chemical bonding krr.pdf

Sri Chaitanya IIT–JEE Academy RAMAN BHAVAN-GUDAVALLI

CHEMISTRY -IIT QUESTIONS CHEMICAL BONDING

Sec :

Date : 11/11/11

Single answer type questions : 1. Which of the following molecules is adequately represented by a single Lewis structure? 1) O3 2) NOCl 3) SO2 4) N2O 2. Nodal plane in the pi bonds 1) a plane perpendicular to the molecular plane which contains C – C sigma bond 2) a plane perpendicular to the molecular plane and bisecting the C – C sigma bond 3) a plane parallel to the molecular plane 4) the molecular plane 3. Assuming the bond direction to be z-axis, which of the overlapping of atomic orbitals of two atoms A and B will result in bonding (I) s orbital of A and px orbital to B, (II) s orbital of A and pz orbital of B, (III) py orbital of A and pz orbital of B (IV) s orbitals of both A and B? 1) I and IV 2) I and II 3) III and IV 4) II and IV 4. Which is the correct sequence of decreasing O – O bond length in O2, H2O2 and O3? 5.

1) H2O2 > O3 > O2 2) O2 > O3 > H2O2 3) O2 > H2O2 > O3 4) O3 > H2O2 > O2 Which of the following statements is correct about the molecular structure of borontrifluoride?

I)

6.

II)

III)

IV)

1) All the structures contribute equally to the resonance hybrid 2) Structure I contributes maximum to the resonance hybrid 3) Structure II and IV contribute to greater extent to the resonance hybrid 4) The B–F bond has not been found to possess p character Increasing order of dipole moments is given by 1) CF4 < NH3 < NF3 < H2O 2) CF4 < NH3 < H2O < NF3 3) CF4 < NF3 < H2O < NH3

4) CF4 < NF3 < NH3 < H2O

7.

The common features among the species CN–, CO and NO+ is/are 1) isoelectronic and weak field ligands 2) bond order three and isoelectronic 3) bond order three and weak field ligands 4) bond order two and p-acceptors

8.

Amongst the species CO32- , NH 4+ , PH 3 , BCl3 , ClF3 , the isostructural pairs are 1) CO32- and ClF3

9.

2) NH 4+ and PH 3

3) CO32- and BCl3

4) PH3 and ClF3

The geometrical shapes of XeF5+ , XeF6 and XeF32- respectively are 1) trigonal bipyramidal, octahedral and square planar 2) square based pyramidal, distorted octahedral and octahedral 3) planar pentagonal, octahedral and square antiprismatic 4) square based pyramidal, distorted octahedral and square antiprismatic

10. Which of the following statements is/are true regarding ICl2- ion? 1) I-atom is sp3d hybridised 2) The three lone pairs occupy equitorial positions and two bond pairs the axial positions giving rise to linear shape

3) ICl acts as Lewis acid and Cl– ion acts as Lewis base 4) all of these 11. CrO2Cl2 has 1) tetragonal structure 2) distorted tetrahedral structure 3) square pyramidal structure 4) octahedral strucure 12. Consider the statements 0

I) Bond length in N2+ is 0.02 A greater than in N2 0

II) Bond length in NO+ is 0.09 A less than in NO III) O22- has a shorter bond length than O2 Then which of the following is correct? 1) I and III 2) II and III

3) I and II

4) I, III and III

13. In PO43- the formal charge on each oxygen atom and the P – O bond order are respectively 1) –0.75, 0.5 2) –0.75, 1.25 3) –0.75, 1.0 4) –3, 1.25 14.

PCl5 in the solid state exists as PCl4+ and PCl6- because 1) Solid PCl5 is a conductor

15.

16. 17.

18.

19.

20.

2) PCl4+ and PCl6- have stable, symmetrical structures unlike PCl5 that has an asymmetrical structure 3) Ion pairs are more stable than neutral molecules 4) Phosphorous belongs to V group in the periodic table Regarding hybridisation which is incorrect? 1) BF3, C2H4, C6H6 involves sp2 hybridisation 2) BeF3, C2H2, CO2 involves sp hybridisation 3) NH3, H2O, CCl4 involves sp3 hybridisation 4) CH4, C2H4, C2H2 involves sp2 hybridisation The correct order of arrangement of bond lengths is 1) F2 > N2 > Cl2 > O2 2) Cl2 > F2 > O2 > N2 3) O2 > Cl2 > N2 > F2 4) None The Cl – C – Cl angle in 1, 1, 2, 2 – tetra chloro ethene and tetrachloro methane respectively will be about 1) 109.50 and 900 2) 1200 and 109.50 3) 900 and 109.50 4) 109.50 and 1200 Dipole moment is exhibited by 1) 1, 4-dichlorobenzene 2) 1, 2-dichlorobenzene 3) trans 1, 2-dichloroethane 4) trans 1, 2-dichloro-2-butene Which one of the following about hydrogen bonding is false? 1) It alters some of the physical properties of the compound 2) Not all H-compounds can have hydrogen bonding 3) The H-atom in a hydrogen bonded pair of atoms is equidistant from the two atoms 4) Hydrogen bond is a weak bond Arrange the following in the decreasing order of hydrogen bonding CH4, CH3 – OH, CH3 – F, CH3 – NH2 1) CH3 – OH > CH3 – NH2 > CH3 – F > CH4 2) CH3 – OH > CH3 – F > CH3 – NH2 > CH4

21.

3) CH3 – F > CH3 – OH > CH3 – NH2 > CH4 4) CH4 > CH3 – F > CH3 – NH2 > CH3 – OH The melting point of 2-nitrophenol is lower than that of 4-nitrophenol and this is because of 1) Intramolecular hydrogen bonding in 2-nitrophenol 2) Intramolecular hydrogen bonding in 4-nitrophenol

22.

23.

24.

25.

3) Intermolecular hydrogen bonding in 2-nitrophenol 4) Hydrogen bonding has no relation to the melting point Which of the following is false? 1) The bond formed between two non metallic elements is covalent bond 2) The bond formed between two inert gas elements is Van der Waal’s bond 3) The bond formed between a metal and a non metal is electrovalent bond 4) The bond formed between two metallic elements is covalent bond A, B, C are three substances. A does not conduct electricity in the solid or liquid state. B conducts electricity both in the fused and solution states, while C conducts electricity only in the solution state. Which of the following statement is false regarding A , B and C? 1) A has polar covalent linkage 2) A has non polar covalent linkage 3) B is ionic nature 4) C has polar covalent linkage Molecular shapes of SF4, CF4 and XeF4 are 1) the same with 2, 0 and 1 lone pairs of electrons respectively 2) the same with 1, 1 and 1 lone pairs of electrons respectively 3) different with 0, 1 and 2 lone pairs of electrons respectively 4) different with 1, 0 and 2 lone pairs of electrons respectively SnCl4 is a covalent liquid because 1) Electron clouds of the Cl– ions are weakely polarised to envelop the cation 2) Electron clouds of the Cl– ions are strongly polarised to envelop the cation 3) Its molecules are attracted to one another by strong Van der Waal’s forces 4) Sn shows inert-pair effect

26.

27.

28.

The I 3- ion has 1) five equatorial lone pairs on the central I atom and two axial bonding pairs in a trigonal bipyramidal arrangement 2) five equatorial lone pairs on the central I atom and two axial bonding pairs in a pentagonal bipyramidal arrangement 3) three equatorial lone pairs on the central I atom and two axial bonding pairs in a trigonal bipyramidal arrangement 4) two equatorial lone pairs on the central I atom and three axial bonding pairs in a pentagonal bipyramidal arrangement The explanation of various intermolecular forces indicates 1) the unusual (anomalous) behaviour of H2O, NH3 and HF in terms of the relationship between molecular weight and boiling points is due to London forces 2) ion-dipole forces account for the solvation energy which plays an important role in the dissolving of ionic solids 3) for non polar molecules in the liquid state an important force acting as gravitational attraction 4) that London forces are due to very small permanent electric dipoles Amongst NO3- , AsO33- , CO32- , ClO3- , SO32- and BO33- the non planar species are 1) CO32- , SO32- and BO33-

2) AsO3- , ClO3- and SO32-

3) NO3- , CO32- and BO33-

4) SO32- , NO3- and BO33-

29.

Total number of electron pairs in PCl5, PCl4+ and PCl6- are respectively 1) 20, 16, 24 2) 24, 16, 20 3) 16, 20, 24 4) 24, 20, 16

30.

Which of the following statements is not correct for NO2, NO2+ and NO2- ? 1) NO2 is paramagnetic

2) NO2+ is linear, NO2- is bent, with bond angle slightly less than 1200 3) NO2+ ion has the shortest and strongest bonds 4) NO2- has longest and weakest bonds among these 31. 32.

33.

34.

35.

The formal charges on the three atoms in O3 molecule are 1) 0, 0, 0 2) 0, 0, –1 3) 0, 0, +1 4) 0, +1, –1 Which of the following statements about LiCl and NaCl is wrong? 1) LiCl has lower melting point that NaCl 2) LiCl dissolve more in organic solvents whereas NaCl does not 3) LiCl would ionize in water more than NaCl 4) Fused LiCl would be less conducting than fused NaCl The boiling points of methanol, water and dimethyl ether are respectively 650C, 1000C and 34.50C. Which of the following best explains these wide variations in b.p? 1) The molecular mass increases from water (18) to methanol (32) to diethyl ether (74) 2) The extent of H-bonding decreases from water to methanol while it is absent in ether 3) The density of water 1.00 g ml–1, methanol 0.7914 g ml–1 and that of diethl ether is 0.7137 gml–1 4) The number of H-atoms per molecule increases from water to methanol to ether In one of the following molecules, the state of hybridization of the central atom is not the same as in the others 1) B in BF3 2) O in H3O+ 3) N in NH3 4) P in PCl3 The correct order of the bound angles is 1) NH3 > H2O > PH3 > H2S 2) NH3 > PH3 > H2O > H2S 3) NH3 > H2S > PH3 > H2O

36.

37.

38.

39.

4) PH3 > H2S > NH3 > H2O

A diatomic molecule has dipolemoment of 1.2 D. If its bond distance is 1.0A0. What fraction of electric charge ‘e’ exists on each atom? 1) 12% of e 2) 18% of e 3) 25% of e 4) 30% of e Which of the following statements is not correct? 1) In CHCl3 molecule both dipole forces as well as dispersion forces exist 2) In H2O molecule both hydrogen bonds as well as dispersion forces are present 3) In CCl4 only dispersive force exist 4) In salicyladehyde both hydrogen bonds as well as dispersion forces are present In solid NH3, each NH3 molecule has 6 other NH3 molecules as nearest neighbours. DH of sublimation of NH3 at the melting point is 30.8 kJ/mole and the estimated DH of sublimation in the absence of hydrogen bonding is 14.4 kJ per mole. The strength of H-bond in solid NH3 is 1) 5.5 kJ/mole 2) 16.4 kJ/mole 3) 2.7 kJ/mole 4) –8.7 kJ/mole Consider the species NO3- , NO2+ and NO2- pick up the correct statement 1) The hybrid state of N in all the species is same 2) The shapes of both NO2+ and NO2- is bent while NO3- is planar 3) The hybrid state of N in NO3- , NO2- is same

40.

4) The hybrid state of N in NO2+ is sp Calcium carbide gets hydralised to form acetylene gas I) Hybrid stte of C does not change

41.

42.

43.

44. 45.

46.

47.

48.

II) Bonding between the carbon atoms does not change III) Boiling point of carbon compound does not change 1) I and II are correct 2) Only II is correct 3) I and III are correct 4) II and III are correct Which of the following statement is correct? 1) Non-bonding orbitals have the same energy as the bonding molecular orbitals 2) Antibonding orbitals have higher energies than highest energy atomic orbitals from which they are formed 3) Bonding orbitals have higher energies than the antibonding molecular orbitals 4) All are correct The bond order in peroxide ion and fluorine molecule is equal 1) these are iso electronic 2) their bond energies are nearly equal 3) their bond lengths are nealry equal 4) all of these Which N2 changes to N2+ , the N – N bond distance ............. and O2 changes to O2+ , the O – O bond distance ........ 1) increases, decreases 2) decreases, increases 3) increases in both cases 4) decrease in both cases In the electronic structure of H2SO4, the total number of unshared electron is : 1) 20 2) 16 3) 12 4) 8 A molecule may be represented by three structures having energies E1, E2 and E3, respectively. The energies of these structures follow the order E3 < E2 < E1, respectively. If the experimental bond energy of the molecule is E0, the resonance energy is : 1) (E1 + E2 + E3) – E0 2) E0 – E3 3) E0 – E1 4) E0 – E2 The hybridization of the central atom will change when : 1) CH3 combines with H+ 2) H3BO3 combines with OH– 3) NH3 forms NH 2Which has maximum dipole moment?

4) H2O combines with H+

1)

3)

2)

4)

Select pair of compounds in which both have different hybridization but have same molecular geometry 2) ICl2Q . BeCl2 3) BCl3, PCl3 4) PCl3, NCl3 The correct order of increasing s-character (in percentage) in the hybrid orbitals of following molecules/ions is : 1) BF3, BrF3

49.

I) CO32II) XeF4 III) I 3IV) NCl3 V) BeCl2 1) I < III < IV < I < V 2) II < IV < III < V < I 3) III < II < I < V < IV 4) II < IV < III < I < V 50.

N2 and O2 are converted to monocations N 2+ and O2+ respectively, which is wrong statement : 1) In N2+ , the N – N bond weakens

2) In O2+ , the O – O bond order increases

3) In O2+ , the paramagnetism decreases

4) N2+ becomes diamagnetic

51.

52.

Among the following compounds, which has the maximum number of sp-hybridized C atoms ? 1) (CN )2

2) CH = C = CH - CN

3) HC º C - CH 2CH 2 = C = C = CH 2

4) HC º C - CN

Phosphorus shows a maximum covalency of 1) five

53.

2) seven

3) six

4) three

Which of following statements are not correct ? 1) Hybrization is the maxing of atomic orbitals. 2) sp2-hybrid orbitals are formed from two p-atoms orbitals and one s-atomic orbital. 3) dsp 2 -hybrid orbitals are all at 900 to one another.. 4) d2sp3-hybrid orbitals are directed towards the corners of a regular octahedron

54.

Which of the following has a pyramidal shape ? 1) PCl3

55.

2) ( H 2 N )2 CO

3) HCHO

4) CH 3CHO

2) sp3 - sp3

3) sp - sp 2

4) sp 2 - sp 2

Which of the following has been arranged in increasing order of size of the hybrid orbitals ? 1) sp < sp 2 < sp3

58.

4) NO3-

The hybridization of carbon involved in the C-C single bond in the molecule CH º C - CH = CH 2 is. 1) sp3 - sp 2

57.

3) CO3-2

The compound in which carbon uses its sp3-hybrid orbitals for bond formation is. 1) HCO2 H

56.

2) SO3

2) sp3 < sp 2 < sp

3) sp 2 < sp3 < sp

4) sp 2 < sp < sp3

The shapes of PCl4+ , PCl4- and AsCl5 are respectively 1) square planar, tetrahedral and see-saw 2) tetrahedral, see-saw and trigonal bipyramidal 3) tetrahedral ,square planar and pentagonal bipyramidal. 4) trigonal bipyramidal, tetrahedral and square pyramidal

59.

CO2 is not isostructural with 1) HgCl2

2) SnCl2

3) C2 H 2

4) ZnCl2

60.

In the context of carbon, which of the following is arranged in the correct order of electronegativity. 1) sp < sp 2 > sp3

61.

62.

63.

- hybridization

2) sp3d

3) sp 3d xy - hybridization

4) sp 3 - d yz - hybridizaton

x 2- y

2

When 2s-2s, 2p-2p ans 2p-2s orbitals overlap, the bond strength decreases in the order. 1) p - p > s - s > p - s

2) p - p > p - s > s - s

3) s - s > p - p > p - s

4) s - s > p - s > p - p

Which of the following pairs are isostructural ? 2) NH 4+ and NH 3

3) SO42- and BF4-

4) NH 2- and BeF2

The shape of XeOF4 is. 2) square antiprismatic 3) distorted octahedral 4) pentagonal bipyramidal

The N - O - N bond angle is maximum in 1) NO2+

66.

4) sp3 < sp > sp 2

3 1) sp d z 2- hybridization

1) square pyramidal 65.

3) sp 2 < sp > sp3

PCl5 undergoes

1) CH 3- and CH 3+ 64.

2) sp3 < sp 2 > sp

2) NO2

3) NO2-

4) N 2O3

The shapes of XeF6 , XeF5- and XeF82- are 1) octahedral, trigonal bipyramidal and square planar 2) square pyramidal, pentagonal bipyramidal and octahedral 3) square planar, planar pentagonal and square antiprismatic 4) see-saw, T-shaped and square pyramidal

67.

The I3- ion has 1) five equatorial lone pairs on the central I atom and two axial bonding pairs in a trigonal bipyramidal arrangement 2) five equatorial lone pairs on the central I atom and two axial bonding pairs in a pentagonal bipyramidal arrangement 3) three equatorial lone pairs on the centre I atom and two axial bonding pairs in a trigonal bipyramidal arrangement 4) two equatorial lone pairs on the centre I atom and three axial bonding pairs in a trigonal bipyramidal arrangement

68.

The most likely arrangement of atoms in S2Cl2 is.

1) S - S - Cl - Cl 69.

2) S - Cl - S - Cl

3) S - Cl - Cl - S

4) Cl - S - S - Cl

Assuming the bond direction to be z-axis, which of the overlapping of atomic orbitals of two atoms A and B will result in bonding (I)s orbital of A and px orbital of B, (II) s orbital of A and pz orbital of B, (III) p y orbital of A and pz orbital of B (IV) s orbitals of both A and B ? 1) I and IV

70.

71.

72.

2) I and II

3) III and IV

4) II and IV

Which of the following molecules have unequal bond lengths ? 1) NF3 2) SF4 3) SF6 4) PF5 Which of the following sets of characteristics leads to the increase in solubility of ionic substances? 1) High dipole moment, strong attraction by an ion and large solvation energy 2) Low dipole moment, weak attraction by an ion and high solvation energy 3) High dipole moment, strong attraction by an ion and low solvation energy 4) High dipole moment, weak attraction by between ion and large solvation energy The explanation of various intermolecular forces indicates 1) the unusual (anomalous) behaviour of H2O, NH3 and HF in terms of the relationship between molecular weight and boiling points is due to London forces 2) ion-dipole forces account for the solvation energy which plays an important role in the dissolving of ionic solids 3) for non polar molecules in the liquid state an important force acting as gravitational attraction 4) that London forces are due to very small permanent electric dipoles 3) A+ and X– ions are approximately of the same size 4) A+ and X– ions are larger

73.

Which of the following have undistorted octahedral structures? b) PF6c) SiF624) XeF6 Select the correct answer using the codes given below : 1) b, c and d 2) a, c and d 3) a, b and c 4) a, b and d Sulphur reacts with chlorine in 1:2 ratio and forms X. Hydrolysis of X gives sulphur compound Y. What is the hybridization state of central atom in the anion of Y? 1) sp3 2) sp 3) sp2 4) sp2d a) SF6

74.

75.

In IC l -4 , the shape is square planar. The number of bond pair-lone pair repulsion at 90° are: 1) 6

76.

77.

79.

3) 12

4) 4

Arrange the following in order of decreasing N - O bond length : NO2+ , NO2- , NO31) NO3- > NO2+ > NO22) NO3- > NO2- > NO2+ 3) NO2+ > NO3- > NO24) NO2- > NO3- > NO2+ The correct order of increasing s-character (in percentage) in the hybrid orbitals of following molecules/ ions is: (I) CO32-

78.

2) 8

(II) XeF4

(III) I3-

(IV) NCl3

(V) BeCl2

1) II < III < IV < I < V 2) II < IV < III < V < I 3) III < II < I < V < IV 4) II < IV < III < I < V A molecule XY2 contains two s, two p-bonds and one lone pair of electron in the valence shell of X. The arrangement of lone pair as well as bond pairs is : 1) square pyramidal 2) linear 3) trigonal planar 4) unpredictable Nodal planes of p-bond(s) in CH2 = C = C = CH2 are located in :

1) all are in molecular plane 2) two in molecular plane and one in a plane perpendicular to molecular plane which contains C – C s-bonds 3) one in molecular plane and two in plane perpendicular to molecular plane which contains C – C s-bonds 4) two in molecular plane and one in a plane perpendicular to molecular plane which bisects C – C s-bonds at right angle 80. Which of the following molecules is adequately represented by a single Lewis structure? 1) O3 2) NOCl 3) SO2 4) N2O 81. Assuming the bond direction to be z-axis, which of the overlapping of atomic orbitals of two atoms A and B will result in bonding (I) s orbital of A and px orbital to B, (II) s orbital of A and pz orbital of B, (III) py orbital of A and pz orbital of B (IV) s orbitals of both A and B? 1) I and IV 2) I and II 3) III and IV 4) II and IV 82. Increasing order of dipole moments is given by 1) CF4 < NH3 < NF3 < H2O 2) CF4 < NH3 < H2O < NF3 3) CF4 < NF3 < H2O < NH3 83. Consider the statements

4) CF4 < NF3 < NH3 < H2O 0

I) Bond length in N2+ is 0.02 A greater than in N2 0

II) Bond length in NO+ is 0.09 A less than in NO III) O22- has a shorter bond length than O2 Then which of the following is correct? 1) I and III 2) II and III 3) I and II 4) I, III and III 84. Two moles of iron and two moles of chlorine react to produce 1) 1 mole of iron (III) chloride 2) 1.336 mole of iron (III) chloride 3) Two moles of iron (II) chloride 4) 1.5 mole of iron (III) chloride 85. The hybridization of the central atom will change when : 1) CH3 combines with H+ 2) H3BO3 combines with OH– 86.

3) NH3 forms NH 24) H2O combines with H+ Select pair of compounds in which both have different hybridization but have same molecular geometry 2) ICl2Q . BeCl2 3) BCl3, PCl3 4) PCl3, NCl3 The correct order of increasing s-character (in percentage) in the hybrid orbitals of following molecules/ions is : 1) BF3, BrF3

87.

88.

I) CO32II) XeF4 III) I 3IV) NCl3 V) BeCl2 1) I < III < IV < I < V 2) II < IV < III < V < I 3) III < II < I < V < IV 4) II < IV < III < I < V Between the molecules FNO and FNO2 one has dipolemoment of m = 1.81 D and the other has m = 0.47 D on the basis of VSEPR considerations assign the shapes and dipolemoments to the two molecules 1) FNO is angular with 0.47 D dipolemoment while FNO2 is pyramidal with dipolemoment 1.81 D 2) FNO is linear with 1.81 D dipolemoment while FNO2 is planar triangular dipolemoment 0.47 D 3) FNO is angular with 1.81 D dipolemoment while FNO2 is planar trigonal shape with 0.47 D dipolemoment 4) FNO is angular with 1.81 D while FNO2 is pyramidal with dipolemoment 0.47 D

89.

90.

91. 92.

When two compounds ACl3 and DCl3 of two elements A and D are mixed together a compound ADCl6 is formed. Structural analysis showed that ADCl6 is an ionic compound with bent triatomic cation. Given that DCl3 is trigonal planar and ACl3 is trigonal pyramidal predict the shape of anion. If the anion has a distorted tetrahedral shape what would be the shape of the cation 1) Tetrahedral, linear 2) Square pyramidal planar triangular 3) Distorted tetrahedral regular tetrahedral 4) Pyramidal tetrahedral In which of the following pair select the pair with largest bond angle difference a) NH3 and PH3 b) CF2 and DF2 c) PF4+ and PF4d) ClF3 and BF3 1) a 2) b 3) c 4) d Which of the following is an example of a planar molecule having a net dipolemoment 1) NH3 2) ClF3 3) XeO3 4) SO3 The bond angle of H2Se is best discribed as being 1) Between 1090 and 1200

93. 94.

95.

96.

97.

98.

99.

2) Greater than 1200

3) Less than that in H2S but not less than 900 4) Less than 900 The bond dissociation energy will increase in the order of 1) N2 < O2 < F2 < Cl2 2) F2 < O2 < Cl2 < N2 3) F2 < Cl2 < O2 < N2 4) Cl2 < F2 < O2 < N2 In molecules of the type AX2Ln (where L represents lone pairs ‘n’ its number then exists a bond between elements A and X. Then XAX angle 1) Always decreases if ‘n’ increases 2) Always increases if ‘n’ increases 3) Will be maximum for n = 4 4) Will always be less than 1800 if n = 0 Identify the correct statements : I) N3 is linear II) ClF3 has a dipolemoment III) SF4 has distorted tetrahedral (see - saw shape) IV) XeF4 is tetrahedral in shape 1) I, II, III and IV are correct 2) Only I, II and III are correct 3) Only I and II are correct 4) Only III and IV are correct Delocalisation of electrons may be expected in the species of formula I) N2H4 II) NO3– III) HNO3 IV) NH4+ 1) I, II and III only correct 2) I and III only correct 3) II and IV only correct 4) II and III only correct Which of the following possess two lone pair of electrons on the central atom and square planar in shape? I) SF4 II) XeO4 III) XeF4 4) ICl4– 1) I, II and III only correct 2) II and IV only correct 3) I and III only correct 4) III and IV only correct Which of the following molecules have a dative p bond I) P4O10 II) (SiH3)3 N III) P4O6 IV) N2O3 1) I, II and III only correct 2) II and IV only correct 3) I and III only correct 4) I and II only correct The hybridization of the central atom will change when : 1) CH3 combines with H+ 2) H3BO3 combines with OH–

3) NH3 forms NH 24) H2O combines with H+ 100. Select pair of compounds in which both have different hybridization but have same molecular geometry 1) BF3, BrF3

2) ICl2Q . BeCl2

3) BCl3, PCl3

4) PCl3, NCl3

101. The correct order of increasing s-character (in percentage) in the hybrid orbitals of following molecules/ions is : I) CO32II) XeF4 III) I 3IV) NCl3 V) BeCl2 1) I < III < IV < I < V 2) II < IV < III < V < I 3) III < II < I < V < IV 4) II < IV < III < I < V 102. Which of the following is correct order of angle between two fluorine atoms linked to central atom in the given molecules I) F2C = 0 II) N º SF3 III) F4S = 0 IV) F5I = 0 1) I > II > III > IV 2) I > III > II > IV 3) II > III > I > IV 4) III > IV > I > II 103. Arrange the following in the increasing order of their bond angles I) NH3 II) N(CH3)3 III) N(SiH3)3 IV) NF3 1) I > II > III > IV 2) II > I > IV > III 3) II > III > I > IV 4) III > II > I > IV 104. The electronic configuration of B2 molecule is different from the electronic configuration of F2 molecule is due to mixing of a) s1s & s 2 s orbitals b) s 2 s & s 2 p orbitals c) s* 2s & s 2 p orbitals d) s* 2 s & s* 2 p orbitals 105. Which of the following is correct? 1) The number of electrons present in the valence shell in SF6 is 12. 2) The rates of ionic compounds are very slow 3) According to VSEPR, SnCl2 is linear molecule 4) The correct order of ability to form ionic compounds among Na+, Mg2+ and Al3+ is Al3+ > Mg2+ > Na+ 106. Select pair of compounds in which both have different hybridization but have same molecular geometry : 1) BF3, BrF3 2) 3) BCl3, PCl3 4) PCl3, NCl3 107. Solid oxygen has a pale blue colour which is attributed to A) Electronic transition from the singlet ground state to the triplet ground state B) Electronic transitions from antibonding p* molecular orbitals (triplet state) to bonding s2Pz (doublet) molecular orbitals C) Electronic transitions from the antibonding p* molecular orbitals (triplet state) to excited antibonding s*2Pz molecular orbital (singlet state) D) Electronic transitions from the triplet ground state to the singlet ground state 108. Which of the following sets of characteristics leads to the increase in solubility of ionic substances? a) High dipole moment, strong attraction by an ion and large solvation energy b) Low dipole moment, weak attraction by an ion and high solvation energy c) High dipole moment, strong attraction by an ion and low solvation energy d) High dipole moment, weak attraction by an ion and large solvation energy 109. A sigma bond may be formed by the overlap of 2 atomic orbitals of atoms A and B. If the bond is formed along the X–axis which of the following overlaps is acceptable 1) s-orbital of A and pz orbital of B 2) px orbital of A and py orbital of B 3) px orbital of A and pz orbital of B 4) px orbital of A and s – orbital of B 110. The way of writing the Lewis structure of the cyanate ion OCN– places one double bond between the carbon atom and the oxygen atom and another double bond between the carbon atom and nitrogen atom. What are the formal charges on the oxygen, carbon and nitrogen atoms, respectively for those structure 1) 0, 0, –1 2) –1, 0, 0 3) –1, +1, –1 4) –2, 1, 0

111. Which of the following is correct? 1) The number of electrons present in the valence shell in SF6 is 12. 2) The rates of ionic compounds are very slow 3) According to VSEPR, SnCl2 is linear molecule 4) The correct order of ability to form ionic compounds among Na+, Mg2+ and Al3+ is Al3+ > Mg2+ > Na+ 112. Which of the following is not a correct statement? 1) Every AB5 molecule does in fact have square pyramidal structure 2) Multiple bonds are always shorter than corresponding single bonds 3) The electron deficient molecules act as Lewis acids 4) The canonical structures have no real existence 113. Most stable moecules 1) have paired electrons and are dia magnetic 2) have unpaired electrons and are para magnetic 3) have paired electrons and are ferrimagnetic 4) have unpaired electrons and are ferromagnetic + 114. The correct order of Bond angle of NO2 , NO2 and NO2– is 1) NO2+ < NO2 < NO2– 2) NO2+ = NO2– < NO2 3) NO2+ > NO2 > NO2– 4) NO2+ > NO2 < NO2– 115. The tetrahedral geometry of methane instead of square planar structure is supported by a) Its dipole moment value b) Its monochlorination c) Its dichlorination d) Its trichlorination 116. Which of the following is the correct order of the strength of hydrogen bonding in the given compound a) HF < NH3 b) H2O > H2O2 c) H2O2 > H2O d) NH3 > H2O 117. Which of the following statements is incorrect 1) A sigma bond has no free rotation around its axis 2) Two p-orbitals always overlap laterally 3) There can be more than one sigma bond between two atoms 4) All of these 118. Which of the following conditions favours two formation of an ionic bond 1) Cation with low positive charge 2) Cation with large radius 3) Anon with large size 4) All of these 119. The molecule MLx is planar with six pairs of electrons around ‘M’ in the valence shell. The value of ‘x’ is a) 6 b) 2 c) 4 d) 3 120. Mark the incorrect statement in the following : a) The bond order in the species O2 , O2+ and O2- decreases as O2+ > O2 > O2b) 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 121. Which of the following molecules has(have) a SP2 hybridised atom? a) CBr4 b) CH2=CH2 c) BF3 a) B&C

122.

b) C&D

c) B,C&D

d) SO2 d) B&D

Which of the following about SF4, SOF4 and COF2 molecules is correct 1) Equatorial FSF bond angle in SOF4 will be less than in SF4 molecule 2) Hybridisation state of sulphur in SF4 and SOF4 molecules will be different 3) The bond angle FCO will be < 1200 in molecule OCF2 4) The axial FSF bond angle in SF4 is dissociation energy of N 2+ 3) Dissociation energy of N2 < dissociation energy of N 2+ 4) Dissociation energy of N2 can either be lower or higher than the dissociation energy of N 2+ 134. Which of the following set of species have planar structures? 1) I 3- , CH 3 , ClO3- , SiF62-

2) I 3+ , ICl4- , Al2Cl6 , TeCl4

3) SCl2 , N 2O5 , SF4 , XeOF4 4) I 2Cl6 , XeF2 , BrF4- , XeF5135. The boiling point of p-nitrophenol is higher than that of o-nitrophenol because : 1) p-nitrophenol has inter-molecular hydrogen bonding while o-nitrophenol has intrahydrogen bonding 2) p-nitrophenol has intramolecular hydrogen bonding while o-nitrophenol has inter-molecular

hydrogen bonding 3) –NO2 group at p-position behaves in a different way than that of o-position 4) Hydrogen bonding exists in p-nitrophenol but no hydrogen bonding is present in o-nitrophenol 136. In which species is the electron pair geometry is the same as the molecular geometry 1) BeF2 2) PF3 3) SF4 4) IF5 137. In an H 2+ ion 1) One electron is bound to two protons 2) Two electrons are bound to two protons 3) Three electrons are bound to two protons 4) none of these happens 138. Which of the following pairs have nearly identical values of bond energy? 1) O2 and H2 2) N2 and CO 3) F2 and I2 4) O2 and Cl2 139. The molecular sizes of ICl and Br2 are nearly the same, but the boiling point of ICl is about 390C higher

140.

141.

142.

143.

than that of Br2. This is because : 1) the bond energy of I–Cl is greater than that of Br – Br 2) The ionization energy of iodine is less than that of bromine 3) ICl is polar while Br2 is nonpolar 4) The size of iodine is greater than that of bromine Which of the following factors is the most responsible for increase in boiling point as we move from He to Xe? 1) Decrease in ionization energy 2) Increasing in electronegativity 3) Decrease in polarizability 4) Increase in polarizability Hydrogen bonding is exhibited by 1) all substances containing H-atoms 2) Molecules in which hydrogen is bonded to F, O or N 3) Molecules in which one hydrogen is bonded to F and the other is bonded to Cl 4) All substances containing H and O atoms The density of water is greater than that of ice because of 1) dipole-dipole interaction 2) hydrogen bonding 3) dipole-induced dipole interaction 4) covalent bond formation Which of the following is true? 1) Bond order µ

1 1 µ bond energy 2) Bond order µ bond length µ bond length bond energy

1 1 3) Bond order µ bond length µ bond energy 4) Bond order µ bond length µ bond energy

144. Which of the following has been arranged in order of decreasing bond length? 1) P – O > Cl – O > S – O 2) P – O > S – O > Cl – O 3) S – O > Cl – O > P – O 4) Cl – O > S – O > P – O 145. During the formation of a molecular orbital from atomic orbitals, the electron density is 1) minimum in the nodal plane 2) maximum in the nodal plane 3) zero in the nodal plane 4) zero on the surface of the lobe 146. The oxygen molecule is paramagnetic because 1) the bonding electrons out number the antibonding electrons in the molecular orbital 2) it contains unpaired electrons in the antibonding molecular orbitals 3) it contains unpaired electrons in the bonding molecular orbitals 4) the number of bonding electrons equal that of the antibonding electrons in the molecular orbitals 147. If a molecule MX3 has zero dipole moment, the sigma bonding orbitals used by M(atomic number < 21) are

148.

149.

150. 151. 152.

1) pure P 2) sp hybrid 3) sp2 hybrid 4) sp3 hybrid The volatility of HF is low because of 1) its low polarizability 2) the weak dispersion interaction between the molecules 3) its small molecular mass 4) its strong hydrogen bonding Which of the following have dipole moment? 1) 1, 4-dichlorobenzene 2) cis-1, 2-dichloroethene 3) trans-1, 2-dichloroethene 4) trans-1, 2-dichloropentene Which of the following has the least dipole moment? 1) NF3 2) CO 3) SO2 4) NH3 Which of the following is the least polar? 1) HF 2) HBr 3) HI 4) HCl Which of the following have been arranged in increasing order of bond order as well as bond dissociation energy? 1) O2-2 < O2- < O2+ < O2

153.

154. 155.

156.

2) O2-2 < O2- < O2 < O2+

3) O2 < O2+ < O22- < O24) O2+ < O22- < O2- < O2 Orthonitrophenol is steam volatile but paranitrophenol is not because 1) Orthonitrophenol has intramolecular hydrogen bonding while paranitrophenol has intermolecular hydrogen bonding 2) Both ortho and paranitrophenol have intramolecular hydrogen bonding 3) Orthonitrophenol has intermolecular hydrogen bonding and paranitrophenol has intramolecular hydrogen bonding 4) Vander Waals forces are dominant in orthonitrophenol The maximum possible number of hydrogen bonds in which a water molecule can participate is 1) four 2) three 3) two 4) one 2 3 The overlapping powers (overlap integrals) of 2s, 2p, 2sp , 2sp and 2sp orbitals are in the order 1) 2s > 2p > 2sp3 > 2sp2 > 2sp 2) 2p > 2s > 2sp3 > 2sp2 > 2sp 3) 2sp3 > 2sp2 > 2sp > 2s > 2p 4) 2sp3 > 2sp2 > 2sp > 2p > 2s Which of the following pairs is diamagnetic according to MOT? 1) O2- and O22-

2) B2 and C2

3) N 2+ and O2+

4) O2+ and H 2+

157. Mark the correct statement(s) in the following : 1) The bond order in the species O2 , O2+ and O2- decreases as O2+ > O2 and O22) The bond energy in a diatomic molecule always increases when an electron is lost 3) Electrons in antibonding M.O contribute to repulsion between two atoms 4) With increase in bond order bond length decreases and bond strength increases 158. Increasing order of strength of hydrogen bonding in X ........... H – X for X among O, S, F, Cl and N is 1) Cl < N < O < F 2) Cl < S < O < N 3) S < Cl < N < O 159. The bond angle in NH3 is 1) Less than that in H2O but greater than that in H2S 2) Greater than that in H2O but less than that in H2S 3) Less than both those of H2O and H2S 4) Greater than both those of H2O and H2S

4) Cl < S < O < F

160.

In the following species, the one having a planar structure is 1) BF4-

3) BrF4-

2) SnCl4

4) NH 4+

161. H2, Li2, B2 each has bond order equal to 1, the order of their stability is 1) H2 = Li2 = B2 2) H2 > Li2 > B2 3) H2 > B2 > Li2 162. Which of the following facts given is not correct?

4) B2 > Li2 < H2

I) Bond length order : H 2- = H 2+ > H 2 1 2 III) Bond order can assume any value including zero

II) O2+ , NO, N 2- have same bond order of 2

IV) NO3- and BO3- have same bond order for X - O bond (where X is central atom) 1) I, II and III 2) I and IV 3) II and IV 4) I and II 163. Which of the following have identical bond order? (I) CN (II) O2(III) NO+ (IV) CN+ 1) I, III 2) I, II 3) II, III 4) I, II, III + 164. Among KO2, AlO2 , BaO2 and NO2 , unpaired electron is present in 1) KO2 only 2) NO2+ and BaO2 3) KO2 and AlO24) BaO2 only – 2– – 165. Which is the correct order of size of O , O , F and F 1) O2– > F– > O– > F

2) O2– > F– > F > O–

3) O– > O2– > F > F–

4) O2– > O– > F– > F

166. The geometry of ammonia molecule can be best described as 1) nitrogen at one vertex of a regular tetrahedron, the other three vertices being occupied by the three hydrogens 2) nitrogen at the centre of the tetrahedron , three of the vertices being occupied by three hydrogens 3) nitrogen at the centre of equilateral triangle, three corners being occupied by three hydrogens 4) nitrogen at the juction of a ‘T’ three open ends being occupied by three hydrogen 167. The compound with the highest degree of covalency is : 1) NaCl 2) MgCl2 3) AgCl 4) CsCl 168. A molecule XY2 contains two s, two p-bonds and one lone pair of electron in the valence shell of X. The arrangement of lone pair as well as bond pairs is : 1) square pyramidal 2) linear 3) trigonal planar 4) unpredictable 169. The compound with the highest degree of covalency is : 1) NaCl 2) MgCl2 3) AgCl 4) CsCl 170. A molecule XY2 contains two s, two p-bonds and one lone pair of electron in the valence shell of X. The arrangement of lone pair as well as bond pairs is : 1) square pyramidal 2) linear 3) trigonal planar 4) unpredictable 171. The tetrahedral geometry of methane instead of squareplanar structure is supported by : 1) Its dipolemoment value 2) Its mono chlorination 3) Its dichlorination 4) Its trichlorination 172. Which of the following is the correct electron dot structure of N2O molecule? ..

1) : N = N = O :

+

..

2) : N º N = O. . :

-

..

..

..

3) N = N = O : ..

..

4) : N = N = O. . :

173. The molecular size of ICl and Br2 is approximately same, but boiling of ICl is about 400 higher than that of Br2. It is because 1) ICl bond is stronger than Br – Br bond

2) IE of iodine < IE of Br

3) ICl is polar while Br2 is nonpolar

4) I has larger size than Br

174. The molecule MLx is planar with six pairs of electrons around ‘M’ in the valence shell. The value of ‘x’ is 1) 6 2) 2 3) 4 4) 3 175. Metals possess lustre when freshly cut because 1) They have a hard surface and light is reflected back 2) Their crystal structure contains ordered arrangement of their constituent atoms 3) They contain loosely bound electrons which absorb the photons and then re-emit 4) They are obtained from the minerals on which light has been falling for years 176. Mark the incorrect statement in the following :

177.

178. 179. 180. 181.

1) The bond order in the species O2 , O2+ and O2- decreases as O2+ > O2 > O22) The bond energy in a diatomic molecule always increases when an electron is lost 3) Electrons in antibonding M.O. contribute to repulsion between two atoms 4) With increase in bond order, bond length decreases and bond strength increases Amongst LiCl, BeCl2, MgCl2 and RbCl the compounds with greatest and least ionic character, respectively are : 1) LiCl and RbCl 2) RbCl and BeCl2 3) RbCl and MgCl2 4) MgCl2 and BeCl2 The compound with the highest degree of covalent character is : 1) NaCl 2) MgCl2 3) AgCl 4) CsCl The pair of species with similar shape is : 1) PCl3, NH3 2) CF4, SF4 3) PbCl2, CO2 4) PF5, IF5 The state of hybridization of the central atom is not the same as in the others : 1) B in BF3 2) O and H3O+ 3) N in NH3 4) P in PCl3 Which is the following pairs of species have identical shapes?

1) NO2+ and NO22) PCl5 and BrF5 3) XeF4 and ICl44) TeCl4 and XeO4 182. The hybridization of the central atom will change when : 1) CH3 combines with H+ 2) H3BO3 combines with OH– 3) NH3 forms NH 24) H2O combines with H+ 183. In which of the following compounds B – F bond length is shortest? 184. 185.

186. 187.

1) BF42) BF3 ¬ NH 3 3) BF3 4) BF3 ¬ N ( CH 3 )3 Which molecular geometry is least likely to result from a trigonal bipyramidal electron geometry? 1) Trigonal planar 2) See-saw 3) Linear 4) T-shaped Give the correct order of initials T or F for following statements. Use ‘T’ if statement is true and F if it is false I) The order of repulsion between different pair of electrons is lp – lp > lp – bp > bp – bp II) In general, as the number of lone pair of electrons on central atom increases, value of bond angle from normal bond angle also increases III) The number of lone pair on O in H2O is 2 while on N in NH3 is 1 IV) The structures of xenon fluorides and xenon oxyfluorides could not be explained on the basis of VSEPR theory 1) TTTF 2) TFTF 3) TFTT 4) TFFF The correct increasing order of adjecent bond angle among BF3, PF3 and ClF3 1) BF3 < PF3 < ClF3 2) PF3 < BF3 < ClF3 3) ClF3 < PF3 < BF3 4) BF3 = PF3 = ClF3 The bond angles of NH3, NH4+ and NH2– are in the order

1) NH 2- > NH 3 > NH 4+

2) NH 4+ > NH 3 > NH 2-

3) NH 3 > NH 2- > NH 4+

4) NH 3 > NH 4+ > NH 2-

188. The compound MX4 is tetrahedral. The number of H 2 1 2 III) Bond order can assume any value including zero

II) O2+ , NO, N 2- have same bond order of 2

IV) NO3- and BO3- have same bond order for X - O bond (where X is central atom) 1) I, II and III 2) I and IV 3) II and IV 4) I and II 197. Identify the correct sequence of increasing number of p - bonds in the structures of the following molecules I) H2S2O6 II) H2SO3 III) H2S2O5

1) I, II, III 2) II, III, I 3) II, I, III 198. Which combination will give the strongest ionic bond? 1) Na+ and Cl– 2) Mg2+ and Cl– 3) Na+ and O2– 199. H2, Li2, B2 each has bond order equal to 1, the order of their stability is 1) H2 = Li2 = B2 2) H2 > Li2 > B2 3) H2 > B2 > Li2 200. Which of the following have undistorted octahedral structures?

4) I, III, II 4) Mg2+ and O2– 4) B2 > Li2 < H2

b) PF6c) SiF624) XeF6 Select the correct answer using the codes given below : 1) b, c and d 2) a, c and d 3) a, b and c 4) a, b and d 201. Sulphur reacts with chlorine in 1:2 ratio and forms X. Hydrolysis of X gives sulphur compound Y. What is the hybridization state of central atom in the anion of Y? 1) sp3 2) sp 3) sp2 4) sp2d 202. Which of the following is correct? 1) The number of electrons present in the valence shell in SF6 is 12. 2) The rates of ionic compounds are very slow 3) According to VSEPR, SnCl2 is linear molecule 4) The correct order of ability to form ionic compounds among Na+, Mg2+ and Al3+ is Al3+ > Mg2+ > Na+ a) SF6

203. A molecule may be represented by three structures having energies E1, E2 and E3, respectively. The energies of these structures follow the order E3 < E2 < E1, respectively. If the experimental bond energy of the molecule is E0, the resonance energy is : a) (E1 + E2 + E3) – E0 b) E0 – E3 c) E0 – E1 d) E0 – E2 204. The HOMO in nitric oxide molecule is * * 1) p2 py = p2 pz 2) p 2 py = p 2 pz 3) s2 px 4) s* 2 px 205. In which species is the electron pair geometry is the same as the molecular geometry 1) BeF2 2) PF3 3) SF4 4) IF5 206. A simplified application of M.O theory to the hypothetical ‘molecule’ of would give its bond order as 1) 2 2) 1.5 3) 1.0 4) 0.5 207. Which of the following is true?

1 1) Bond order a bond length a bond energy

1 2) Bond order a bond length a bond energy

1 1 3) Bond order a bond length a bond energy

4) Bond order a bond length a bond energy

208. Which of the following compounds have the same number of lone pairs with their central atom I) XeF5II) BrF3 III) XeF2 IV) H 3 S + V) XeO641) IV and V 2) I and III 3) I and II 4) II, IV and V 209. Select pair of compounds in which both have different hybridization but have same molecular geometry 2) ICl2- , BeCl2 210. Which of the following are non-polar 1) BF3, BrF3 1) SO3

2) BF3

3) BCl3, PCl3

4) PCl3, NCl3

3) CO32-

4) NO3-

211. If there is no sp mixing the bond and magnetic character in C2 molecule is 1) 1 and paramagnetic 2) 1 and diamagnetic 3) 2 and paramagnetic 4) 2 and diamagnetic

212. The strongest P – O bond is found in the molecule 1) F3P = O 2) Cl3P = 0 3) Br3P = 0 4) (CH3)3P = 0 213. F – As – F bond angle in AsF3Cl2 can be 1) 900 and 1800 only 2) 1200 only 3) 900 and 1200 only 4) 900 only 214. In which of the following ionization processes, the bond order has increased and the magnetic behaviour has changed 1) C2 ¾¾ 2) NO ¾¾ 3) O2 ¾¾ 4) N 2 ¾¾ ® C2+ ® O2+ ® N 2+ ® NO+ 215. Which statement is incorrect? 1) Higher the polarisation, higher will be relative solubility in non-polar solvent 2) Higher is the polarisation, higher will be the intensity of colour 3) Diamagnetic substances some times become coloured due to HOMO – LUMO transition 4) Higher is the polarization in metal oxide, higher will be the basic character

Assertion (A) & Reason (R) type questions : 301. Assertion (A) : Solubility of n-alcohol in water decreases with increase in molecular weight Reason (R) : The hydrophobic nature of alkyl chain increase 302. Assertion (A) : The p-isomer of dichlorobenzenehas higher melting point than o – and m-isomer Reason (R) : p-isomer is symmetrical and thus shows more closely packed structure 303. Assertion(A) : Bond order in a molecule can assume any value, positive or negative, integral or fractional including zero. Reason(R) : It depends upon the number of electrons in the bonding and antibonding orbitals 304. Assertion(A) : LiCl is predominantly a covalent compound. Reason(R) : Electronegativity difference between ‘Li’ and ‘Cl’ is too small 305. Assertion (A) : Salts of ClO3- and ClO4- are well known but those of FO3- and FO4- are non existent Reason (R) : F is more electronegative than ‘O’ while Cl is less electronegative than O 306. Assertion (A) : Bond energy of Cl – Cl bond is more than F – F bond Reason (R) : Shorter the bond length, stronger the bond, more is the bond energy 307. Assertion (A) : Octet theory cannot account for the shape of the molecule Reason (R) : Octet theory can produce relative stability and energy of a molecule 308. Assertion (A) : Carbonates and silicates are iso structural Reason (R) : Carbon and silicon have the same number of valence shell electrons 309. Assertion (A) : The dipolemoment of NF3 is less than that of NH3 Reason (R) : The polarity of the N – F bond is less than that of the N – H bond 310. Assertion (A) : The boiling point of H2O is greater than H2S Reason (R) : Both H2O and H2S contains hydrogen bond 311. Statement – I : Born - Haber cycle is based on Hess’s law Statement – II : Lattice enthalpy can be calculated by Born-Haber cycle 312.. Assertion (A) : As lattice energy increases, melting and boiling points of ionic compound increases. Reason (R) : As lattice energy increases, stability of ionic compoind increases. 313. Assertion (A) : In triangular bipyramidal hybridization a loan pair preferentially occupies equatorial position Reason (R) : The most electronegative bonding partner/s preferentially occupy the axial positions in triangular bipyramidal structure 314. Assertion (A) : Covalent bond is more stable than ionic bond Reason (R) : A ionic bond is formed by transfer of electron from one atom to another atom 315. Assertion (A) : Antibonding molecular orbital posses higher energy relative to the constituent atomic orbitals Reason (R) : The probability of finding the electrons in antibonding molecular orbitals is less than constituent atomic orbitals 316. Assertion (A) : The melting point of ZnCO3 and Cd CO3 is found to be low in comparison to CaCO3 Reason (R) : The polarising power of Zn2+ and Cd2+ is much higher than the polarising power of Ca2+ 317. Assertion (A) : Diethyl ether is insoluble in water Reason (R) : Diethyl ether can form hydrogen bond with water 318. Assertion (A) : If there are two pairs of electrons with valence shell of the central atom the orbitals containing them will be oriented at 1800 to each other Reason (R) : The orbitals is CO2 overlaps at 1800C then the CO2 mole is linear 319. Assertion (A) : For p overlap the lobes of the atomic orbitals are perpendicular to the line joining the

320. 321. 322.

323. 324. 325. 326.

nuclei Reason (R) : p molecular orbitals Y is zero along the internuclear axis Assertion (A) : AgCl is more covalent than KCl Reason (R) : Polarizing power of K+ is more than the polarising power of Ag+ ions Assertion (A) : In liquid water the hydrogen bonds are constantly swapping between molecules Reason (R) : Water is one of the substance that is less dense as a solid that it is as a liquid Assertion (A) : In an insulator the valence band is full and electrons cannot gain energy and move within this band Reason (R) : In an n-type semicoductor the impurity provides an excess of electrons Assertion (A) : AgCl is more covalent than KCl Reason (R) : Polarizing power of K+ is more than the polarising power of Ag+ ions Assertion (A) : The dipole moment helps to predict whether molecule is polar or non-polar Reason (R) : The dipole moment helps to predict the geometry of molecules Assertion(A): Glucose is soluble in polar solvent like water Reason(R): Ionic compounds dissolved in polar solvants Assertion(A): Bond order in carbon monoxide is three Reason(R): The HOMO of carbon monoxide is p * 2 p y = p * 2 pz

327. Statement (I) : Na+ and Al3+ are isoelectronic but the magnitude of the ionic radius of Al3+ is less than that of Na+ Statement (II) : The magnitude of the effective nuclear charge on the outer shell electrons in Al3+ is greater than that in Na+ 328. Statement (I) : Fe3+ salts are less stable than Fe2+ salt Statement (II) : Fe3+ ions are formed by loss of ‘s’ and ‘d’ electrons while Fe2+ ions are formed by loss of only ‘s’ electrons 329. Statement (I) : H2 molecule is more stable than HeH molecule Statement (II) : The antibonding electron in the molecule destabilizes it 330. Assertion(A) : Bond order in a molecule can assume any value, positive or negative, integral or fractional including zero. Reason(R) : It depends upon the number of electrons in the bonding and antibonding orbitals 331. Assertion(A) : LiCl is predominantly a covalent compound. Reason(R) : Electronegativity difference between ‘Li’ and ‘Cl’ is too small 332. Assertion(A) : The O–O bond length in H2O2 is shorter than that of O2F2 Reason(R) : H2O2 is an ionic compound

More than one answer questions : 401. CO2 molecule is not isostructural with : 1) HgCl2 2) SnCl2 3) C2H2 4) NO2 402. Correct order of decreasing boiling points is : 1) HF > HI > HBr > HCl 2) H2O > H2Te > H2Se > H2S 3) Br2 > Cl2 > F2 4) CH4 > GeH4 > SiH4 403. Which of the following statements are correct about sulphur hexaflouride? 1) all S – F bonds are equivalent

2) SF6 is a planar molecule 3) Oxidation number of sulphur is the same as number of electrons of sulphur involved in bonding 4) Sulphur has acquired the electronic structure of the gas argon 404. Which of the following process is/are associated with change of hybridization of the underlined compound? 1) Al(OH)3 ppt. dissolved in NaOH 2) B2H6 is dissolved in THF 3) SiF4 vapour is passed through liq. HF 4) Solidification PCl5 vapour 405. Which combination of compounds, their geometry and hybridization are correct ? 1) XeF4 -square planar, sp 3d 2

2) BeF3- -trigonal planar, sp2

3) NH 2- -linear, sp

4) CIF3 - T shaped, sp3d

406. Which of the following molecules has unpaired electrons in antibonding orbitals ? 1) CO

2) O2-

3) O2+

4) N 2+

407. Select the correct statement (s) of the following : 1) NF3 is a weaker base than NH 3 or NCl3 2) AlCl3 is largely covalent while AlF3 is large ionic 3) A triple bond between two atoms may be made up of two sigma and one pi bonds 4) N 3- ion is more susceptible to polarisation than O 2- ion 408. In which of the following changes(s), hybridisation of the underlined atom is not affected ? + ® PH 4+ 1) -P H 3 + H ¾¾

® H 2 S ® BF3 2) -B F3 + H 2 S ¾¾

® HBO2 + H 2O 3) H3 -BO3 ¾¾

® HClO + HClO3 __ O2 ¾ ¾ 4) 2H Cl

409. Which of the following is/are correct statement(s)? 1) H–F molecule forms two hydrogen bonds 2) Alcohols are soluble in water 3) Hydrogen bond is generally formed by covalent compounds 4) Hydrogen bond is not formed in non polar covalent compounds 410. Which of the following statements are not correct? 1) All C – O bonds in CO32- are equal but not H2CO3 2) All C – O bonds in HCO2- are equal but not HCO2H 3) C – O bond length in HCO2- is longer than C – O bond length in CO324) C – O bond length in HCO2- and C – O bond length in CO32- are equal 411. Intermolecular hydrogen bonding increases the enthalpy of vaporization of a liquid due to the 1) decrease in the attraction between molecules 2) increase in the attraction between molecules 3) decrease in the molar mass of unassociated liquid molecules

4) increase in the effective molar mass of hydrogen-bonded molecules 412. Which of the following are paramagnetic? 1) B2 2) O2 3) N2 4) He2 413. Which of the following is/are correct statement(s)? 1) Probability of finding the electron in bonding molecular orbital is more than combining atomic orbitals 2) Bonding molecular orbitals are formed when same sign of orbitals are overlap 3) d–d combination of atomic orbitals gives d and d* molecular orbitals 4) None of these 414. According to MOT (Molecular Orbital Theory), the molecular orbitals are formed by mixing of atomic orbitals through LCAO (linear combination of atomic orbitals). The correct statement(s) about molecular orbitals is/are 1) bonding molecular orbitals are formed by addition of wave-functions of atomic orbitals 2) anti-bonding molecular orbitals are formed by subtraction of wave-functions of atomic orbitals 3) non-bonding molecular orbitals do not take part in bond formation because they belong to inner shells 4) anti-bonding molecular orbitals provide stability to molecules while bonding molecular orbitals make the molecules unstable. 415. Depending on the Lewis structures of OF2, O2F2 and S2F2 which of the following statements are correct 1) S2F2 has two possible isomeric structures where as O2F2 has only one 2) The bond angle in OF2 is 1030 but that in OCl2 is 1110 3) The O – O bond distance in O2F2 is only 1.22 A0 but that in H2O2 is 1.48 A0 4) The O – F bond length in O2F2 is 1.58 A0 but that in OF2 is only 1.41 A0 416. In which of the following pairs, both the species have the same state of hybridisation 1) éë NO3- , NH 2- ùû 2) éë NH 2- , H 3O + ùû 3) éë BF3 , CH 3+ ùû 417. In which of the following sets all the species are paramagnetic in nature?

4) PCl4+ , NH 4+

1) O2 , O22+ , N 22 2) B2 C2 H2 3) O2- O2+ O2 418. Which of the following reaction involves an increase in bond length

4) N 2+ O2+ F2+

1) N 2 ¾¾ 2) O2 ¾¾ ® N 2+ ® O2+ 419. Which of the following statements is incorrect ?

3) C2 ¾¾ ® C22-

4) O2- ¾¾ ® O2

1) In O2 F2 , the O-O bond is shorter than the O-O bond in H 2O2 2) In O2 F2 , the O-O bond is longer than the O-O bond in H 2O2 3) H 2O2 and O2 F2 have similar structures, hence the O-O bond of the two molecules are identical. 4) O2 F2 does not contain the peroxide bond -O - O -. 420. HClO4, HNO3 and HCl are all very strong acids in aqueous solution. In glacial acetic acid medium, their acid strength is such that : 1) HClO4 > HNO3 > HCl 2) HNO3 > HClO4 > HCl 3) HCl > HClO4 > HNO3 4) HCl > HClO4 ~ HNO3 421. The species that undergo disproportionation in an alkaline medium are 1) Cl2

2) MnO42-

3) NO2

4) ClO4-

422. The molecule |ion having last electron in the anti bonding p molecular orbital are/is 1) O2 2) Fe2+ 3) Ne2 4) N2+ 423. The correct statement about sulphur hexa fluoride include 1) There are 12 F – S – F 900 bond angles 2) S in SF6 has an expanded octet 3) With H2O, SF6 can accept lone pair of electron with empty 3d atomic orbital and gets hydrolysed 4) SF6 has a distorted octahedral geometry 424. Correct statements about CH2F2 molecule a) All bond angles are equal b) F – C – F bond angle is less than H – C – H bond angle c) Dipole moment value is not equal to zero d) H – C – H bond angle is greater than tetrahedral bond angle 425. Which of the following statements is/are NOT correct for following compounds? 1) SCl2(OCH3)2 and (II) SF2(OCH3)2 1) –OCH3 groups in both cases occupy the same position 2) Cl-atoms occupy equitorial position in case of (I) and F-atoms occupy equitorial position in case of (II) 3) Cl-atoms occupy axial position in case of (I) and F-atoms occupy equitorial position in case of (II) 4) Cl and F-atoms occupy either axial or equitorial position in case of (I) and (II) respectively 426. Which of the following statement is/are correct A) The peroxide ion has a bond order of 1 while the oxygen molecule has a bond order of 2 B) The peroxide ion has a weaker bond than the dioxygen molecule has C) The peroxide ion as well as the dioxygen molecules are paramagnetic D) The bond length of the peroxide ion is greater than that of the dioxygen molecule 427. Mark the correct statement(s) in the following : 1) The bond order in the species O2 , O2+ and O2- decreases as O2+ > O2 and O22) The bond energy in a diatomic molecule always increases when an electron is lost 3) Electrons in antibonding M.O contribute to repulsion between two atoms 4) With increase in bond order bond length decreases and bond strength increases 428. Most ionic compounds have a) high melting points and low boiling points b) high melting points and nondirectional bonds c) high solubilities in polar solvents and low solubilities in non polar solvents d) three-dimensional network structues, and are good conductors of electricity in the molten state 429. Which of the following pairs have identical values of bond order? a) N 2+ and O2+ b) F2 and Ne2 c) O2 and B2 d) C2 and N2 430. Intermolecular hydrogen bonding increases the enthalpy of vaporization of a liquid due to the a) decrease in the attraction between molecules b) increase in the attraction between molecules c) decrease in the molar mass of unassociated liquid molecules d) increase in the effective molar mass of hydrogen-bonded molecules 431. Which of the following are paramagnetic? a) B2 b) O2 c) N2 d) He2 432. Which of the following is correct? a) During N2+ formation, one electron each is removed from the bonding molecular orbitals b) During O2+ formation, one electron each is removed from the antibonding molecular orbitals c) During O2- formation, one electron each is added to the bonding molecular orbitals

d) During CN - formation, one electron each is added to the bonding molecular orbitals 433. Which of the following have an (18 + 2) - electron configuration? 1) Pb2+

2) Cd2+

434. Which of the following statement is incorrect: 1) O2 is paramagnetic, O3 is also paramagnetic 3) B2 is paramagnetic, C2 is also paramagnetic

3) Bi3+

4) SO42-

2) O2 is paramagnetic, O3 is diamagnetic

4) Different observation is foundin their bond length when NO ¾¾ ® NO+ and CO ¾¾ ® CO+ 435. Which of the following is/are correct statement(s)? 1) H–F molecule forms two hydrogen bonds 2) Alcohols are soluble in water 3) Hydrogen bond is generally formed by covalent compounds 4) Hydrogen bond is not formed in non polar covalent compounds 436. Which of the following isomerisms is exhibited by [Cr(NH3)2(H2O)2Cl2]Cl 1) Ionisation 2) Geometrical 3) Hydrate 4) Optical 437. Which of the following species are linear? 1) N 32) I 33) ICl 2438. Which of the following species have equal bond order? 1) H 2+

2) H 2-

3) N

4) ClO2 4) O2+

439. Consider the following correct statements : 1) Dispersion forces are evergreen and exist between all atoms, molecules and ions 2) The extent of ion induced dipole interaction depends only on the charge on ion 3) Dry ice is held together by a netwrok of C = O bonds 4) Among the hydrides of second period, decreasing order of boiling points is HF > H2O > NH3 > CH4 440. Which of the following set of compounds are isoelectronic and isostructural 1) CO2, CS2, CNO–, CN 22-

2) SO32- , ClO3- , BrO3- , XeO3

3) BF4- , NH 4+ , CH 4 , SiH 4

4) SO2Cl2 , POCl3 , ClO4- , XeO4

441. Which of the following compound/compounds do not conduct electricity in their molten state? 1) MgCl2 2) BeCl2 3) BeF2 4) MgF2 442. In which of the following, the hybrid orbitals of the central metal atom have the same s-character? 1) CH4 2) XeO3 3) Ni(CO)4 4) [Ni(CN)4]2– 443. The compound/s which contain ionic, covalent and coordinate bonds is/are 1) H2SO4 2) NH4Cl 3) K4[Fe(CN)6] 4) CaC2 444. The molecules or ions which have bond pairs as well as lone pairs of electrons on the central atom are 1) SF4 2) ClF3 445. Select the correct statement(s)

3) XeF2

4) CO32- ion

1) NF3 is weaker base than NH3 2) NO+ is more stable than O2+ 3) AlCl3 has higher m. pt than AlF3 4) SbCl3 is more covalent than SbCl5 446. Which of the following is/are correct statement(s)?

1) H–F molecule forms two hydrogen bonds 2) Alcohols are soluble in water 3) Hydrogen bond is generally formed by covalent compounds 4) Hydrogen bond is not formed in non polar covalent compounds 447. Which of the following relation is/are correct? 1) Covalent character a

1 Dipole moment

2) Covalent character a Pseudo inert configura-

tion 3) Ionic character a inert configuration

4) Ionic character a

1 Dipole moment

448. Which of the following is/are correct statement(s)? 1) Probability of finding the electron in bonding molecular orbital is more than combining atomic orbitals 2) Bonding molecular orbitals are formed when same sign of orbitals are overlap 3) d–d combination of atomic orbitals gives d and d* molecular orbitals 4) None of these 449. Cu2Cl2 is more covalent than CuCl2. This can be justified on the basis of 1) VSEPR theory 2) hybridization 3) Fajan’s rule 4) hydration energy 450. Which of the following is/are correct relation? 1) Bond energy a (polarity in the bond)1 2) Bond energy a (s-character is hybridization)1 –1 3) Bond energy a (atomic radius) 4) Bond energy a (bond order)1 451. Which of the following are isostructural? N 3I 3(I) (II) 1) I, II and III 2) I and III 452. Mark the correct statement(s) in the following :

N 2O (III) 3) I, III and IV

NO 2 (IV) 4) II and III

1) The bond order in the species O2 , O2+ and O2- decreases as O2+ > O2 and O22) The bond energy in a diatomic molecule always increases when an electron is lost 3) Electrons in antibonding M.O contribute to repulsion between two atoms 4) With increase in bond order bond length decreases and bond strength increases 453. Which have fractional bond order 1) O2+ 2) O23) NO 4) H 2+ 454. Which of the statement(s) is/are correct 1) The peroxide ion has a bond order of 1 while the oxygen molecule has a bond order of 2 2) The peroxide ion has weaker bond than the dioxygen molecule has 3) The peroxide ion as well as the dioxygen molecules are paramagnetic 4) The bond length of the peroxide ion is greater than that of the dioxygen molecule 455. According to MOT (Molecular Orbital Theory) the molecular orbitals are formed by mixing of atomic orbitals through Ð CAO (linear combination of atomic orbitals) the correct statement(s) about molecular orbitals is/are Statement (a) : Bonding molecular orbitals are formed by addition of wave functions of atomic orbitals of same phase Statement (b) : Antibonding molecular orbitals are formed by subtraction of wave functions of atomic orbitals of same phase Statement (c) : Non-bonding molecular orbitals do not take part in bond formation because they belong to inner shells Statement (d) : Antibonding molecular orbitals provide stability to molecules while bonding molecular orbitals make the molecules unstable

1) Statement a and d 2) Statement a, b and c 3) Statement a, b and d 4) Statement a and b 456. In which of the following compounds having general formula X2H6 there is no X – X bond 1) B2H6

2) C2H6

3) Al2H6

4) Si2H6

1) Cr2O72-

2) S 2O32-

3) Pyrosilicate

4) Hypo nitrous acid

457. A p bond may between two Px orbitals containing one unpaired electron each when they approach each other approximately along 1) X-axis 2) Y-axis 3) Z-axis 4) any direction 458. A, B, C are three substances. A does not conduct electricity in the solid state, molten state and aqueous solution. B conducts electricity both in the fused and aqueous states, while conducts electricity only in the aqueous state. In solid state neither B nor C conducts electricity. Which of the following statements is/are the regarding A, B and C? 1) A has polar covalent linkage 2) A has non polar covalent linkage 3) B is ionic in nature 4) Cation formed by C is highly polarizing 459. Intermolecular hydrogen bonding increases the enthalpy of vapourization of a liquid due to the 1) Decrease in the attraction between molecules 2) Increase in the attraction between molecules 3) Decrease in the molar mass of unassociated liquid molecules 4) Increase in the effective molar mass of hydrogen bonded molecules 460. Which of the following have X – O – X linkage (where X is central atom)

Comprehensions type questions: Passage – I : According to MOT, two atomic orbitals overlap resulting in the formation of molecular orbitals. Number of atomic orbitals overlapping together is equal to the molecular orbital formed. The two atomic orbital thus formed by LCAO (linear combination of atomic orbital) in the same phase or in the different phase are known as bonding and antibonding molecular orbitals respectively. The energy of bonding molecular orbital is lower than that of the pure atomic orbital by an amount D. This known as the stabilization energy. The energy of antibonding molecular orbital is increased by D ' (destabilisation energy) 501. Which among the following pairs contain both paramagnetic species 1) O22- and N 2-

2) O2- and N 2

3) O2 and N2

4) O2 and N 2-

502. How many nodal plane is present in s ( s and p ) bonding molecular orbital? 1) zero 2) 1 3) 2 4) 3 503. Which of the following statements is not correct regarding bonding molecular orbitals? 1) Bonding molecular orbitals possess less energy than the atomic orbitals from which they are formed 2) Bonding molecular orbitals have low electron density between the two nuclei

3) Electron in bonding molecular contributes to the attraction between atoms 4) They are formed when the lobes of the combining atomic orbitals have the same sign 504. If x-axis is the molecular axis, then p-molecular orbitals are formed by the overlap of : 1) s + pz 2) px + py 3) pz + pz 4) px + px Passage - II: The shapes of molecules can be predicted by VSEPR theory, hybridization and dipole moment. Total number of hybrid orbitals(H) on the central atom of a molecule can be calculated by using the following relation : H = [ Total no.of valence electron pairs ( P) - 3´(no. of atoms surrounding the central atom, excluding Hydrogen atoms)] One can also calculate total no. of bond pairs (n) around central atom as n = total number of atoms surrounding the central atom also, total no.of lone pairs (m) = H - n Thus, VSEPR notation of a molecule can be written as AX n Em . Where, a denotes central atom of the molecule X denotes bond pairs on central atom of the molecule E denotes lone pairs on central atom of the molecule In a polar molecule, the net dipole moment of the molecule µ m . 505. VSEPR notation of chlorine trifluoride molecule is. 1) AX 5

2) AX 3

3) AX 2 E3

4) AX 3 E2

506. Some molecules are given below. CO2, I

SO2, H2O II

III

The incorrect increasing order of dipole moment of given species is. 1) I < II < III

2) II < I < III

3) III < II < I

4) III < I < II

507. Total number of hybrid orbitals central iodine in tri-iodide ion, are 1) 2

2) 3

3) 4

4) 5

Passage – I : Departure From Normal Hybridisation Departures from normal hybridisations is quite prevalent. To begin, we will define hybridisation index ( i ) of a hybrid orbital as the superscript on p in the label. Thus, for sp3, i = 3. From this definition we can deduce the following relationships.

fs =

1 i +1

O sp

180

q

150

interorbital angle 120

sp 3

O

O

sp 2

90 1/ 10

1/ 2

Fraction of S character( f s )

fp =

i=

i i +1

fp fs

åf

s

=1

f s + f p =1 Finally, the relationship that generates the curve in the above figure is

cos q =

-1 i

where q is the interorbital angle

508. Bond angle in methane is 1090 28' . The hybrid orbitals used in the formation of methane are 1) sp3 2) sp2 3) sp3.5 4) sp2.5 509. Bond angle of ammonia is 107.10. What nitrogen hybrids are used in the formation of N-H bonds? (cos1070 = - 0.2923) 1) sp3 2) sp3.4 3) sp2.5 510. What type of nitrogen hybrid contains the nonbonding pair? 1) sp2 2) sp2.13 3) sp3

4) sp4 4) sp2.9

Passage : Bond length is the average distance between the nuclei of the two atoms held by a bond. This represents the internuclear distance corresponding to mininum potential energy for the system. Main factors which affet the bond length are given below : (I) Multiple bonds are shorter than corresponding single bonds (II) Sometimes single bond distances are some what shorter than double of their respective covalent radii because bonds acquire some partial double bond character. This normally happens when one atom having vacant orbital and another atom containing lone pair. It is possible that it becomes shorter

due to high ionic character in the covalent bond.

511. Which is not true about the N – N bond length among the following species? I) H2N – NH2

II) N2

+ + III) H 3 N - N H 3

IV) N2O

1) N – N bond length is shortest in II 2) N – N bond length in I is shorter than that in III 3) N – N bond length in III is shorter than that of in I 4) N – N bond length IV is intermediate between I and II 512. In which of the following cases central atom - F bond has partial double bond character? 1) NF3 2) CF4 3) PF3 4) OF2 513. The C – Cl bond in vinyl chloride is ............. and ............. compound to C – Cl bond in ethyl chloride 1) longer, weaker 2) shorter, weaker 3) longer, stronger 4) shorter, stronger Passage : Covalent compounds formed when two halogens react are termed interhalogen compounds. The actual product obtained depend on the relative concentrations of the halogens reacting. The reaction of the interhalogen compounds are generally not largely different from those of the halogens. Type X-Y compounds resemble the free halogen. But as the X-Y bond is weaker than the Y-Y bond hence X-Y compounds are generally more reactive than the Y2 molecule. 514. It is known that CI 2 reacts with water to form HCI and HOCI. So when ICI hydrolysed then 1) Only HCI is formed 2) Only HI is formed. 3) HOCI and HI are formed 4) HOI and HCI are formed. 515. What all the products formed when BrF5 is reacted with NaOH ? 1) NaFO3 and NaBr formed.

2) NaBrO3 and NaF are formed.

3) NaF and NaBr are formed. 4) NaBrF is formed along with F2 516. Iodine pentoxide on heating with dry HCI gives. a) ICI 3 correct code. 1) 1, 2 Passage – II :

b) CI 2

c) ICI 5

d) ICI

2) 1, 3

3) 1, 2, 3, 4

4) 1, 2, 3

According to molecular orbital theory all atomic orbitals combine to form molecular orbital by LCAO (Linear combination of atomic orbitals) method. When two atomic orbitals have additive (constructive) overlapping, they form bonding molecular orbitals (BMO) which have lower energy than atomic orbitals whereas when atomic orbitals overlap subtractively, higher energy antibonding molecular orbitals (AMO) are formed. Each M.O. occupies two electrons with opposite spin. Distribution of electron in M.O. follows Aufbau principle as well as Hund’s rule. M.O. theory can successfully explain magnetic behaviour of molecules. 517. Which of the following is/are not paramagnetic? 1) NO 2) B2 3) CO 4) O2

518. Bond strength increases when 1) bond order increases 3) antibonding electrons increases 519. O22- will have 1) bond order equal to H2 and diamagnetic 3) bond order equal to N2 and diamagnetic Passage – II

2) bond length increases 4) bond angle increases 2) bond order equal to H2 but paramagnetic 4) bond order higher than O2

According to molecular orbital theory when a pair of atomic orbitals combine they give rise to a pair of molecular orbitals. The number of molecular orbitals produced must always be equal to the number of atomic orbitals involved. The overlapping of orbitals means the overlapping of the wave of electron. Wave can overlap with in the same phase or in the opposite phase e.g.,

Bonding molecular orbitals

Antibonding molecular orbital

520. Which of the following combination gives bonding molecular orbitals? a) Y A - Y B b) Y A + Y B c) Y 2A - Y 2B 521. Which of the following is bonding molecular orbital? a)

d) Y A ´Y B

b)

c) Both of these d) None of these 522. The probability of finding the electrons in bonding molecular orbital equal to a) Y 2A + Y 2B

b) Y 2A + Y 2B - 2 Y A Y B c) Y 2A + Y 2B + 2Y A Y B d) None of these

Passage – II : When hybridisation involving d-orbitals are considered then all the five d-orbitals are not degenerate, rather d x 2- y 2 , d z 2 and d xy , d yz , d zx form two different sets of orbitals and orbitals of appropriate set is involved in the hybridisation 523. In sp3d2 hybridisation, which sets of d-orbitals is involved? 1) d x 2- y 2 , d z 2

2) d z 2 , d xy

3) d xy , d yz

4) d x 2- y 2 , d xy

524. In sp3d3 hybridisation, which orbitals are involved? 1) d x 2- y 2 , d z 2 , d xy

2) d xy , d yz , d zx

3) d x 2- y 2 , d xy , d xz

4) d z 2 , d yz , d zx

525. Molecule having trigonal bipyramidal geometry and sp3d hybridisation, d-orbitals involved is :

1) dxy

2) dyz

3) d x 2- y 2

4) d z 2

Passage – II : Covalent molecules formed by heteroatoms bound to have some ionic character. The ionic character is due to shifting of the electron pair towards A or B in the molecule AB. Hence, atoms acquire small and equal charge but opposite in sign. Such a bond which has some ionic character is described as polar covalent bond. Polar covalent molecules can exhibit dipole moment. Dipole moment is eual to the product of charge separation, q and the bond length, ‘d’ for the bond. The unit of dipole moment is Debye. One Debye is equal to 10–18 esu cm. Dipole moment is a vector quantity. It has both magnitude and direction. Hence, dipole moment of molecules depends upon the relative orientation of the bond dipoles, but not on the polarity of bonds alone. A symmetrical structure shows zero dipole moment. Thus, dipole moments help to predict the geometry of the molecules. Dipole moment values can be used to distinguish between cis-and transisomers; ortho-, meta- and para-forms of a substance, etc. The percentage of ionic character of a bond can be calculated by the application of the following formula : % ionic character =

Experimental value of dipole moment ´100 Theoretical value of dipole moment

526. Which are non-polar molecules? 1) XeF4 2) SF4

3) NH3

4) H2O

527. A diatomic molecule has a dipole moment of 1.2 D. If the bond length is 1.0 ´ 10–8 cm, what fraction of charge does exist on each atom? 1) 0.1 2) 0.2 3) 0.25 4) 0.3 528. The dipole moment of NF3 is very much less than that of NH3 because : 1) number of lone pairs in NF3 is much greater than in NH3 2) unshared electron pair is not present in NF3 as in NH3 3) both have different shapes 4) of different directrions of moments of N – H and N – F bonds Passage - II: Ionic compounds are soluble in water. They divided into ions in water and they are hydrated with water molecules. In solid state ionic compounds exhibit different crystal lattice structures like BCC, FCC, HCB etc. In these structures each cation surrounds with some anions and viceverse. The structure of ionic lattice can be determine by knowing co-ordination member. 529. The unit cell of NaCl contains 1) 4Na+ and 4Cl– ions 2) 3Na+ and 4Cl– ions 3) 4Na+ and 3Cl– ions 4) 2Na+ and 2Cl– ions 530. Dielectric constant of some solvents are respectively A = 25, B = 40, C = 55, D = 85. Then NaCl is highly soluble in 1) A 2) B 3) C 4) D 531. The limiting radius ratio of anionic compound is 0.93. Then the structure of ionic compound is 1) Tetrahedral 2) Octahedral 3) BCC 4) FCC Passage – II 0 The platinum-chlorine distance has been found to be 2.32 A in several crystalline compounds. This value applies to both of the compounds shown in figure.

Based on the above structures, answer the following questions: 532.

Cl – Cl distance in structure (A) is 3) 1.16 A0

4) 9.28 A0

533.

1) 2.32 A0 2) 4.64 A0 Cl – Cl distance in structure (B) is 1) 2.32 A0 A is 1) cis-isomer

2) 1.52 A0

3) 2.15 A0

4) 3.28 A0

2) trans-isomer

3) chiral isomer

4) none of these

534.

Paragraph : Thiourea S, S-dioxide O2SC(NH2)2 has the following skeletal structure

Based on the valence shell electron pair repulsion (VSEPR) model, predict geometries 535. What is the geometry around the sulphur atom? a) Trigonal pyramidal b) Triangular planar c) T-shape 536. What is the geometry around the carbon atom a) Trigonal pyramidal b) Triangular planar c) T-shape 537. What is the geometry around the N-atom? a) Trigonal pyramidal b) Triangular planar c) T-shape

d) irregular tetrahedral d) irregular tetrahedral d) irregular tetrahedral

Passage - I: The shapes of molecules can be predicted by VSEPR theory, hybridization and dipole moment. There is a high degree of correlation between hybridization and shapes of molecules or the inter orbital bond angles. If any depature in geometry of a molecule is observed on the basis of VSEPR theory then an apparent depature is observed in hybridisation. The types of hybridisation associated with various shapes are sp-linear; sp2-trigonal; sp3-tetrahedral. In case of the departure observed the most easy way is following relationship. For s.p hybridisation we have sp i hybrid is characterised by fs =

f 1 i or f p = and i = p i +1 i +1 fs

(in case of sp3, the value of i = 3 and for sp2 it is 2) also for any orbital, f s + f p = 1 and all s, p hybrids of a given atom å f s = 1.00 must be satisfied. For finding the inter-orbital angle between two equivalent (same fs and same fp) hybrid orbitals use the relation -1 i To predict the geometrical shape of species containing only one central atom use the following method. cos q =

(i) Total number of electron pairs =

(number of valence electrons ) ±(total ch arg e) 2

(ii) Number of bond electrons = (number of atom – 1) (iii) Number of electron pairs around central atom = [total number of electron pairs – 3 (number of terminal atoms except hydrogen)] iv) Number of lone pairs = [(number of central electron pairs) – (number of bond pairs)]

æ .. ö÷ çç ÷ H O H O 538. If we consider a molecule of 2 ç ..- H ø÷÷÷ , we find that it consists of two bond pairs and two ççè lone pairs. It was expected to be tetrahedral with bond angle 109.50 but it is V-shaped and has bond angle of 104.50. From this predict the oxygen hybrids used in O – H. The oxygen hybrid used are 1) sp3 2) sp4 3) sp5 4) sp2 8 539. The hybridization of P in PO43- is the same as that of 1) N in NO32) S in SO3 3) I in ICl2+ 4) I in ICl4540. Select the molecules that contain non-bonding electrons on the central atom 1) ICl3 2) ICl3 and SF4 3) SF4 and SO2 4) ICl3, SF4 and SO2 Passage – I : Lewis concept of covalency of an element involved octet rule. Later on it was found that may elements in their compounds e.g. BeF2, BF3 etc. have incomplete octet whereas PCl5, SF6 etc. have expanded octet. This classical concept also failed in predicting the geometry of molecules. Modern concept of covalence was proposed in terms of valence bond theory. Hybridization concept along with V.B. Theory successfully explained the geometry of various molecules but failed in many molecules. The geometry of such molecules was explained by VSEPR concept. Finally molecular orbital theory was proposed to explain many other molecules 541. Which are true statements among the following? I) I 3- has bent structure

II) pp – pp bonds are present in SO2

III) SeF4 and CH4 has same shape IV) XeF2 and CO2 has same shape V) SF4 is sea-saw structure whereas lCl3 is T-shaped 1) I, II, IV, V 2) I, II, III, IV 3) II, III, IV, V 4) I, III, IV, V 542. The bond angles NO2+ , NO2 and NO2- are respectively 1) 1800, 1340, 1150

2) 1150, 1340, 1800

3) 1340, 1800, 1150

4) 1150, 1800, 1300

543. Which statements are correct CO+ and N 2+ according to M.O theory I) Both have same configuration

II) Bond order for CO+ and N 2+ are 3.5 and 2.5

III) Bond order of CO+ and N 2+ are same IV) During the formation of N 2+ from N2 bond length increases V) During the formation of CO+ from CO, the bond length decreases 1) II, IV, V 2) I, III, IV, V 3) I, III Matching type question: 601. List – I

4) I, II, III

List – II

a) ICl2-

p) Linear

b) BrF2+

q) Pyramidal

c) ClF4-

r) Tetrahedral

d) AlCl4-

s) Square planar t) Angular

602. Match the hybridization of central atom and geometry described in List II with the species in List I : List - I

List - II

a) XeF4

p) sp3d ,see-saw geometry

b) SF4

q) sp 3d 2 , square planar

c) SF6

r) sp 3d 2 , distorted octahedral geometry

d) XeF6

s) sp 3d 2 , octahedral geometry

603. Match the following Column – I with Column – II Column – I Compound Column – I (Hybridisation of the central atom) a) SO3 p) sp b) I 3-

q) sp2

c) CO2

r) sp3

d) PO4-3 604. Column – I a) O2 molecule b) CO molecule c) KO2 molecule c) NO2 molecule 605. Column – I a) PBr3Cl2

s) sp3d Column – II p) Paramagnetic q) On unpaired electron r) Bond order equal to N2 s) Angular Column – II p) Symmetric molecule

b)

q) Assymmetrical structure

c) PCl3Br2 r) Non zero dipole moment d) BF3 molecule s) Zero dipole moment 606. Match the following Column – I with Column – II Column – I

Column – II

a) SiO32– b) BF3

p) Planar triangular q) Non Polar

c) CO32-

r) Bond order 1.33

d) NO3s) Resonance hybrid of three structure 607. Match the following Column – I & Column – II Column – I Column – II a) Solid PF5 b) Solid PCl5 c) Gas PCl5 d) Gas PBr5

p) Square planar q) Trigonal bi-pyramid r) Tetrahedral s) Octahedral t) Trigonal planar

608. Match the following Column – I with Column – II Column – I Column – II Pair of species Identical property in pairs of species a) PCl3F2, PCl2F3 b) BF3 and BCl3

p) Hybridisation of central atom q) Shape of molecule/ion

c) CO2 and CN 2-2

r) m(dipole moment)

d) C6H6 and B3N3H6 609. Column – I

s) Total number of electrons Column – II

a) N 3-

p) Trigonal bipyramidal geometry

b) I 3c) O3

q) sp hybridization r) Formal charge on centre atom is + 1

d) ICl2Q

s) Linear

610. Match the molecular species in List – I with their shape in List – II Column - I

Column - II

a) Linear shape

p) CS2

b) sp hybridization c) sp3d hybridization d) CO2 is isostructural to 611.

List – I

q) XeF2 r) C2H2 s) NCO– List – II

a) Ionic bonds b) Covalent bonds c) Metallic bonds d) Coordinate bonds 612. Match the followinng : List – I a) BF3 b) SO2 c) SO3

p) NH4Cl q) Non directional r) Diamond s) Gadolinium

d) CO32 613. Column - I (Decreasing order)

s) Planar triangular

614.

615.

p) Dipolemement q) Melting point r) Enthalpies of vaporisation

d) H2O H2Te H2Se H2S

s) Boiling point

List – I

618.

List – II

a) NaCl molecule b) H – Cl molecule c) I – Cl molecule

p) Tetrahedral molecule q) More reactive than chlorine r) Non-directonal bonds

d) ClO4- ion

s) Polar covalent bonds

List – I

List – I a) O2 molecule b) CO molecule c) KO2 molecule d) NO2 molecule

617.

Column - II (Physical properties

a) NH3, SbH3, AsH3, PH3 b) HF HCl HBr HI c) SnH4 GeH4 SiH4 CH4

a) ClF3 molecule is T-shaped b) Bond order of O3 c) Carbonate ion stabilized d) CO2 is symmetrical 616.

List – II p) sp2 hybridisation q) Bond angle 1200 r) One lone pair

List – I

List – II p) Dipolemoment q) Similar to benzene r) VSEPR theory s) Resonance theory List – II p) Paramagnetic q) One unpaird electron r) Bond order equal to N2 s) Angular List – II

a) Bond order of NO3-

p) 2

b) Bond order of SO2 c) Bond order O3 d) Bond order CO2

q) Equal to bond order to benzene r) 1.33 s) 1.5

List – I a) N2, NH3, O2

List – II p) Paramagnetic

CHEMISTRY – Chemical bonding IIT Questions KEY (11-11-11)

Single ans: 1. 2

2. 4

3. 4

4. 4

5. 4

6. 1

7. 2

8. 3

9.1

10. 2

11. 3

12. 4

13. 4

14. 2

15. 4

16. 2

17. 2

18. 2

19. 3

20. 1

21. 1

22. 4

23.

24.

25.

26.

27.

28.

29.

30.

31.

32.

33.

34.

35.

36.

37.

38.

39.

40.

41.

42.

43.

44. 2

45. 2

46. 2

47. 2

48. 2

49. 1

50. 4

51.

52.

53.

54.

55.

56.

57.

58.

59.

60.

61.

62.

64.

65.

66.

67.

68.

69.

70.

71.

72.

63 . 73. 3

74.1

75. 2

76. 2

77. 1

78. 3

79. 2

80. 2

81.3

82.2

83.

84 .

85.2

86.2

87.1

88. 3

89. 1

90. 4

91. 2

92. 3

93. 3

94. 3

95.2

96.4

97. 4

98. 4

99. 2

100. 2

101.1

102.

103.

104.2

105.1

106.2 107.3

108.1

109.4

110.1

111.1

112.1

113. 1

114.3

115.4

116.3 117.4

118.4

119.c 120.b

121.

122.4

123.3

124.3

125.4

126.4 127.2

128.2

129.3

130.3

131.1

132.4

133.2

134.4

135.1

136.1 137.

138.

139.

140.

141.

142.

143.

144.

145.

146.

148.

149.

150.

151.

152.

153.

154.

155.

156.3 1571,3,4

158.1

159.4

160.3

161.3

162.2

163.

164.

165.4

166.2 167.3

168.3

169. 3 170. 3

171.

172.2

173. 3

174.3

175 .3

176.2 177.

178.

179.

180.

181.

182.

183.

184.

185.

186.

187.

188.

189.

190.

191.

192.

193.

194.

195.

196.

197.2

198.

199.

200.

201.

202.

203.b

204.2

205.1

206.2 207. 1

208. 3

209. 2 210. 1, 2,

3, 4

211.

212. 1

213. 1

214. 2

215. 4

305.

306.

307.3

308. 4 309.1

310 .3

147.

A&R 301.

302.

303. 1

304. 3

311.2

312.1

313.2

314.2

315.1

316.1

317.4

318. 2

319. 2

320.3

321.2

322.2

323.3

324.1

325.

326.

327. 1

328. 4

329. 2

330.

331.

332.

404.

405.

406.

407.

408.

409.

410.

414.1,2

415.1,2,3,4 416.2,3,4

417.3,4

422.1,2

423,1,2

424.2,3,4

425.1,2,3,4

429.1,3 430.2,4

431.1,4

One or more: 401.

402.

403.

411.

412.

413.1,2,3

418.1,4

419.

420.

421.

426. 1,2,4

427. 1,3,4

432.1,2,4

433.

434.1,3,4

428.1,2,3,4

435.1,2,3,4 436. 2,3,4

437.1,2,3

438.1,2

439.1

440.1,2,3,4

441.

442.1,2,3

443.1,2,3

444.1,3

445.

446.

447.

448.

449.

450.

451.

452.1,3,4

453.1, 2, 3, 4

455. 1, 2, 4

456. 4

457. 1, 3 458. 2, 3

459. 2, 3, 4

460. 2, 4

461. 1, 3

Passage: 501.

502.

503.

504.

505.

506.

507.

508.

509.

510.

511. 2

512. 3

513. 4

514.

515.

516.

517. 3

518. 1

519. 1

520. b

521. b

522. c

523. 1

524. 1

525. 4

526.1

527.3

528.4

529. 1

530. 4

531. 3

532.

533.

534.

535.b

536.b

537.a

538.2

539.3

540.4

541.

542.

543.

Matching: 601.a – p; b – t; c – s; d – r 602. 603. 604.a – p; b – r; c – p, q; d – q, s 605.a – p, s; b – p, r; c – q, r; d – p, s 606.a – p, q, r, s; b – p, q, r, s; c – p, q, r, s; d – p, q, r, s 607.a – q; b – r, s; c – q; d – q

608.a – p, q; b – p, q, r; c – p, q, r, s; d – p, q, r, s

609.a – q, r, s; b – p, r, s; c – r; d – p, r, s

610.a – p, q, r, s; b – p, r, s; c – q; d – p

611.a – p, q; b – q; c – s; d – r 612.a – p, q, s; b – p, r; c – p, q, s; d – p, q, s

613.a – q, r; b – p; c – r, s; d – q, r, s

614. a – r; b – q, s; c – q, s; d – p 615.a – r; b – q, s; c – s; d – p

616. a – p; b – r; c – p, q; d – q, s

617.a – r; b – q, s; c – q, s; d – p

618. a – p, q, r; b – q; c – p; d – s

619.a – p, q, s; b – p, s; c – p, r; d – p, q, r, s

620.a – p, s; b – r; c – p, q; d – p

621.A - p B - r C - q D - add 622.a – p, q, r, s; b – p, q, r; c – p, q; d – q, t

623.

624.a – r; b – p, s; c – s; d – q, s

625.a – q, r; b – q, r; c – p, s; d – p, s

Numerical: 701.2

702.0

703. 4

704.5

705.8

706.4 707.8

708.1

709.8

710.8