CHEMICAL BONDING AND MOLECULAR STRUCTURE – 2

1) The state of hybridisation of S in is the same as that of
a) CO2
b) SO3
c)
d)

2) Which among the given molecules has a linear structure ?
a)
b)
c)
d)

3) In which of the following molecules doesn’t the central atom use a hybrid atom in its bonding?
a)
b)
c)
d)

4) The hybridisation of the central atom in is
a)
b)
c)
d)

5) The d- orbital involved in hybridisation is
a)
b)
c)
d)

6) Which orbital is used by the oxygen atom to form a sigma bond with another oxygen atom in the molecule ?
a) Pure p-orbital
b)
c)
d)

7) The maximum number of covalent bonds by which two atoms can be bonded to each other is
a) four
b) Two
c) Three
d) No fixed number

8) The geometrical arrangement and shape of are respectively
a) Trigonal bipyramidal geometry, Linear
b) Hexagonal geometry, linear shape
c) Triangular planar geometry, triangular shape
d) Tetrahedral geometry, pyramidal shape

9) Which of the following statements about the repulsion between bond pairs(bp) and lone pairs (lp) is correct?
a) lp-lp > lp-bp> bp-bp
b) lp- bp >lp- lp-> bp –bp
c) bp –bp >lp- bp> lp- lp
d) Any of these depending upon the type of molecule

10) The shape of a covalent molecule is
a) Triangular
b) T- shaped
c) Pyramidal
d) Any of the above depending upon the number of lone pairs of electrons on A

11) The correct order of the bond angles is
a)
b)
c)
d)

12) Which of the following accounts for the bond angle of around the O atom in the water molecule?
a) lp- bp repulsions
b) The low I. E. of oxygen
c) The high electron affinity of oxygen
d) The small size of the O and H atoms

13) In which of the following species is the angle around the central atom exactly equal to ?
a)
b)
c)
d) None of the above

14) Which of the following structures is expected to have three bond pairs and one lone pair?
a)
b)
c)
d)

15) Which out of the following structures is expected to have three bond pairs and one lone pair ?
a) Tetrahedral
b) Octahedral
c) Trigonal planar
d) Pyramidal

16) If the central atom in a certain molecule has two lone pairs and three bond pairs, the shape of the molecule could be
a) T- shaped
b) Triogonal planar
c) Trigonal bipyramidal
d) Distorted tetrahedral

17) Of the three molecules which have a tetrahedral structure?
a) all the three
b)
c)
d)

18) A molecule contains two , two bonds and one lone pair of electrons in the valence shell of X. The arrangement of the lone and bond pairs is arrangement of lone pair as well as bond pairs is
a) Square pyramidal
b) Linear
c) Trigonal planar
d) Unpredictable

19) The bond angle of is
a)
b)
c)
d)

20) Which of the following molecules has the largest bond angle?
a)
b)
c)
d)

21) Which of the following set contains species having the same angle around the central atom?
a)
b)
c)
d)

22) The bond angle around the O atom in ethanol is
a)
b)
c)
d)

23) The bond angle around the central atom is highest in
a)
b)
c)
d)

24) A pair of molecules having identical geometry are
a)
b)
c)
d)

25) The pair of species with a similar shape is
a)
b)
c)
d)

26) Which of the following has the smallest bond length?
a)
b)
c)
d)

27) Which of the following bonds is the strongest?
a) F –F
b) I – I
c) Cl – Cl
d) Br –Br

28) Which of the following bonds have lowest bond energy?
a) C –C
b) N –N
c) H –H
d) O –O

29) Which of the following compounds is non-polar?
a)
b)
c)
d)

30) Which of the following gaseous molecules is polar?
a)
b)
c)
d)

31) Which of the following molecules is polar ?
a)
b)
c)
d) All are polar

32) Which of the following molecules has a zero dipole moment?
a)
b)
c)
d)

33) Which of the following molecules has the highest dipole moment?
a)
b)
c)
d)

34) Which of the following molecules has non-zero dipole moment?
a)
b)
c)
d)

35) The molecule that does not posses a permanent dipole moment is
a)
b)
c)
d)

36) The dipole moment of is smaller than
a)
b)
c)
d)

37) Point out the false statement:
a) A molecule represents a more stable state as compared to individual atoms
b) Carbon tetrachloride is a non-polar molecule
c) Ionic compounds generally have low melting points and boiling points
d)

38) are both covalent compounds but is polar whereas is non-polar. This is because
a) the nitrogen atom is smaller than the boron atom
b) The N-F bond is more polar than the B-F bond
c)
d)

39) Which of the following about the molecule is not true?
a)
b) The molecule can act as a base
c) The substance shows an abnormally high boiling point in comparison to the hydrides of the other elements of the oxygen group.
d) The molecule has a bent shape

40) The molecular size of ICl and is approximately same, but the boiling point of ICI is about higher than that of . It is because
a) the ICI bond is stronger than the Br-Br bond
b) the IE of iodine is > the IE of Br
c) ICl is polar while bromine is non-polar
d) I has a larger size than Br

41) Which of the following hydrogen halides has a high percentage of ionic character?
a) HF
b) HCl
c) HBr
d) HI

42) Which of the following pairs of elements form a compound with the maximum ionic character?
a) Na, Cl
b) K, I
c) Cs, F
d) Ca, F

43) The correct order of decreasing polarity is
a)
b)
c)
d)

44) The correct order of increasing covalent character of the following is
a)
b)
c)
d)

45) The unit of dipole moment is a/an
a) Einstein
b) Debye
c) Dalton
d) Curie

46) One debye(D) which is the unit of polarity is equal to
a)
b)
c)
d)

47) If the electronegativity difference between two atoms A and B is 2.0, then the percentage of covalent character in the molecule is
a)
b)
c)
d)

48) The dipole moment of HCl is 1.03 D. If the H-Cl bond distance is what is the percentage of ionic character in the H-Cl bond?
a) 60%
b) 39%
c) 29%
d) 17%

49) Which of the following statements is not correct regarding bonding molecular orbitals?
a) Bonding molecular orbitals posses less energy than the atomic orbitals from which they are formed.
b) Bonding molecular orbitals have low electron densities between the two nuclei
c) Every electron in bonding molecular orbitals contributes to the attraction between atoms.
d) They are formed when the lobes of the combining atomic orbitals have the same sign.

50) Which of the following combinations is not allowed ( assume the z-z axis is the intermolecular axis)?
a) 2s and 2s
b)
c)
d)

51) Bond order is defined as
a) the difference in the number of electrons in the bonding MO and in the antibonding MO
b) Half of the value of (a)
c) the difference in the number of valence electrons of the two combining atoms
d) Half of the value of ( c )

52) For a stable molecule the value of the bond order should be
a) negative
b) positive
c) zero
d) No relationship of stability and bond order

53) Bond order is
a) Directly related to bond length
b) Inversely related to bond length
c) Inversely related to bond strength
d) Never fractional

54) Which of the following statements is incorrect?
a) He molecule does not exists because its bond order is zero
b)
c) Any two atomic orbitals can combine to form two molecular orbitals
d)

55) Which of the following statements is correct about molecule?
a) It has a bond order of 3
b) The number of unpaired electrons present in it is zero and hence it is diamagnetic
c)
d) All the above three statements are correct

56) The calculated bond order in the superoxide ion is
a) 2.5
b) 2
c) 1.5
d) 1

57) The bond order in the peroxide ion is
a) 2.5
b) 2
c) 1.5
d) 1

58) In which of the following diatomic molecules is the bond order of each molecule ?
a)
b)
c)
d)

59) The bond order in is the same as in
a)
b)
c)
d)

60) The bond lengths of are in the order
a)
b)
c)
d)

61) Which sequence correctly describes the relative bond strength of the oxygen molecule, the superoxide ion, the peroxide ion and the uni-positive oxygen molecule?
a)
b)
c)
d)

62) The bond energies in NO, follow the order
a)
b)
c)
d)

63) The number of unpaired electrons in is
a) 1
b) 2
c) 3
d) 0

64) Which of the following molecules or molecular ions have only one unpaired electron?
a)
b)
c)
d)

65) Which of the following molecules have unpaired electrons?
a)
b)
c)
d)

66) Which of the following theory provides a good explanation for the paramagnetic behavior of oxygen?
a) Resonance theory
b) VSEPR theory
c) Molecular Orbital theory
d) Valence bond theory

67) Which of the following species is paramagnetic?
a)
b)
c)
d)

68) Which of the following molecules /ions is paramagnetic and also has a bond order equal to 0.5?
a)
b)
c)
d)

69) In which set of molecules are all the species paramagnetic ?
a)
b)
c)
d)

70) Which of the following species is diamagnetic?
a)
b) NO
c)
d)

71) In the formation of a nitrogen molecule according to the MOT the outermost electron goes to
a)
b) sp-hybrid orbital
c)
d) 2p-orbital

72) In the molecular orbital diagram for ion the highest occupied orbital is
a) sigma MO orbital
b) Pi- MO orbital
c)
d)

73) The molecular orbital configuration of molecule is
a)
b)
c)
d)

74) How many bonds (bond order) does have?
a) 0
b) 1
c) 2
d) 3

75) In the formation of from NO , the electron is removed from
a) a sigma orbital
b) a pi- orbital
c)
d)

76) In the formation of from , the electron is removed from
a) a sigma orbital
b) a pi- orbital
c)
d)

77) If the molecule has zero dipole moment, the sigma bonding obitals used by M (atomic number <21) are
a) Pure p
b) Sp-hybrid
c)
d)

78) The shape of the sulphate ion is
a) square planar
b) tetrahedral
c) trigonal bipyramidal
d) hexagonal

79) Which one is paramagnetic and has the bond order ½?
a)
b)
c)
d)

80) Which of the following bonds will be non-polar?
a) N- H
b) C _H
c) F – F
d) O – H

81) Which of the following has a linear structure ?
a)
b)
c)
d)

82) The molecular orbital theory was given by
a) Mulliken
b) Moseley
c) Werner
d) Kossel

83) Which has a covalent bond?
a)
b)
c) NaH
d)

84) Which of the following is diamagnetic ?
a)
b)
c)
d)

85) The angle between the overlapping of one s-orbital and one p-orbital is
a)
b)
c)
d)

86) An equilateral-shaped molecule has
a) sp hybridisation
b)
c)
d)

87) Which of the following molecules is planar ?
a)
b)
c)
d) SiCl4

88) Which of the following molecules does not have a linear arrangement of atoms?
a)
b)
c)
d)

89) Which of the following does not apply to a metallic bond?
a) overlapping valence orbitals
b) mobile valence electrons
c) De-localized electrons
d) Highly directed bonds.

90) In which one of the following molecules can the central atom be said to adopt ?
a)
b)
c)
d)

91) In which of the following compounds does hydrogen bonding occur ?
a)
b)
c) HI
d)

92) has a net dipole moment while has zero dipole moment because
a)
b)
c) Fluorine has more electronegativity than oxygen
d) Beryllium has more electronegativity than oxygen.

93) The bond angle between H – O – H in ice is closest to
a)
b)
c)
d)

94) Which one has a pyramidal structure?
a)
b)
c)
d)

95) Which of the following has the shortest carbon-carbon bond length?
a)
b)
c)
d)

96) The predominant intermolecular forces in hydrogen fluoride is due to
a) dipole-induced dipole interactions
b) Dipole-dipole interactions
c) Hydrogen bond formation
d) Dispersion interaction

97) In co-ordinate valency
a) electrons are equally shared by the atoms
b) electrons of one atom are shared by two atoms
c) a hydrogen bond is formed
d) None of the above

98) The molecule/ion which has a pyramidal shape is
a)
b)
c)
d)

99) Which one of the following is paramagnetic ?
a)
b)
c)
d)

100) The molecule which has zero dipole moment is
a)
b)
c)
d)

Ans 1) b

Ans Desc 1) Hybridisation of S in SO2 and SO3 is sp2 whereas in SCl2 and it is sp3 while in SF4 it is sp3d .

Ans 2) a

Ans Desc 2)

(a) Total valence electrons in =5+2´ 6=16

Now

The hybridisation of N in
(b)The hybridisation in Sn in SnCl2=sp2
(c)
The hybridisation of S in SCl2=sp3
(d) Total electron in the valence shell of HOCL=1+6+7=14

Now,

Therefore hybridisation of Cl in HOCl is sp3

Thus has linear structure.

Ans 3) b

Ans Desc 3)

Total valence electrons in

Now . Therefore the hybridisation of Be in is .

In all the other molecules, the hybridisation of the central atom is sp3.

Ans 4) d

Ans Desc 4)

Total valence electrons in

Now .,

Therefore the sum of all quotients and all remainders =2+2+0=4.

The hybridisation of I in is sp3.

Ans 5) c

Ans Desc 5) is involved in sp3d hybridisation.

Ans 6) b

Ans Desc 6) Since the two O atoms in O2 are connected by a double bond (O=O) therefore hybridisation of O is sp2.

Ans 7) c

Ans Desc 7) The hybridisation which leads to the formation of maximum bonds between two atoms is sp. Therefore at the maximum three bonds can be formed between two atoms.

Ans 8) a

Ans Desc 8)

Total no of valence electrons in =7´ 3+1=22

Now and

Sum of all the quotients and final remainder=2+3+0=5

Therefore hybridization of I in =sp3d.

Thus has trigonal bipyramidal geometry with T-shape

Ans 9) a

Ans Desc 9)

Ans 10) d

Ans Desc 10)

Bond pair lone pair geometry
3 0 Triangular
3 1 Pyramidal
3 2 T-shaped

Ans 11) a

Ans Desc 11)

The bond angles depend upon (I) the electronegativity of the central atom and the number of lone pairs of electrons. The greater the electronegativity and the more the number of lone pairs, the smaller the angle. Since the electronegativities of N ( 93.0) and O (3.5) are close, but NH3 has one and H2O has two lone pairs of electrons, therefore the bond angle in NH 3(1070) is larger than in H2O(104.50). Similarly the electronegativities of P (2.1) and S (2.5) are close but PH3 has one while H2S has two lone pairs of electrons, therefore the bond angle in PH3(930) is a little more than that in H2S(92.20) . thus, the actual order is :

NH3>H2O >PH3 >H2S.

Ans 12) a

Ans Desc 12)

Ans 13) c

Ans Desc 13) In , hybridisation of N is sp3. Further there is no lone pair of electrons present in N, therefore ion has a regular geometry and regular tetrahedral bond angle of 1090 28.

Ans 14) d

Ans Desc 14) The N atom in NCl3 has one lone pair of electrons

Ans 15) d

Ans Desc 15) A pyramidal geometry has three bond pairs and one lone pair.

Ans 16) a

Ans Desc 16)

Ans 17) b

Ans Desc 17) Only in SiF4, the central atom ie; silicon does not have a lone pair and hence SiF4 has a tetrahedral structure.

Ans 18) c

Ans Desc 18) The valence shell of X has two bonds and one lone pair of electrons. Therefore, it has planar triangular geometry. It may be mentioned here that bond pairs involved in the formation of pi-bonds are not considered while deciding the geometry of the molecule.

Ans 19) c

Ans Desc 19) In a group, the bond angles decrease as the electronegativity of the central atom decreases. H2O >H2S>H2Se. Thus the bond angle in H2S is less than that of H2O but greater than that of H2Se. Thus H2S>H2Se<H2O is correct.

Ans 20) d

Ans Desc 20) CO2 has sp-hybridisation and hence has the largest bond angle of 1800. The bond angle in NH3 is 1070. In H2O it is 104.50 while in CH4, it is 1090 28

Ans 21) d

Ans Desc 21) The central; atom B has sp2 -hybridisation in BF4, BCl3 and BBr3. As a result, all have the same bond angle of 1200.

Ans 22) c

Ans Desc 22) The O atom in C2H5OH like in H2O is sp3 hybridised and hence the bond angle around O is approx. 1090.

Ans 23) b

Ans Desc 23)

The hybridisation of B in BBr3 is sp2, that of C in CS2 is sp, that of S in SO2 is sp2 while that of S in SF4 is sp3d. Hence CS2 has the maximum bond angle of 1800.

Ans 24) c

Ans Desc 24) CCl4 and CH4 have four bond pairs each and hence have tetrahedral geometry whereas BCl3 is planar but PCl3 is pyramidal; BF3is planar but NF3 is pyramidal. Both CHCl3 and CH3Cl have sp3 hybridisation but have little different geometries because CHCl3 has three polar C-Cl bonds while CH3 Cl has only one polar C-Cl bond.

Ans 25) a

Ans Desc 25) Both PCl3 and NH3 have pyramidal shape since both have sp3 hybridization and one lone pair of electrons. In contrast,all other pairs have different hybridization and hence different shapes. i.e., CF4 has sp3 while SF4 has sp3d hybridization; PbCl2 is ionic while CO2 has sp hybridization; PF5 has sp3d while IF5 has sp3d2 hybridization.

Ans 26) b

Ans Desc 26) N2 has the smallest bond length since it has a triple bond, while O2 has a double bond while Cl2 and HCl have single bonds.

Ans 27) c

Ans Desc 27) Bond length decreases as the size of the halogen increases. But due to inter-electronic repulsions between the small F- atoms, the F-F bond is weaker than Cl-Cl and Br-Br but is only slightly stronger than I-I. Thus the Cl-Cl bond is the strongest.

Ans 28) d

Ans Desc 28) Due to the inter-electronic repulsions between the small O atoms, the O-O bond is the weakest.

Ans 29) d

Ans Desc 29) All the molecules have polar C- Cl bonds. But in CCl4 due to regular tetrahedral geometry, the four dipole moments cancel each other. Hence CCl4 has zero dipole moment and thus is non-polar.

Ans 30) c

Ans Desc 30) CS2 is linear, BF3 is triangular planar and PbCl4 has regular tetrahedral geometry. Hence all these molecules have zero dipole moment. SnCl2, on the other hand, is a bent molecule with sp2 hybridization. It has therefore, a finite dipole moment and hence it is a polar molecule.

Ans 31) b

Ans Desc 31) In SO3, due to triangular planar shape and in SF6 due to regular octahedral shape all the dipole moments cancel out hence both have zero dipole moment. On the other hand SO2 has a bent shape and hence the two dipole moments do not cancel out.

Ans 32) d

Ans Desc 32) BF3 being triangular planar has zero dipole moment.

Ans 33) c

Ans Desc 33) NH3 being pyramidal has a finite dipole moment while all other molecules being symmetrical have zero dipole moment.

Ans 34) c

Ans Desc 34)

Ans 35) b

Ans Desc 35)

Ans 36) a

Ans Desc 36)

Ans 37) c

Ans Desc 37)

Ans 38) c

Ans Desc 38)

Ans 39) a

Ans Desc 39) The dipole moment of H2O is zero is a wrong statement

Ans 40) c

Ans Desc 40)

Ans 41) a

Ans Desc 41) The EN difference in HF(4-2.1=1.9) is highest and hence HF has high percentage of ionic character.

Ans 42) c

Ans Desc 42) Cs, F since the EN difference is highest ( 4-0.7 = 3.3 ).

Ans 43) b

Ans Desc 43) EN in HF=4- 2.1 =1.9 , in SO2=3.5-2.5=1.0, In H2O = 3.5 –2.1=1.4, In NH3 3.0-2.1=0.9. As the EN difference decreases, the percentage ionic character decreases accordingly, thus the correct order is : HF > H2O >SO2 > NH3.

Ans 44) b

Ans Desc 44)

EN difference in SiCl4=3.0-1.8=1.2

In AlCl3=3.0-1.5=1.5

In CaCl2=3.0-1.0=2.0 and

In KCl=3.0- 0.8=2.2

As EN difference increases the covalent character decreases. Thus, the correct increasing order of covalent character: KCl < CaCl2<AlCl3<SiCl4.

Ans 45) b

Ans Desc 45) Debye (D)

Ans 46) b

Ans Desc 46)

Ans 47) b

Ans Desc 47)

According to Hanary and Smith equation,

The % of ionic character = 16(xA-xB)+3.5 (xA-xB)2, where XA and xB are the electronegativities of the atoms A and B respectively.

Therefore % ionic character = 16(2)+ 3.5(2)2=32+14=46.

Ans 48) d

Ans Desc 48)

Dipole moment of HCl bond when 100 % ionic

By actual dipole moment=1.03D=

% ionic character =

Ans 49) b

Ans Desc 49) Bonding MOs have high electron density between the two nuclei.

Ans 50) d

Ans Desc 50) 2px and 2py combination is not allowed since their internuclear axes are perpendicular to each other.

Ans 51) b

Ans Desc 51) Bond order = ½(number of bonding electrons –no. of anti bonding electrons)

Ans 52) b

Ans Desc 52)

Ans 53) b

Ans Desc 53)

Ans 54) c

Ans Desc 54) Only atomic orbitals of comparable energy and proper orientation can combine to form two molecular orbital. As such statement (c ) is incorrect.

Ans 55) d

Ans Desc 55)

Ans 56) c

Ans Desc 56) B.O in superoxide ion =1/2(10-7)=1.5.

Ans 57) d

Ans Desc 57) B.O in peroxide ion

Ans 58) a

Ans Desc 58)

B.O. in N2 =1/2(10 – 4)=3.0

B.O. in N2+ =1/2(9 – 4)=2.5

B.O. in NO =1/2(10 – 5)=2.5

B.O. in O2+ =1/2(10 – 5)=2.5

B.O. in CN =1/2(10 – 4)=3

Thus option (a) is correct. Ie; N2+ , NO and O2+ all have the bond order of 2.5.

Ans 59) a

Ans Desc 59) and have the same bond order of 2.5.

Ans 60) d

Ans Desc 60)

Hint:Bond order in H2=

Bond order in ion =

B ond order in =

Although and ions have the same Bond order, has longer bond length than because of the presence of the one electron on the anti bonding orbital which repels the two H atoms from coming close.Further because of larger bond order, hydrogen molecule has the shortest bond length. Thus the actual order is: .

Ans 61) b

Ans Desc 61)

B O in O2 =1/2 (10-6)=2

B O in O 2=1/2(10-7)=1.5

B O in =1/2(10-5) =2.5

B O in =1/2(10-8)=1.0

As the bond order increases the bond strength increases accordingly Therefore, the correct order is:

.

Ans 62) a

Ans Desc 62)

B O in NO =1/2 (10-5)=2.5

B O in =1/2( 10-4)=3.0

B O in =1/2(10-6)=2.0

Since the bond energies are directly related to bond order, the correct order of increasing bond energies is:

Ans 63) b

Ans Desc 63) The number of unpaired electrons in O2=2.

Ans 64) a

Ans Desc 64) has one unpaired electron while O2 has two and H2 have zero unpaired electrons.

Ans 65) a

Ans Desc 65) Both O2 and B2 have two unpaired electrons each but O2 has these electrons in the antibonding MO while B2 has them in the bonding M O. In contrast N2 and Cl2 do not have any unpaired electrons.

Ans 66) c

Ans Desc 66)

Ans 67) a

Ans Desc 67) Only O2 has unpaired electrons and hence paramagnetic.

Ans 68) d

Ans Desc 68) O2 has two unpaired electrons and hence is paramagnetic but it has a B.O of 2. on the other hand, has one unpaired electron. It is not only paramagnetic but also has a B O of 0.5.

Ans 69) b

Ans Desc 69) B2 has two, O2 has two and NO has one unpaired electron and hence all these molecules are paramagnetic.

Ans 70) c

Ans Desc 70) The electronic configuration of is . Thus all the electrons are paired and hence NO+ is diamagnetic.

Ans 71) c

Ans Desc 71) The outermost electron in N2 goes to

Ans 72) c

Ans Desc 72)

Ans 73) a

Ans Desc 73)

Ans 74) b

Ans Desc 74) Bond order in B2=1/2 (6-4)=1.

Ans 75) d

Ans Desc 75) The formation of NO+ from NO, the electron is removed from the anti bonding

Ans 76) a

Ans Desc 76)

Ans 77) c

Ans Desc 77) Since the molecule (MX3) has zero dipole moment, therefore it must have triangular planar geometry and accordingly the hybridization of central metal atom (M) must be sp2.

Ans 78) b

Ans Desc 78) ion is tetrahedral since hybridisation of S is sp3.

Ans 79) d

Ans Desc 79) has one unpaired electron and hence is paramagnetic . Its bond order is ½. O2 is also paramagnetic since it has two unpaired electrons but its bond order is 2. N2 and F2 on the other hand, do not have unpaired electrons and hence are diamagnetic.

Ans 80) c

Ans Desc 80) Covalent bond between similar atoms are non-polar ie, F-F bond is non-polar.

Ans 81) c

Ans Desc 81) C2H2 has linear structure.

Ans 82) a

Ans Desc 82)

Ans 83) b

Ans Desc 83) In Na2S and NaH, sodium has +1 charge, in MgCl2 magnesium has +2 charge while in SnCl4, tin has a charge of +4. According to Fajan rule, the higher the charge on the cation, the greater is the polarizing power and hence the greater is the covalent character. Thus SnCl4has a covalent bond.

Ans 84) d

Ans Desc 84) All the electrons in are paired and hence it is diamagnetic. In contrast, O2 has two, and have one unpaired each and all those are paramagnetic.

Ans 85) a

Ans Desc 85) The overlap between s and p orbitals occurs along the inter-nuclear axis and hence the angle is 1800.

Ans 86) b

Ans Desc 86) Equilateral or triangular planar shape involves sp2 hybridization.

Ans 87) c

Ans Desc 87) Only C2H4 has sp2 hybridization and hence is planar while all the remaining molecules ( NH3,CH4, SiCl4)have sp3 hybridisation.

Ans 88) a

Ans Desc 88) Only H2S has sp3 hybridisation and hence has angular shape while C2H2, Be H2 and CO2 all involve sp-hybridisation and hence have linear arrangement of atoms.

Ans 89) d

Ans Desc 89) Metallic bonds have electrostatic attraction on all sides and hence do not have directional characteristics.

Ans 90) b

Ans Desc 90) BF3 involves sp2 hybridization.

Ans 91) d

Ans Desc 91) Only NH3 forms H-bonds.

Ans 92) b

Ans Desc 92) BeF2 is linear and hence had zero dipole moment while H2 O being a bent molecule, has a finite or non-zero dipole moment.

Ans 93) d

Ans Desc 93) Angle HOH in ice is 1050.

Ans 94) b

Ans Desc 94) NH3 has a pyramidal structure.

Ans 95) b

Ans Desc 95) C2H2 involves sp hybridization and since out of sp, sp2(C2 H4) and sp3 (C2 H6, C2 H5OH) sp- orbitals are the smallest, therefore carbon-carbon bond length is shortest in C2 H2.

Ans 96) c

Ans Desc 96) H-F forms strong H-bonds

Ans 97) b

Ans Desc 97) In coordinate bond formation, electrons of one atom are shared by two atoms.

Ans 98) a

Ans Desc 98) PCl3 has three bond pairs and one lone pair, therefore in accordance with VSEPR theory it has a pyramidal shape.

Ans 99) a

Ans Desc 99) Only has an odd number of electrons and hence is paramagnetic. All the remaining molecules/ions ie, CN(6+7+1=14), CO(6+8=14) and NO+ (6+8-1)=14) have an even number of electrons and hence are diamagnetic.

Ans 100) b

Ans Desc 100) BF3 is triangular planar and hence has zero dipole moment.

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