VSEPR Theory CSIR NET CHEMICAL SCIENCE

Q: What is the primary difference between electron geometry and molecular shape?

Electron geometry describes the spatial arrangement of all electron pairs (both bonding pairs and non-bonding lone pairs) surrounding the central atom. Molecular shape describes only the relative positions of the bonded atomic nuclei.

Q: Why does H2O have a smaller bond angle (104.5 degrees) than NH3 (107 degrees)?

Both molecules have a tetrahedral electron geometry (SN = 4). However, H2O has two lone pairs on oxygen, whereas NH3 has only one lone pair on nitrogen. Because lp-lp repulsion is stronger than lp-bp repulsion, the two lone pairs in water compress the H-O-H bond angle significantly more.

Q: What is Drago's Rule and when does VSEPR theory fail?

Drago's Rule states that if the central atom belongs to the 3rd period or lower, has at least one lone pair, and is bonded to atoms with electronegativity <= 2.5 (e.g., H in PH3, H2S), hybridization does not take place. Bonding occurs through nearly pure p-orbitals, resulting in bond angles close to 90 degrees.

Question 1

Among SF4, BF4−, XeF4 and ICl4− the number of species having two lone pair of electrons on the central atom according to VSEPR theory is:

Accepted Answer

2

Answer

3

Answer

4

Question 2

In the molecules H2O, NH3 and CH4:

Accepted Answer

The hybridizations are same (संकरण समान हैं)

Answer

The bond angles are same (बंध कोण समान हैं)

Answer

The bond distances are same (बंध दूरियां समान हैं)

Answer

The shapes are same (आकृतियां समान हैं)

Question 3

The total number of lone pairs of electrons in I3− is:

Accepted Answer

Nine (नौ)

Answer

Zero (शून्य)

Answer

Three (तीन)

Answer

Six (छह)

Question 4

Which ones among CO32−, SO3, XeO3 and NO3− have planar structure?

Accepted Answer

CO32−, SO3, and NO3−

Answer

CO32−, SO3 and XeO3

Answer

SO3, XeO3, and NO3−

Answer

CO32−, XeO3, and NO3−

Question 5

The number of lone-pairs are identical in the pairs:

Accepted Answer

XeF4, ClF3

Answer

XeO4, ICl4−

Answer

XeO2F2, ICl4−

Answer

XeO4, ClF3

Question 6

According to VSEPR theory, the geometry (with lone pair) around the central iodine in I3+ and I3− ions respectively are:

Accepted Answer

tetrahedral and trigonal bipyramidal (चतुष्फलकीय तथा त्रिकोणीय द्विपिरामिडी)

Answer

tetrahedral and tetrahedral (चतुष्फलकीय तथा चतुष्फलकीय)

Answer

trigonal bipyramidal and trigonal bipyramidal (त्रिकोणीय द्विपिरामिडी तथा त्रिकोणीय द्विपिरामिडी)

Answer

tetrahedral and octahedral (चतुष्फलकीय तथा अष्टफलकीय)

Question 7

The structure of SbPh5 and PPh5 respectively are:

Accepted Answer

square pyramidal, trigonal bipyramidal (वर्ग पिरामिडी, त्रिकोणीय द्विपिरामिडी)

Answer

trigonal bipyramidal, square pyramidal (त्रिकोणीय द्विपिरामिडी, वर्ग पिरामिडी)

Answer

trigonal bipyramidal, trigonal bipyramidal (त्रिकोणीय द्विपिरामिडी, त्रिकोणीय द्विपिरामिडी)

Answer

square pyramidal, square pyramidal (वर्ग पिरामिडी, वर्ग पिरामिडी)

Question 8

The correct non-linear and iso-structural pair is:

Accepted Answer

SCl2, I3+

Answer

SCl2, I3−

Answer

SCl2, ClF2−

Answer

I3+, ClF2−

Question 9

The structure of XeF2 and XeO2F2 respectively are:

Accepted Answer

linear, see-saw (रैखिक, सी-सॉ / ढेंकुली)

Answer

bent, tetrahedral (कोणीय, चतुष्फलकीय)

Answer

linear, square planar (रैखिक, वर्ग समतलीय)

Answer

bent, see-saw (कोणीय, सी-सॉ)

Question 10

The correct shape of [TeF5]− ion on the basis of VSEPR theory is:

Accepted Answer

Square pyramidal (वर्ग पिरामिडी)

Answer

Trigonal bipyramidal (त्रिकोणीय द्विपिरामिडी)

Answer

Pentagonal planar (पंचकोणीय समतलीय)

Answer

See-saw (सी-सॉ)

Question 11

The expected H−H−H bond angle in [H3]+ is:

Accepted Answer

60°

Answer

180°

Answer

120°

Answer

90°

Question 12

Based on VSEPR theory, the predicted shapes of [XeF5]− and BrF5 respectively, are:

Accepted Answer

pentagonal planar and square pyramidal (पंचकोणीय समतलीय तथा वर्ग पिरामिडी)

Answer

square pyramidal and trigonal bipyramidal (वर्ग पिरामिडी तथा त्रिकोणीय द्विपिरामिडी)

Answer

trigonal bipyramidal and square pyramidal (त्रिकोणीय द्विपिरामिडी तथा वर्ग पिरामिडी)

Answer

square pyramidal and pentagonal planar (वर्ग पिरामिडी तथा पंचकोणीय समतलीय)

Question 13

Among ClO3−, XeO3 and SO3, species with pyramidal shape is/are?

Accepted Answer

ClO3− and XeO3

Answer

XeO3 and SO3

Answer

ClO3− and SO3

Answer

SO3

Question 14

Geometries of SNF3 and XeF2O2, respectively, are:

Accepted Answer

tetrahedral and trigonal bipyramidal (चतुष्फलकीय तथा त्रिकोणीय द्विपिरामिडी)

Answer

square planar and square planar (वर्ग समतलीय तथा वर्ग समतलीय)

Answer

tetrahedral and tetrahedral (चतुष्फलकीय तथा चतुष्फलकीय)

Answer

square planar and trigonal bipyramidal (वर्ग समतलीय तथा त्रिकोणीय द्विपिरामिडी)

Question 15

Boron in BCl3 has:

Accepted Answer

sp2 hybridization (sp2 संकरण)

Answer

sp hybridization (sp संकरण)

Answer

sp3 hybridization (sp3 संकरण)

Answer

no hybridization (कोई संकरण नहीं)

Question 16

Among SiCl4, P(O)Cl3, NF3, trans-[SnCl4(py)2] (py = pyridine), those with zero dipole moment are:

Accepted Answer

SiCl4 and trans-SnCl4(py)2

Answer

SiCl4 and NF3

Answer

SiCl4, P(O)Cl3 and trans-SnCl4(py)2

Answer

NF3 and trans-SnCl4(py)2

Question 17

The magnitude of bond angles in gaseous NF3, SbF3 and SbCl3 follow the order:

Accepted Answer

NF3 > SbCl3 > SbF3

Answer

NF3 > SbF3 > SbCl3

Answer

SbCl3 > SbF3 > NF3

Answer

SbF3 > SbCl3 > NF3

Question 18

Among the following which set of molecular/ionic species all have the planar structure?

Accepted Answer

[ClF4]−, BrF3, and [XeF5]−

Answer

BrF3, FClO2 and [XeF5]−

Answer

XeO3, [ClF4]− and FClO2

Answer

FClO2, [XeF5]− and XeO3

Question 19

The shape of the molecule XeO2F2 is:

Accepted Answer

trigonal bipyramidal (त्रिकोणीय द्विपिरामिडी)

Answer

distorted octahedral (विकृत अष्टफलकीय)

Answer

square planar (वर्ग समतलीय)

Answer

tetrahedral (चतुष्फलकीय)

Question 20

[XeO6]4− is octahedral whereas XeF6 is a distorted one, because:

Accepted Answer

Xe has a lone-pair in XeF6 (XeF6 में Xe पर एक एकाकी युग्म है)

Answer

fluorine is more electronegative than oxygen (फ्लोरीन ऑक्सीजन से अधिक विद्युतऋणात्मक है)

Answer

XeF6 is neutral whereas [XeO6]4− is anionic (XeF6 उदासीन है जबकि [XeO6]4− ऋणायनिक है)

Answer

Xe−F has more ionic character (Xe−F में अधिक आयनिक लक्षण है)

Question 21

The pair of compounds having the same hybridization for the central atom is:

Accepted Answer

XeF4 and [SiF6]2−

Answer

[NiCl4]2− and [PtCl4]2−

Answer

Ni(CO)4 and XeO2F2

Answer

[Co(NH3)6]3+ and [Co(H2O)6]3+

Question 22

If ClF3, were to be stereochemically rigid, its 19F NMR spectrum (I for 19F = 1/2, assume that Cl is not NMR active) would be (assume that Cl is not NMR active):

Accepted Answer

a doublet and a triplet (एक डबलेट तथा एक ट्रिपलेट)

Answer

a singlet (एक सिंगलेट)

Answer

a doublet and a singlet (एक डबलेट तथा एक सिंगलेट)

Answer

two singlets (दो सिंगलेट)

Question 23

The geometry around the central atom in ClF4+ is:

Accepted Answer

trigonal bipyramidal (त्रिकोणीय द्विपिरामिडी)

Answer

square planar (वर्ग समतलीय)

Answer

square pyramidal (वर्ग पिरामिडी)

Answer

octahedral (अष्टफलकीय)

Question 24

Among the following, the isoelectronic and isostructural pair is:

Accepted Answer

SiO44− and PO43−

Answer

CO2 and SO2

Answer

SO3 and SeO3

Answer

NO2+ and TeO2

Question 25

According to VSEPR model, the shape of [XeOF5]− is:

Accepted Answer

pentagonal monopyramidal (पंचकोणीय एकपिरामिडी)

Answer

octahedral (अष्टफलकीय)

Answer

trigonal bipyramidal (त्रिकोणीय द्विपिरामिडी)

Answer

square pyramidal (वर्ग पिरामिडी)

Question 26

Among the following, the group of molecules that undergoes rapid hydrolysis is:

Accepted Answer

BCl3, SiCl4, PCl5

Answer

SF6, Al2Cl6, SiMe4

Answer

BCl3, SF6, SiCl4

Answer

SF6, Al2Cl6, SiCl4

Question 27

The reaction of solid XeF2 with AsF5 in 1: 1 ratio affords:

Accepted Answer

[XeF]+[AsF6]−

Answer

XeF4 and AsF3

Answer

XeF6 and AsF3

Answer

[Xe2F3]+[AsF6]−

Question 28

According to VSEPR theory, the shape of [SF2Cl]+ and [S2O4]2− should be:

Accepted Answer

trigonal planar for [S2O4]2− and trigonal pyramidal for [SF2Cl]+

Answer

both are trigonal planar (दोनों त्रिकोणीय समतलीय हैं)

Answer

trigonal pyramidal for [S2O4]2− and trigonal planar for [SF2Cl]+

Answer

both trigonal pyramidal (दोनों त्रिकोणीय पिरामिडी हैं)

Question 29

The order of polarity of NH3, NF3 and BF3 is:

Accepted Answer

BF3 < NF3 < NH3

Answer

NF3 < NH3 < BF3

Answer

BF3 < NH3 < NF3

Answer

NF3 < BF3 < NH3

Question 30

Conversion of boron trifluoride to tetrafluoroborate accompanies:

Accepted Answer

increase in symmetry and bond elongation (सममिति में वृद्धि तथा बंध दीर्घीकरण)

Answer

increase in symmetry and bond contraction (सममिति में वृद्धि तथा बंध संकुचन)

Answer

decrease in symmetry and bond contraction (सममिति में कमी तथा बंध संकुचन)

Answer

decrease in symmetry and bond elongation (सममिति में कमी तथा बंध दीर्घीकरण)

Question 31

The shapes of XeF5+ and XeF5−, respectively, are:

Accepted Answer

square pyramidal and pentagonal planar (वर्ग पिरामिडी तथा पंचकोणीय समतलीय)

Answer

pentagonal planar and square pyramidal (पंचकोणीय समतलीय तथा वर्ग पिरामिडी)

Answer

pentagonal planar and trigonal bipyramidal (पंचकोणीय समतलीय तथा त्रिकोणीय द्विपिरामिडी)

Answer

square pyramidal and pentagonal bipyramidal (वर्ग पिरामिडी तथा पंचकोणीय द्विपिरामिडी)

Question 32

Among the following species, the one that has pentagonal shape is:(Given: atomic numbers of O, F, S, I and Xe are 8, 9, 16, 53 and 54, respectively)

Accepted Answer

[XeF5]−

Answer

XeOF4

Answer

IF5

Answer

[SF5]−

Question 33

The shapes of the compounds ClF3, XeOF2, N3− and XeO3F2 respectively, are:

Accepted Answer

T-shape, T-shape, linear and trigonal bipyramidal

Answer

trigonal planar, T-shape, V-shape and square pyramidal

Answer

T-shape, trigonal planar, linear, and square pyramidal

Answer

trigonal planar, trigonal planar, V-shape and trigonal bipyramidal

Question 34

According to VSEPR theory, the molecule/ion having ideal tetrahedral shape is:

Accepted Answer

SO42−

Answer

SF4

Answer

S2Cl2

Answer

SO2Cl2

Question 35

The molecule with highest number of lone-pairs and has a linear shape based on VSEPR theory is:

Accepted Answer

I3−

Answer

CO2

Answer

NO2−

Answer

NO2+

Question 36

Match list I (compounds) with list II (structures), and select the correct answer using the codes given below:List I (Compound)List II (Structure)(A) XeO4(i) square planar(B) BrF4−(ii) tetrahedral(C) SeCl4(iii) distorted tetrahedral

Accepted Answer

(A–ii) (B–i) (C–iii)

Answer

(A–ii) (B–iii) (C–i)

Answer

(A–iii) (B–i) (C–ii)

Answer

(A–i) (B–ii) (C–iii)

Question 37

Among the following pairs, those in which both species have similar structures are:(A) N3−, XeF2(B) [ICl4]−, [PtCl4]2−(C) [ClF2]+, [ICl2]−(D) XeO3, SO3

Accepted Answer

(A) and (B) only

Answer

(A) and (C) only

Answer

(A), (B) and (C) only

Answer

(B), (C) and (D) only

Question 38

The decreasing order of dipole moment of molecules is:

Accepted Answer

H2O > NH3 > NF3

Answer

NF3 > NH3 > H2O

Answer

NH3 > NF3 > H2O

Answer

H2O > NF3 > NH3

Question 39

The geometries of [Br3]+ and [I5]+, respectively, are:

Accepted Answer

tetrahedral and trigonal bipyramidal (चतुष्फलकीय तथा त्रिकोणीय द्विपिरामिडी)

Answer

trigonal and tetrahedral (त्रिकोणीय तथा चतुष्फलकीय)

Answer

tetrahedral and tetrahedral (चतुष्फलकीय तथा चतुष्फलकीय)

Answer

linear and trigonal pyramidal (रैखिक तथा त्रिकोणीय पिरामिडी)

Question 40

The number of lone pair(s) of electrons on the central atom in [BrF4]−, XeF6 and [SbCl6]3− are, respectively:

Accepted Answer

2, 1 and 1

Answer

2, 0 and 1

Answer

1, 0 and 0

Answer

2, 1 and 0

Question 41

Choose the correct option for carbonyl fluoride with respect to bond angle and bond length:

Accepted Answer

∠F−C−F < ∠F−C−O and C−F > C−O

Answer

∠F−C−F > ∠F−C−O and C−F > C−O

Answer

∠F−C−F > ∠F−C−O and C−F < C−O

Answer

∠F−C−F < ∠F−C−O and C−F < C−O

Question 42

According to Bent’s rule, for p-block elements, the correct combination of geometry around the central atom and position of more electronegative substituent is:

Accepted Answer

Trigonal bipyramidal and axial (त्रिकोणीय द्विपिरामिडी तथा अक्षीय)

Answer

Trigonal bipyramidal and equatorial (त्रिकोणीय द्विपिरामिडी तथा निरक्षीय)

Answer

Square pyramidal and axial (वर्ग पिरामिडी तथा अक्षीय)

Answer

Square pyramidal and basal (वर्ग पिरामिडी तथा आधारीय)

Question 43

Match the appropriate geometry on the right with each of the species on the left:SpeciesGeometry(A) FXeO(OSO2F)(i) linear(B) FXeN(SO2F)2(ii) pyramidal(C) XeO3(iii) T-Shaped(D) XeOF2(iv) bent

Accepted Answer

(A)-(i),(B)-(i),(C)-(ii),(D)-(iii)

Answer

(A)-(i),(B)-(i),(C)-(ii),(D)-(iv)

Answer

(A)-(iv),(B)-(i),(C)-(ii),(D)-(iii)

Answer

(A)-(i),(B)-(iv),(C)-(ii),(D)-(iii)

Question 44

The species for which the shapes (geometry) can be predicted by VSEPR theory is/are:(A) [PtCl4]2−(B) [TeCl6]2−(C) PF3 and SF6Answer is:

Accepted Answer

C only

Answer

A and C

Answer

B and C

Answer

A and B

Question 45

As per the VSEPR theory, shapes of SO32−, CO32− and BrF4− are, respectively:

Accepted Answer

Trigonal pyramidal, trigonal planar and square planar (त्रिकोणीय पिरामिडी, त्रिकोणीय समतलीय तथा वर्ग समतलीय)

Answer

Trigonal pyramidal, trigonal planar and tetrahedral (त्रिकोणीय पिरामिडी, त्रिकोणीय समतलीय तथा चतुष्फलकीय)

Answer

Trigonal planar, trigonal pyramidal and square planar (त्रिकोणीय समतलीय, त्रिकोणीय पिरामिडी तथा वर्ग समतलीय)

Answer

Trigonal planar, trigonal pyramidal and tetrahedral (त्रिकोणीय समतलीय, त्रिकोणीय पिरामिडी तथा चतुष्फलकीय)

Steric No. (SN)	Bond Pairs (bp)	Lone Pairs (lp)	Electron Geometry	Molecular Shape	Ideal / Actual Angles	Classic Examples
2	2	0	Linear	Linear	180°	BeCl₂, CO₂, HCN
3	3	0	Trigonal Planar	Trigonal Planar	120°	BF₃, SO₃, NO₃⁻
3	2	1	Trigonal Planar	Bent / V-shaped	< 120° (≈ 119°)	SO₂, O₃, NO₂⁻
4	4	0	Tetrahedral	Tetrahedral	109.5°	CH₄, NH₄⁺, CCl₄
4	3	1	Tetrahedral	Trigonal Pyramidal	< 109.5° (≈ 107°)	NH₃, PCl₃, H₃O⁺
4	2	2	Tetrahedral	Bent / Angular	< 109.5° (≈ 104.5°)	H₂O, H₂S, OF₂
5	5	0	Trigonal Bipyramidal (TBP)	Trigonal Bipyramidal	120° (eq), 90° (ax)	PCl₅, PF₅
5	4	1	Trigonal Bipyramidal	See-Saw	< 120°, < 90°	SF₄, TeCl₄
5	3	2	Trigonal Bipyramidal	T-shaped	< 90° (≈ 87.5°)	ClF₃, BrF₃
5	2	3	Trigonal Bipyramidal	Linear	180°	XeF₂, I₃⁻, [ICl₂]⁻
6	6	0	Octahedral	Octahedral	90°	SF₆, [PF₆]⁻
6	5	1	Octahedral	Square Pyramidal	< 90°	BrF₅, IF₅, XeOF₄
6	4	2	Octahedral	Square Planar	90°, 180°	XeF₄, [ICl₄]⁻
7	7	0	Pentagonal Bipyramidal (PBP)	Pentagonal Bipyramidal	72° (eq), 90° (ax)	IF₇
7	5	2	Pentagonal Bipyramidal	Pentagonal Planar	72°	[XeF₅]⁻, [IF₅]²⁻

VSEPR Theory PYQ CBT Mock Test | Chemical Bonding Questions

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VSEPR Theory PYQs CBT Mock Test | Chemical Bonding

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📊 2. Master VSEPR Geometry vs. Molecular Shape Table (SN 2 to 7)

💻 Live CBT Mock Test: VSEPR Theory & Molecular Shapes

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