c)
9. The total
number of electron pairs in a nitrogen molecule is ___________
(a) 2
(b) 3
(c) 5
(d) 7
Answer. (d)
10. The
covalent compounds are soluble in ___________
(a) all acids
(b) all bases
(c) all
solvents
(d) non-polar
solvents
Answer. (d)
11. The
compounds which contain both ionic and covalent bonds are ___________
(a) CHCl3 and
CCl4
(b) KCl and
AlCl3
(c) KCN and
NaOH
(d) H2
and CH4
Answer. (c)
12. A
co-ordinate bond is formed by ___________
(a) complete
transfer of electrons
(b) sharing of
electrons contributed by both the atoms
(c) sharing of
electrons contributed by one atom only
(d) none of
these
Answer. (c)
13. The types
of bonds present in sulphuric acid molecules are ___________
(a) only
covalent
(b) ionic and
covalent
(c) co-ordinate
and covalent
(d)
co-ordinate, covalent and ionic
Answer. (d)
14. The common
feature among the species O3, SO42–, H3O+
and AlCl3 is that ___________
(a) they
contain only ionic bonds
(b) they
contain only covalent bonds
(c) they
contain co-ordinate bond
(d) they
contain covalent and ionic bonds
Answer. (c)
15. The species
CO, CN– and N2 are ___________
(a)
isoelectronic
(b) having
co-ordinate bond
(c) having low
bond energies
(d) having
polar bonds
Answer. (a)
16. The polarity of a covalent bond is due to ___________
(a) lesser
electronegativity difference between two atoms
(b) greater
electronegativity difference between two atoms
(c) lesser bond
energy
(d) greater
bond energy
Answer. (b)
17. A CO2
molecule contains two polar bonds but the net dipole moment is zero. It is
because ___________
(a) the
molecule has symmetrical linear geometry
(b) the
molecule is non-linear
(c) the
electronegativity difference between the two atoms is too large
(d) the electronegativity
difference between the two atoms is too small
Answer. (a)
18. Among BeF2,
BF3, NH3 and CCl4, the molecule with net
dipole moment is ___________
(a) BeF2
(b) BF3
(c) NH3
(d) CCl4
Answer. (c)
19. The common
feature among the molecules HF, H2O, HCl and NH3 is ___________
(a)
intramolecular H-bonding
(b)
intermolecular H-bonding
(c) that they
contain no polar bonds
(d) that their
dipole moment is zero
Answer. (b)
20. Methanol is
soluble in water due to
(a) covalent
bond nature
(b) ionic bond
nature
(c) hydrogen
bonding
(d) its
poisonous nature
Answer. (c)
21. Among H2O,
H2S, H2Se and H2Te, the substance with highest
boiling point is ___________
(a) H2O;
due to hydrogen bonding
(b) H2S;
due to large size of S atom
(c) H2Se;
due to large electronegativity difference
(d) H2Te;
due to largest size of Te atom
Answer. (a)
22. In ice
crystal, the H2O molecules are held together in a ___________
(a) planar
structure
(b) linear
structure
(c) tetrahedral
three dimensional structure
(d) none of
these
Answer. (c)
23. The density
of ice (solid) is lesser than that of water (liquid) because it has ___________
(a) open cage
like structure with no empty spaces
(b) open cage
like structure with large empty spaces
(c)
intermolecular H-bonding
(d)
intramolecular H-bonding
Answer. (b)
24. The density
of water is maximum at ___________
(a) 273 K
(b) 277 K
(c) 281 K
(d) 285 K
Answer. (b)
25. Among BeCl2,
CHCl3, CCl4 and PCl5, the octet rule is not
observed in ___________
(a) BeCl2
only
(b) PCl5
only
(c) BeCl2
and PCl5
(d) CHCl3
and CCl4
Answer. (c)
26. An example
of electron deficient compound among BF3, CF4, PF5
and SF6 is ___________
(a) BF3
(b) CF4
(c) PF5
(d) SF6
Answer. (a)
27. The
transition metals show variable valency because of ___________
(a) the
availability of vacant d-orbitals
(b) their
tendency to form complex ions
(c) their
ability to form coloured ions
(d) none of
these
Answer. (a)
28. The
electrical conductivity of metals is due to ___________
(a) mobile
protons is the nucleus
(b) mobile
nucleus in the nucleus
(c) mobile
electrons in outer vacant spaces
(d) none of
these
Answer. (c)
29. According
to VSEPR theory, ___________
(a) the lone
pairs only decide the structure of the molecule
(b) the bond
pairs only decide the structure of the molecule
(c) the lone
pairs and bond pairs both decide the structure of the molecule
(d) none of
these
Answer. (c)
30. In which of
the following, the central atom is surrounded by four electron pairs ___________
(a) H2O
(b) NH3
(c) CH4
(d) All
Answer. (d)
31. The
molecule among CCl4, PCl3, SF4 and NH3
that does not contain lone pairs of electrons around the central atom is ___________
(a) CCl4
(b) PCl3
(c) SF4
(d) NH3
Answer. (a)
32. Which of the following are isostructrual ___________
(a) SO2 and CO2
(b) SO2 and H2O
(c) BCl3 and CHCl3
(d) NH3 and CH4
Answer. (b)
33. The
molecular shapes of H2O, NH3 and CH4 are ___________
(a) similar
with 2, 1 and 0 lone pairs of electrons respectively
(b) similar
with 0, 1 and 2 lone pairs of electrons respectively
(c) different
with 0, 1 and 2 lone pairs of electrons respectively
(d) different
with 2, 1 and 0 lone pairs of electrons respectively
Answer. (d)
34. The
molecule of NH3 is ___________
(a) tetrahedral
with bond angle 109° 28′
(b) pyramidal
with bond angle 107° 20′
(c) trigonal
with bond angle 120°
(d) linear with
bond angle 180°
Answer. (b)
35. The NH4+
and SO42– ions have ___________
(a) tetrahedral
geometry
(b) triangular
geometry
(c) pyramidal
geometry
(d) square
planar geometry
Answer. (a)
36. Which is
incorrect?
(a) all
molecules with polar bonds have dipole moment
(b) all
molecules with polar bonds may or may not have dipole moment
(c) the greater
the difference in electronegativity between two atoms, greater is the polarity
(d) if the
electronegativity difference between two atoms is greater than 1.7, the bond
will be ionic
Answer. (a)
37. The
favourable conditions for the formation of H–bonding are ___________
(a) high
electronegativity and small size of the atom bonded to H–atom
(b) low
electronegativity and large size of the atom bonded to H–atom
(c) high
electronegativity and large size of the atom bonded to H–atom
(d) low
electronegativity and small size of the atom bonded to H–atom
Answer. (a)
38. The
strength of hydrogen bonding lies in between ___________
(a) covalent
and ionic bond
(b) metallic
and covalent bond
(c) van der
Waal’s and covalent bond
(d) metallic
and ionic bond
Answer. (d)
39. The bond
angles in a trigonal bipyramid molecules are ___________
(a) 90°
(b) 120°
(c) 109.5°
(d) 120°, 90°
Answer. (d)
40. CO2
has zero dipole moment whereas H2O has a dipole moment. It is
because ___________
(a) H2O
is linear while CO2 is a bent molecule
(b) of
intermolecular H–bonding in H2O molecules
(c) CO2 is
linear while H2O is a bent molecule
(d) CO2 is a
gas while H2O is a liquid at room temperature
Answer. (c)
41. Which of
the following does not obey the octet rule?
(a) PCl5
(b) H2O
(c) NH3
(d) CCl4
Answer. (a)
42. The total
number of electrons that take part in forming bonds in O2 is ___________
(a) 2
(b) 4
(c) 6
(d) 8
Answer. (d)
43. CO is
isoelectronic with ___________
(a) C2H2
(b) CN–
(c) O2+
(d) O2–
Answer. (b)
44. CO2
is isostructural with ___________
(a) H2O
(b) NO2
(c) H2S
(d) C2H2
Answer. (d)
45. In a bond
between two atoms X and Y, the shared electron pair does not lie in the centre.
The bond is ___________
(a) single bond
(b) non-polar bond
(c) polar bond
(d) co-ordinate
bond
Answer. (c)
46. The maximum
number of Hydrogen bonds formed by a water molecule is ___________
(a) 1
(b) 2
(c) 3
(d) 4
Answer. (b)
47. Out of the
following, intramolecular Hydrogen bonding exists in ___________
(a) water
(b) H2S
(c)
2-nitrophenol
(d)
4-nitrophenol
Answer. (c)
48. In a
compound, hydrogen bonding exists but there is no effect on physical properties
like m. pt., b. pt. etc. It shows the presence of ___________
(a) weak van
der Waal’s forces
(b)
intramolecular hydrogen bonding
(c)
intermolecular hydrogen bonding
(d) resonance
in the molecule
Answer. (b)
49. Which one
of the following is the most polar ___________
(a) H — F
(b) H — Cl
(c) H — Br
(d) H — I
Answer. (a)
Reference: Essentials of Physical Chemistry /Arun Bahl, B.S Bahl and G.D. Tuli / multicolour edition.
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