Chemical Bonding and Molecular Structure MCQs – Class 11
Chemical Bonding and Molecular Structure MCQs – Class 11 Chemistry
Course: CBSE Class 11 Chemistry – MCQs with Answers and Explanations
Section: Physical Chemistry – MCQ Titles
The following 50 MCQs are strictly based on the NCERT chapter “Chemical Bonding and Molecular Structure”. Questions are arranged section-wise to ensure complete syllabus coverage and include clear, concept-clearing explanations, making them ideal for CBSE Class 11 board exam preparation.
Section A: Kossel–Lewis Approach and Types of Chemical Bonds
1. Chemical bonding occurs mainly due to
A. attraction between nuclei
B. interaction of valence electrons
C. presence of neutrons
D. mass of atoms
Answer: B
Explanation: Chemical bonds are formed due to interactions between valence electrons of atoms.
2. Which type of bond is formed by transfer of electrons?
A. Covalent bond
B. Ionic bond
C. Hydrogen bond
D. Metallic bond
Answer: B
Explanation: Ionic bonds are formed by complete transfer of electrons from one atom to another.
3. Which compound shows ionic bonding?
A. H₂
B. Cl₂
C. NaCl
D. CH₄
Answer: C
Explanation: Sodium transfers an electron to chlorine forming Na⁺ and Cl⁻ ions.
4. Covalent bond is formed by
A. loss of electrons
B. gain of electrons
C. sharing of electrons
D. attraction of nuclei
Answer: C
Explanation: Covalent bonds involve sharing of electron pairs.
5. Which element usually does not form ionic bonds?
A. Sodium
B. Magnesium
C. Chlorine
D. Carbon
Answer: D
Explanation: Carbon prefers covalent bonding due to high ionization enthalpy.
Section B: Lewis Structures and Octet Rule
6. Lewis symbols represent
A. total electrons
B. valence electrons
C. core electrons
D. neutrons
Answer: B
Explanation: Lewis symbols show valence electrons as dots.
7. Octet rule states that atoms tend to achieve
A. 2 electrons
B. 4 electrons
C. 6 electrons
D. 8 electrons
Answer: D
Explanation: Atoms try to achieve noble gas configuration.
8. Which element does not obey octet rule?
A. Carbon
B. Oxygen
C. Hydrogen
D. Nitrogen
Answer: C
Explanation: Hydrogen follows duplet rule.
9. Expanded octet is observed in elements
A. of second period
B. of third period and beyond
C. of first period
D. noble gases only
Answer: B
Explanation: Elements like P and S can have more than eight electrons.
10. BF₃ does not follow octet rule because
A. boron has large size
B. boron has only 6 electrons
C. fluorine is highly electronegative
D. bond is ionic
Answer: B
Explanation: Boron forms an incomplete octet.
Section C: Formal Charge and Bond Parameters
11. Formal charge helps in
A. predicting shape
B. predicting stability of structure
C. calculating bond angle
D. finding polarity
Answer: B
Explanation: Structure with minimum formal charges is most stable.
12. Bond length depends on
A. atomic size only
B. bond order only
C. atomic size and bond order
D. electronegativity only
Answer: C
Explanation: Higher bond order means shorter bond length.
13. Bond energy is highest for
A. single bond
B. double bond
C. triple bond
D. hydrogen bond
Answer: C
Explanation: Triple bonds are strongest.
14. Which bond is longest?
A. C–C
B. C=C
C. C≡C
D. C–H
Answer: A
Explanation: Single bonds are longest.
15. Polar covalent bond is formed when
A. electronegativity difference is zero
B. electronegativity difference is large
C. electronegativity difference is moderate
D. electrons are transferred
Answer: C
Explanation: Moderate difference leads to unequal sharing.
Section D: VSEPR Theory and Molecular Shapes
16. VSEPR theory is based on
A. attraction between electrons
B. repulsion between electron pairs
C. repulsion between nuclei
D. bond energy
Answer: B
Explanation: Electron pairs repel and arrange to minimize repulsion.
17. Shape of BeCl₂ is
A. bent
B. trigonal planar
C. linear
D. tetrahedral
Answer: C
Explanation: Two bond pairs arrange linearly.
18. Shape of NH₃ is
A. tetrahedral
B. trigonal planar
C. trigonal pyramidal
D. bent
Answer: C
Explanation: One lone pair distorts tetrahedral shape.
19. Shape of H₂O is
A. linear
B. bent
C. trigonal planar
D. tetrahedral
Answer: B
Explanation: Two lone pairs cause bending.
20. Lone pair–lone pair repulsion is
A. weakest
B. same as bond pair
C. strongest
D. negligible
Answer: C
Explanation: Lone pairs occupy more space.
Section E: Valence Bond Theory and Hybridisation
21. Hybridisation involves
A. mixing of orbitals of same atom
B. mixing of orbitals of different atoms
C. mixing of electrons
D. mixing of shells
Answer: A
Explanation: Atomic orbitals of same atom combine.
22. Hybridisation in methane is
A. sp
B. sp²
C. sp³
D. dsp²
Answer: C
Explanation: Carbon forms four equivalent sp³ orbitals.
23. Hybridisation of carbon in ethene is
A. sp
B. sp²
C. sp³
D. dsp²
Answer: B
Explanation: One double bond requires sp² hybridisation.
24. Hybridisation in ethyne is
A. sp
B. sp²
C. sp³
D. dsp³
Answer: A
Explanation: Triple bond requires sp hybridisation.
25. Shape of sp hybridised molecules is
A. tetrahedral
B. trigonal planar
C. linear
D. bent
Answer: C
Explanation: sp hybrid orbitals arrange linearly.
Section F: Molecular Orbital Theory
26. Molecular orbital theory was proposed by
A. Bohr
B. Lewis
C. Hund and Mulliken
D. Pauling
Answer: C
Explanation: MOT explains bonding using molecular orbitals.
27. Bond order is defined as
A. number of bonds
B. difference between bonding and antibonding electrons ÷ 2
C. sum of electrons
D. total orbitals
Answer: B
Explanation: BO = (Nb − Na)/2.
28. A molecule with zero bond order is
A. stable
B. unstable
C. highly reactive
D. ionic
Answer: B
Explanation: Zero bond order means no bond formation.
29. Which molecule is paramagnetic?
A. H₂
B. N₂
C. O₂
D. F₂
Answer: C
Explanation: O₂ has unpaired electrons.
30. Bond order of N₂ is
A. 1
B. 2
C. 3
D. 4
Answer: C
Explanation: Triple bond exists in N₂.
Section G: Hydrogen Bonding
31. Hydrogen bonding occurs when hydrogen is bonded to
A. carbon
B. nitrogen, oxygen or fluorine
C. chlorine
D. sulphur
Answer: B
Explanation: Highly electronegative atoms enable hydrogen bonding.
32. Hydrogen bonding is strongest in
A. NH₃
B. H₂O
C. HF
D. CH₄
Answer: C
Explanation: HF has highest electronegativity difference.
33. Intermolecular hydrogen bonding increases
A. volatility
B. boiling point
C. vapour pressure
D. reactivity
Answer: B
Explanation: Strong attraction increases boiling point.
34. Ice floats on water because
A. hydrogen bonding decreases density
B. covalent bonds break
C. ionic bonds form
D. density increases
Answer: A
Explanation: Open hydrogen-bonded structure lowers density.
35. Which compound does NOT show hydrogen bonding?
A. NH₃
B. H₂O
C. HF
D. HCl
Answer: D
Explanation: Chlorine is less electronegative.
Section H: Polarity and Dipole Moment
36. Dipole moment is a product of
A. charge and mass
B. charge and distance
C. mass and distance
D. volume and charge
Answer: B
Explanation: μ = charge × distance.
37. Which molecule has zero dipole moment?
A. NH₃
B. H₂O
C. CO₂
D. SO₂
Answer: C
Explanation: Linear and symmetrical molecule.
38. Greater the electronegativity difference, the bond is
A. non-polar
B. covalent
C. polar
D. metallic
Answer: C
Explanation: Higher difference increases polarity.
39. Dipole moment helps to determine
A. molecular mass
B. shape and polarity
C. atomic number
D. valency
Answer: B
Explanation: It indicates charge separation.
40. Which molecule is polar?
A. CO₂
B. BF₃
C. CCl₄
D. NH₃
Answer: D
Explanation: Lone pair causes asymmetry.
Section I: Conceptual NCERT-Based MCQs
41. Strongest repulsion occurs between
A. bond pair–bond pair
B. bond pair–lone pair
C. lone pair–lone pair
D. nucleus–electron
Answer: C
Explanation: Lone pairs occupy more space.
42. Number of sigma bonds in ethene is
A. 4
B. 5
C. 6
D. 7
Answer: C
Explanation: One σ in double bond and four C–H σ bonds.
43. Pi bond is formed by overlap of
A. s–s
B. s–p
C. p–p sideways
D. sp–sp
Answer: C
Explanation: Sidewise overlap of p orbitals forms π bond.
44. Which bond is weakest?
A. Covalent bond
B. Ionic bond
C. Hydrogen bond
D. Metallic bond
Answer: C
Explanation: Hydrogen bond is weaker than primary bonds.
45. Which molecule has trigonal planar shape?
A. CH₄
B. BF₃
C. NH₃
D. H₂O
Answer: B
Explanation: sp² hybridisation gives trigonal planar shape.
46. Number of lone pairs on oxygen in water is
A. 1
B. 2
C. 3
D. 4
Answer: B
Explanation: Oxygen has two lone pairs.
47. Hybridisation of nitrogen in NH₃ is
A. sp
B. sp²
C. sp³
D. dsp²
Answer: C
Explanation: One lone pair and three bond pairs.
48. Which molecule shows resonance?
A. CH₄
B. NH₃
C. O₃
D. H₂O
Answer: C
Explanation: Ozone has multiple resonance structures.
49. The correct order of bond strength is
A. single < double < triple
B. triple < double < single
C. double < single < triple
D. single = double = triple
Answer: A
Explanation: More shared electrons give stronger bonds.
50. Chemical bonding explains
A. only physical properties
B. only chemical properties
C. formation and stability of molecules
D. atomic mass
Answer: C
Explanation: Bonding explains how atoms combine and remain stable.
✅ Completion Note
This completes a fully NCERT-aligned, CBSE-standard set of 50 MCQs on Chemical Bonding and Molecular Structure, ideal for concept clarity, systematic revision, and board exam preparation.