Chemical Bonding contributes around 10% of the total marks in JEE Advanced 2025, the aspirants can expect 2-3 questions from chemical bonding in the exam.
The most commonly asked questions and subjects of Chemical Bonding from JEE Main and JEE Advanced include ionic bonds, covalent bonds, the polarity of a bond, hybridization, molecular orbital theory, resonance, and the shape of a molecule.
JEE Advanced previous year question papers and mock tests can assist IIT Aspirants to achieve higher rankings in JEE Advanced 2025.
Must Read Articles:
- Download JEE Advanced Syllabus 2025
- Download JEE Advanced 2024 Paper With Detailed Solutions
- JEE Advanced Previous Year Question Paper PDF Download
Listed below is the list of Chemical Bonding and Molecular Structure questions with detailed solutions asked in JEE Advanced exam 2025:
Question 1:
Among [Co(CN)4]4−, [Co(CO)3(NO)], XeF4, [PCl4 ]+, [PdCl4 ]2− , [ICl4 ]− , [Cu(CN)4]3− and P4 the total number of species with tetrahedral geometry is _____.
Question 2:
A sample initially contains only U-238 isotope of uranium. With time, some of the U-238 radioactively decays into Pb-206 while the rest of it remains undisintegrated.
When the age of the sample is P x108 years, the ratio of mass of Pb-206 to that of U-238 in the sample is found to be 7. The value of P is _____.
[Given: Half-life of U-238 is 4.5 x109 years; loge2 = 0.693]
Question 3:
The species formed on fluorination of phosphorus pentachloride in a polar organic solvent are
- [PF4]+[PF6]- and [PCl4]+[PF6]-
- [PCl4]+[PCl4F2]- and [PCl4]+[PF6]-
- PF3 and PCl3
- PF5 and PCl3
Question 4:
Based on VSEPR model, match the xenon compounds given in List-I with the corresponding geometries and the number of lone pairs on xenon given in List-II and choose the correct option.
| List I | List II | ||
|---|---|---|---|
| (P) | XeF2 | (1) | Trigonal bipyramidal and two lone pair of electrons |
| (Q) | XeF4 | (2) | Tetrahedral and one lone pair of electrons |
| (R) | XeO3 | (3) | Octahedral and two lone pair of electrons |
| (S) | XeO3F2 | (4) | Trigonal bipyramidal and no lone pair of electrons |
| (5) | Trigonal bipyramidal and three lone pair of electrons | ||
- P-5, Q-2, R-3, S-1
- P-5, Q-3, R-2, S-4
- P-4, Q-3, R-2, S-1
- P-4, Q-2, R-5, S-3
Question 5:
The option(s) in which at least three molecules follow Octet Rule is(are)
- CO2, C2H4, NO and HCl
- NO2, O3, HCl and H2SO4
- BCl3, NO, NO2 and H2SO4
- CO2, BCl3, O3 and C2H4
Question 6:
H2S (5 moles) reacts completely with acidified aqueous potassium permanganate solution. In this reaction, the number of moles of water produced is x, and the number of moles of electrons involved is y. The value of (x + y) is ____.
Question 7:
Question 8:
For diatomic molecules, the correct statement(s) about the molecular orbitals formed by the overlap to two 2pz orbitals is(are):
Question 9:
The amount of energy required to break a bond is the same as the amount of energy released when the same bond is formed. In a gaseous state, the energy required for homolytic cleavage of a bond is called Bond Dissociation Energy (BDE) or Bond Strength. BDE is affected by the s-character of the bond and the stability of the radicals formed. Shorter bonds are typically stronger bonds. BDEs for some bonds are given below:
Correct match of the C–H bonds (shown in bold) in Column J with their BDE in Column K is
| Column J Molecule | Column K BDE (kcal mol–1 ) | ||
|---|---|---|---|
| P | H–CH(CH3)2 | i | 132 |
| Q | H–CH2Ph | ii | 110 |
| R | H–CH=CH2 | iii | 95 |
| S | H–C≡CH | iv | 88 |
- P – iii, Q – iv, R – ii, S – i
- P – i, Q – ii, R – iii, S – iv
- P – iii, Q – ii, R – i, S – iv
- P – ii, Q – i, R – iv, S – iii
Question 10:
The 1st ,2nd , and the 3rd ionization enthalpies, I1,I2, and I3, of four atoms with atomic numbers n,n+1, n+2, and n+3, where ???? < 10, are tabulated below. What is the value of n?
| Atomic Number | Ionization Enthalpy (kJ/mol) | ||
|---|---|---|---|
| I1 | I2 | I3 | |
| n | 1681 | 3374 | 6050 |
| n+1 | 2081 | 3952 | 6122 |
| n+2 | 469 | 4562 | 6910 |
| n+3 | 738 | 1451 | 7733 |
Question 11:
The figure below is the plot of potential energy versus internuclear distance (d) of H2 molecule in the electronic ground state. What is the value of the net potential energy E0 (as indicated in figure) in kJmol−1, for d=d0 at which the electron-electron repulsion and the nucleus-nucleus repulsion energies are absent? As reference, the potential energy of H atom is taken as zero when its electron and the nucleus are infinitely far apart. Use Avogadro constant as 6.023×1023mol−1
Question 12:
Each of the following options contains a set of four molecules. Identify the option(s) where all four molecules possess permanent dipole moment at room temperature.
- BeCl2,CO2,BCE,CHCI3
- NO2,NH3,POCh,CH3CI
- BF3,O3,SF6,XeF6
- SO2,(XH5Cl,H2Se,BrF5)
Question 13:
Assuming 2s−2p mixing is not operative, the paramagnetic species among the following is
- Be2
- B2
- C2
- N2
Question 14:
The shape of XeO2F2 molecule is -
- trigonal bipyramidal
- square planar
- tetrahedral
- see-saw
Question 15:
Assuming that Hund's rule is violated, the bond order and magnetic nature of the diatomic molecule
B2 is-
- 1 and diamagnetic
- 0 and diamagnetic
- 1 and paramagnetic
- 0 and paramagnetic
JEE Advanced Exam Pattern 2025
The JEE Advanced exam consists of two papers i.e. 1 and 2 and it is compulsory for students to appear in both papers. Paper 1 will be conducted in the morning and Paper 2 in the afternoon. Students can appear for the exam in either of the languages English and Hindi.
JEE Advanced 2025 Exam Pattern Highlights
| Particulars | Highlights |
|---|---|
| Total Number of Paper | Two Paper (Paper 1 and 2) |
| Total Subjects | 3 (Mathematics, Physics, Chemistry) |
| Total Sections | 4 |
| Total Questions | 102 |
| Total Questions in each Subject | 17 |
| Total Marks | 360 |
| Total Marks in each Paper | 180 |
| Total Marks in each Subject | 60 |
| Negative Marking | Yes ( except Section III in Paper 1 and 2 and Section IV in Paper 2) |
| Type of Questions | MCQ, NAT, Statement-based, Match the Following |
| Exam Duration | 3 hours each paper |
JEE Advanced Chapter-wise Weightage
The JEE Advanced chapter-wise weightage helps you understand which topics carry more importance in the exam. By focusing on high-weightage chapters, you can improve your exam preparation. For example, in Mathematics, topics like Calculus and Algebra usually carry about 50-60% of the questions, while in Physics, Mechanics and Electromagnetism contribute more.
JEE Advanced Exam – Topic-wise (Chemistry)
| Topics | Weightage | Total Marks | Total Questions |
|---|---|---|---|
| Class 11 | |||
| Inorganic Chemistry-I (Chemical Bonding and Molecular Structure, p-Block Elements -Group 13 & 14) | 16% | 19 | 5 |
| Organic Chemistry-I (Benzene, Basic Principles of Organic Chemistry) | 11% | 13 | 4 |
| Physical Chemistry-I (Chemical Thermodynamics, Chemical and Ionic Equilibrium, Mole Concept-I, Atomic Structure, States of Matter: Gases and Liquids) | 24% | 29 | 8 |
| Class 12 | |||
| Inorganic Chemistry-II (Coordination Compounds,Isolation of Metals, d-Block Elements) | 11% | 13 | 4 |
| Organic Chemistry-Il (Phenols, Alkyl Halides, Biomolecules, Amines, Ethers) | 23% | 28 | 8 |
| Physical Chemistry-II (Surface Chemistry, Chemical Kinetics, Solid State, Electrochemistry, Solutions) | 15% | 8 | 5 |
Detailed JEE Advanced 2025 Marking Scheme
Candidates must note that the JEE Advanced marking scheme will be the same for both Paper 1 and Paper 2. However, the marks allotted to each section of the subjects will be different. Here is the detailed marking scheme for each section of the exam paper:
Marking Scheme for Paper 1 and Paper 2
| Sections | Total Marks | Marking Scheme |
|---|---|---|
| Section I | 12 | +3 for every correct answer, 0 marks for unanswered questions. |
| Section II | 12 | +4 if all correct options are selected; +3 if three out of four correct options are selected; +2 if two out of 3+ correct options are selected; +1 if one out of 2+ options is selected; 0 if unanswered. |
| Section III | 24 | +4 if only the correct integer value entered, 0 if unanswered or the answer is wrong. |
| Section IV | 12 | +3 if an option with the correct combinations is chosen; 0 if unanswered in Paper 1.+3 if the correct value is put; 0 if unanswered in Paper 2. |
Previous Years’ Question Paper
JEE Advanced 2024 Question Paper PDF
| Paper | Question Paper PDF | Answer Key PDF |
|---|---|---|
| Question Paper 1 PDF | Download PDF | Download PDF |
| Question Paper 2 PDF | Download PDF | Download PDF |
JEE Advanced 2023 Question Paper PDF
| Paper | Question Paper PDF | Answer Key PDF |
|---|---|---|
| Question Paper 1 PDF | Download PDF | Download PDF |
| Question Paper 2 PDF | Download PDF | Download PDF |
JEE Advanced 2022 Question Paper PDF
| Paper | Question Paper PDF | Answer Key PDF |
|---|---|---|
| Question Paper 1 PDF | Download PDF | Download PDF |
| Question Paper 2 PDF | Download PDF | Download PDF |
JEE Advanced 2021 Question Paper PDF
| Question Paper | PDF Download | ||
|---|---|---|---|
| Question Paper 1 PDF | Physics | Chemistry | Maths |
| Question Paper 2 PDF | Physics | Chemistry | Maths |
JEE Advanced 2020 Question Paper
| Question Paper | Question Paper PDF | Answer Key PDF |
|---|---|---|
| Question Paper 1 PDF | Download PDF | Download PDF |
| Question Paper 2 PDF | Download PDF | Download PDF |
Frequently Asked Questions:
Q1. What is the weightage of chemical Bonding in JEE Advanced exam 2025?
Answer: Chemical Bonding contributes around 10% of the total marks in JEE Advanced , which is approximately 2-3 questions in the exam.
Topics Covered:
- Ionic Bonding: Understand by lattice energy, by Born-Haber cycle, and by properties of ionic compounds.
- Covalent Bonding: Study on valence bond theory, hybridization (one on sp, one on sp², one on sp³), precise bond angles, and the full concept upon resonance.
- Molecular Orbital Theory: Discover the process of molecular orbital creation along with its use for predicting both the bonding and magnetic properties of molecules.
Q2. Is chemical Bonding important for JEE Advanced exam 2025?
Answer: Yes, Chemical Bonding is an important chapter for JEE Advanced preparation. It helps in understanding the structure and behavior of molecules, which is required not only for Physical Chemistry but also for Inorganic Chemistry.
As per the previous years the weightage and number of questions of Chemical Bonding in the JEE Advanced exams
| Year | Number of Questions on Chemical Bonding | Weightage |
|---|---|---|
| 2023 | 1-2 questions | 3-4% |
| 2022 | 1 question | 3% |
| 2021 | 1-2 questions | 3-5% |
| 2020 | 1 question | 3% |
Q3. Which part of Chemistry has more weightage in the JEE Advanced exam?
Answer: As per the paper analysis, the weightage of Chemistry in JEE Advanced Paper is as follows:
- Physical and Inorganic Chemistry: Each contributes approximately 30% of the total Chemistry marks.
- Organic Chemistry: Accounts for about 35% of the total Chemistry marks.
The JEE Main Chemistry important topics in each section are as follows:
| Part of Chemistry | Weightage in JEE | Key Topics |
|---|---|---|
| Physical Chemistry | 30% | Thermodynamics, Chemical Kinetics, Chemical Equilibrium, Electrochemistry, Solutions, Redox Reactions, Surface Chemistry |
| Inorganic Chemistry | 30% | Periodic Table and p-Block Elements, d-Block and f-Block Elements, Coordination Compounds, Qualitative Analysis, Chemical Bonding |
| Organic Chemistry | 35% | General Organic Chemistry, Stereochemistry, Hydrocarbons, Functional Groups (Alcohols, Ethers, Aldehydes, Ketones, Carboxylic Acids, etc.), Reaction Mechanisms, Polymers |
Q4.Chemical Bonding Important Topics for JEE Advanced exam?
Answer: Chemical Bonding is an important topic in JEE Advanced Chemistry, and it helps in understanding molecular interactions.
Here are the important topics of Chemical Bonding:
| Topic | Details |
| Ionic Bonding | Lattice energy, Born-Haber cycle, properties of ionic compounds, solubility, and electrical conductivity. |
| Covalent Bonding | Valence Bond Theory (VBT), hybridization (sp, sp², sp³), bond angles, and resonance structures. |
| Molecular Orbital Theory (MOT) | Molecular orbital formation, bond order, paramagnetism, diamagnetism, and energy diagrams. |
| Hybridization | sp, sp², sp³, and their implications on bond angles and geometry. |
| Polarity of Molecules | Dipole moment, molecular polarity, and the impact on molecular shape and behavior. |
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