“Valence Bond Theory” MCQ with Answer Explanation : NEET 2025.

91. The bonding in methane (CH₄) can be explained by:
    A. sp hybridization
    B. sp² hybridization
    C. sp³ hybridization
    D. sp³d hybridization

Answer: C. sp³ hybridization

Explanation: In methane (CH₄), carbon undergoes sp³ hybridization, resulting in a tetrahedral structure with bond angles of 109.5°.

92. The geometry of a molecule with sp² hybridization is:
    A. Linear
    B. Trigonal planar
    C. Tetrahedral
    D. Trigonal bipyramidal

Answer: B. Trigonal planar

Explanation: sp² hybridization leads to a trigonal planar structure with bond angles of 120°. This occurs in molecules like BF₃.

93. The overlap of two p-orbitals along the internuclear axis forms a:
    A. Sigma bond
    B. Pi bond
    C. Ionic bond
    D. Hydrogen bond

Answer: A. Sigma bond

Explanation: A sigma bond is formed when two atomic orbitals overlap along the internuclear axis, resulting in head-on overlap. This is typically stronger than a pi bond, which is a sideways overlap.

94. Which of the following molecules has sp³d hybridization?
    A. SF₆
    B. NH₃
    C. PCl₅
    D. BF₃

Answer: C. PCl₅

Explanation: In phosphorus pentachloride (PCl₅), phosphorus undergoes sp³d hybridization, resulting in a trigonal bipyramidal shape with bond angles of 90° and 120°.

95. Which molecule involves delocalized pi electrons?
    A. CH₄
    B. NH₃
    C. H₂O
    D. Benzene (C₆H₆)

Answer: D. Benzene (C₆H₆)

Explanation: In benzene, the six carbon atoms are sp² hybridized, and the pi electrons are delocalized over the entire ring, leading to resonance and extra stability.

96. Which of the following molecules has a linear shape?
    A. CO₂
    B. H₂O
    C. NH₃
    D. CH₄

Answer: A. CO₂

Explanation: In carbon dioxide (CO₂), the carbon atom is sp hybridized, and the molecule has a linear structure with bond angles of 180°.

97. In VBT, resonance is used to explain:
    A. Hybridization of orbitals
    B. The delocalization of electrons in certain molecules
    C. The mixing of atomic orbitals
    D. The formation of sigma bonds

Answer: B. The delocalization of electrons in certain molecules

Explanation: Resonance in VBT refers to the delocalization of electrons across several atoms in a molecule, as seen in molecules like ozone (O₃) and benzene (C₆H₆).

98. The bond angles in NH₃ are slightly less than:
    A. 180°
    B. 120°
    C. 109.5°
    D. 90°

Answer: C. 109.5°

Explanation: In ammonia (NH₃), the nitrogen atom is sp³ hybridized, and the bond angles are approximately 107° due to the lone pair-bond pair repulsion.

99. The hybridization of carbon in ethyne (C₂H₂) is:
    A. sp
    B. sp²
    C. sp³
    D. sp³d

Answer: A. sp

Explanation: In ethyne (C₂H₂), each carbon atom undergoes sp hybridization, resulting in a linear structure with bond angles of 180°.

100. Bond dissociation energy is highest for:
     A. Pi bonds
     B. Sigma bonds
     C. Hydrogen bonds
     D. Ionic bonds

Answer: B. Sigma bonds

Explanation: Sigma bonds are generally stronger than pi bonds because they involve end-to-end overlap of atomic orbitals, which results in greater bond strength