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Chemical Bonding and Molecular Structure appeared 41 times across 3 years — 4.9% of Chemistry. This question is from Hybridization.

Year 2026 2025 2024 Total
Questions 12 13 16 41

In SO₂, NO₂^- and N₃^- the hybridizations at the central atom are respectively:

Solution & Explanation

Related Formula
Steric Number (Steric count) = Number of lone pairs on central atom + Number of σ-bonds
Core Logic

Let's perform steric calculations for each species:

  • SO₂: Central sulfur atom has 6 valence electrons, forms 2 σ-bonds (and 2 π-bonds) with oxygen, leaving 1 lone pair. Steric number = 2 + 1 = 3 sp².
  • NO₂^-: Central nitrogen atom has 5 valence electrons + 1 from negative charge = 6. It forms 2 σ-bonds, leaving 1 lone pair. Steric number = 2 + 1 = 3 sp².
  • N₃^- (Azide ion): Linear configuration structure can be drawn as:
N= +N= N

The central nitrogen has 2 σ-bonds and 0 lone pairs. Steric number = 2 + 0 = 2 sp.

Step 1: Geometry Outlines

The individual orbital fields are represented visually:

Hybridization diagram for Q39 - JEE Main 2025 Evening
Hybridization diagram for Q39 - JEE Main 2025 Evening

Hence, hybridizations follow the order: sp², sp², and sp.

Pattern Recognition

Steric short tracking: Species with linear structures like CO₂, N₂O, N₃^- possess central atoms that are always sp hybridized due to the requirement of two opposing σ-bonds.

Chapter Mix

Class 11 Chemistry: Chemical Bonding and Molecular Structure

Reference Study Guides

More Chemical Bonding and Molecular Structure Previous-Year Questions — Page 7

Q89 jee_main_2024_27_jan_morning Molecular Orbital Theory
Sum of bond order of CO and NO^+ is .
Numerical Answer. Answer: 6 to 6

Solution

Step 1: Determine the bond order of CO

Carbon monoxide (CO) contains 6 + 8 = 14 total electrons. Its structural representation is C, matching a bond order value of 3.

Step 2: Determine the bond order of NO^+

The nitrosonium ion (NO^+) contains 7 + 8 - 1 = 14 total electrons. Since it is isoelectronic with N₂ and CO (14 electrons), its corresponding bond order value is also 3.

Step 3: Sum the results
Sum = 3 + 3 = 6
Pattern Recognition

Isoelectronic species possessing 14 total electrons consistently demonstrate a bond order value of 3.

Chapter Mix

Class 11 Chemistry: Chemical Bonding and Molecular Structure

Q81 jee_main_2024_29_jan_morning VSEPR Theory
Number of compounds with one lone pair of electrons on central atom amongst following is O₃, H₂O, SF₄, ClF₃, NH₃, BrF₅, XeF₄
Numerical Answer. Answer: 4 to 4

Solution

Core Logic

Let us determine the steric number (Z) and number of lone pairs (LP) for the central atom in each given molecule. Formula: Z = (1)/(2) (V + M - C + A) Where V = valence electrons on central atom, M = number of monovalent atoms, C = cationic charge, A = anionic charge. LP = Z - Bond Pairs (B.P.)

  • O₃: Central atom O (V=6). It forms one double bond and one dative bond. It has 1 lone pair remaining.
  • H₂O: Central atom O (V=6). Z = (1)/(2)(6 + 2) = 4. LP = 4 - 2 = 2.
  • SF₄: Central atom S (V=6). Z = (1)/(2)(6 + 4) = 5. LP = 5 - 4 = 1 (See-saw shape).
  • ClF₃: Central atom Cl (V=7). Z = (1)/(2)(7 + 3) = 5. LP = 5 - 3 = 2 (T-shape).
  • NH₃: Central atom N (V=5). Z = (1)/(2)(5 + 3) = 4. LP = 4 - 3 = 1 (Pyramidal).
  • BrF₅: Central atom Br (V=7). Z = (1)/(2)(7 + 5) = 6. LP = 6 - 5 = 1 (Square Pyramidal).
  • XeF₄: Central atom Xe (V=8). Z = (1)/(2)(8 + 4) = 6. LP = 6 - 4 = 2 (Square Planar).
Step 1: Final Counting

VSEPR Theory diagram for Q81 - JEE Main 2024 Morning
VSEPR Theory diagram for Q81 - JEE Main 2024 Morning
VSEPR Theory diagram for Q81 - JEE Main 2024 Morning
VSEPR Theory diagram for Q81 - JEE Main 2024 Morning
VSEPR Theory diagram for Q81 - JEE Main 2024 Morning
VSEPR Theory diagram for Q81 - JEE Main 2024 Morning

The compounds containing exactly ONE lone pair on the central atom are O₃, SF₄, NH₃, and BrF₅.

Total count = 4.

Chapter Mix

Class 11 Chemistry: Chemical Bonding and Molecular Structure

Q88 jee_main_2024_29_jan_morning Molecular Orbital Theory
The number of species from the following which are paramagnetic and with bond order equal to one is H₂, He₂^+, O₂^+, N₂²⁻, O₂²⁻, F₂, Ne₂^+, B₂
Numerical Answer. Answer: 1 to 1

Solution

Core Logic

Using Molecular Orbital (MO) Theory, we evaluate the bond order (BO = (Nb - Nₐ)/(2)) and magnetic nature (unpaired electrons = paramagnetic, all paired = diamagnetic) for each species:

SpeciesMagnetic behaviourBond order
H₂Diamagnetic1
He₂^+Paramagnetic0.5
O₂^+Paramagnetic2.5
N₂²⁻Paramagnetic2
O₂²⁻Diamagnetic1
F₂Diamagnetic1
Ne₂^+Paramagnetic0.5
B₂Paramagnetic1

Step 1: Final Selection

We need the species that satisfies BOTH conditions:

  • Paramagnetic
  • Bond Order = 1
  • Looking at the table, B₂ is the only molecule that is paramagnetic (it has 2 unpaired electrons in degenerate π₂ₚ orbitals) and has a bond order of 1.

    Total number of such species = 1.

Pattern Recognition

B₂ (10 electrons) and O₂ (16 electrons) are the classic exceptions in MO theory that are paramagnetic despite having an even number of electrons. B₂ has BO = 1, and O₂ has BO = 2.

Chapter Mix

Class 11 Chemistry: Chemical Bonding and Molecular Structure

Q jee_main_2024_30_january_evening VSEPR Theory and Molecular Shapes
The molecule/ion with square pyramidal shape is:
  • A. [Ni(CN)₄]²⁻
  • B. PCl₅
  • C. BrF₅
  • D. PF₅

Solution

Core Logic

According to VSEPR theory:

  • [Ni(CN)₄]²⁻: dsp² hybridization arrow Square Planar.
  • PCl₅: sp³d hybridization with 0 lone pairs arrow Trigonal Bipyramidal.
  • BrF₅: Bromine has 7 valence electrons. It forms 5 single bonds with Fluorine, leaving 1 lone pair. sp³d² hybridization arrow geometry is octahedral, but shape is Square Pyramidal.
  • PF₅: sp³d hybridization with 0 lone pairs arrow Trigonal Bipyramidal.
  • Square Pyramidal structure of BrF5 diagram for Q69 - JEE Main 2024 Evening
    Square Pyramidal structure of BrF5 diagram for Q69 - JEE Main 2024 Evening

Pattern Recognition

AX₅E₁ configuration (5 bond pairs + 1 lone pair) typically yields a Square Pyramidal shape.

Chapter Mix

Class 11 Chemistry: Chemical Bonding and Molecular Structure Class 12 Chemistry: Coordination Compounds

Q jee_main_2024_30_january_evening Dipole Moment
Given below are two statements: Statement-I: Since fluorine is more electronegative than nitrogen, the net dipole moment of NF₃ is greater than NH₃. Statement-II: In NH₃, the orbital dipole due to lone pair and the dipole moment of NH bonds are in opposite direction, but in NF₃ the orbital dipole due to lone pair and dipole moments of N-F bonds are in same direction. In the light of the above statements. Choose the most appropriate from the options given below.
  • A. Statement I is true but Statement II is false.
  • B. Both Statement I and Statement II are false.
  • C. Both statement I and Statement II is are true.
  • D. Statement I is false but Statement II is are true.

Solution

Core Logic

Statement I: The net dipole moment of NH₃ (1.47 D) is actually greater than that of NF₃ (0.23 D). Therefore, Statement I is false.

Statement II: In NH₃, the N-H bond dipole moments (pointing towards the more electronegative N) reinforce the orbital dipole moment of the lone pair. In NF₃, the N-F bond dipole moments point away from N (towards the more electronegative F), opposing the orbital dipole moment of the lone pair. This partial cancellation in NF₃ makes its net dipole moment lower. Therefore, Statement II is also false, as it reverses the correct orientations.

Dipole moments in NH3 and NF3 diagram for Q75 - JEE Main 2024 Evening
Dipole moments in NH3 and NF3 diagram for Q75 - JEE Main 2024 Evening
Dipole moments in NH3 and NF3 diagram for Q75 - JEE Main 2024 Evening
Dipole moments in NH3 and NF3 diagram for Q75 - JEE Main 2024 Evening

Step 1: Final Conclusion

Since both statements assert the opposite of established facts regarding NH₃ and NF₃, both are false.

Chapter Mix

Class 11 Chemistry: Chemical Bonding and Molecular Structure

More Chemical Bonding and Molecular Structure Questions — jee_main_2025_07_april_evening

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