NEET Previous Year Questions (2014-2024): Chemical Bonding & Molecular Structure | Chemistry Class 11 PDF Download

2024

Q1: Match List I with List II.
Choose the correct answer from the options given below:
(a) A-I, B-IV, C-II, D-III
(b) A-II, B-IV, C-III, D-I
(c) A-III, B-IV, C-I, D-II
(d) A-II, B-III, C-IV, D-I                      (NEET 2024)
Ans: 

Q2: Identify the correct answer.
(a) Three resonance structures can be drawn for ozone
(b) BF₃ has non-zero dipole moment
(c) Dipole moment of $\mathrm{NF}\mathrm{<sub\; style="word-break:\; break-word;\; line-height:\; 1.8;\; letter-spacing:\; inherit\; !important;\; color:\; black;">3</sub>}$ is greater than that of NH₃ 
(d) Three canonical forms can be drawn for CO₃^2- ion     (NEET 2024)
Ans: (d)
(1) In ozone; there are two resonating structures.

2023

Q2: The correct order of energies of molecular orbitals of N₂ molecule, is    (NEET 2023)
(a) σ1s < σ*1s < σ2s < σ*2s < (π2pₓ = π2py) < σ2pz < (π*2pₓ = π*2py) < σ*2pz
(b) σ1s < σ*1s < σ2s < σ*2s < σ2pz < (π2pₓ = π2py) < (π*2pₓ = π*2py) < σ*2pz
(c) σ1s < σ*1s < σ2s < σ*2s < σ2pz < σ*2pz < (π2pₓ = π2py) < (π*2pₓ = π*2py)
(d) σ1s < σ*1s < σ2s < σ*2s < (π2pₓ = π2py) < (π*2pₓ = π*2py) < σ2pz < σ*2pz
Ans: (a)
For molecules like B₂, C₂, N₂ etc. the increasing order of energies of various molecular orbitals is
σ1s < σ*1s < σ2s < σ*2s < (π2pₓ = π2py) < σ2pz < (π*2pₓ = π*2py) < σ*2pz

Q3: Taking stability as the factor, which one of the following represents correct relationship?
(a) InI$\mathrm{<sub\; style="word-break:\; break-word;\; line-height:\; 1.8;\; letter-spacing:\; inherit\; !important;\; color:\; black;"><strong\; style="word-break:\; break-word;\; line-height:\; 1.8;\; letter-spacing:\; inherit\; !important;\; color:\; black;">3</strong></sub>}$ > lnI 
(b) AlCl > AlCl₃
(c) TlI > TlI₃
(d) TlCl$\mathrm{<sub\; style="word-break:\; break-word;\; line-height:\; 1.8;\; letter-spacing:\; inherit\; !important;\; color:\; black;"><strong\; style="word-break:\; break-word;\; line-height:\; 1.8;\; letter-spacing:\; inherit\; !important;\; color:\; black;">3</strong></sub>}$ > TlCl      (NEET 2023)
Ans: (c)

Q4: Intermolecular forces are forces of attraction and repulsion between interacting particles that will include:
A. dipole - dipole forces.
B. dipole - induced dipole forces
C. hydrogen bonding
D. covalent bonding
E. dispersion forces
Choose the most appropriate answer from the options given below :
(a) A, B, C, D are correct
(b) A, B, C, E are correct
(c) A, C, D, E are correct
(d) B, C, D, E are correct    (NEET 2023)
Ans: (b)
Intermolecular forces means force of attraction between two or more molecules
dipole-dipole (attraction between two or more polar molecules).
Dipole induced dipole (attraction between polar and non polar molecules)
Hydrogen bonding (it is a special type of dipole-dipole and ion-dipole attraction)
Dispersion forces (mainly acts between non polar molecules).
Covalent bonding (acts between atom not between molecules )

2022

Q1: Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R)
Assertion (A) : ICI is more reactive than I₂
Reason (R) : I-CI bond is weaker than I-I bond.
In the light of the above statements, choose the most appropriate answer from the options given below:
(a) Both (A) and (R) are correct and (R) is the correct explanation of (A).
(b) Both (A) and (R) are correct but (R) is not the correct explanation of (A).
(c) (A) is correct but (R) is not correct.
(d) (A) is not correct but (R) is correct.     (NEET 2022 Phase 1)
Ans: (a)
In general, interhalogen compounds are more reactive than halogens (except fluorine). This is because X - X' bond in interhalogens is weaker than X - X bond in halogens excepts F - F bond. Therefore I-Cl is more reactive than I2 because of weaker I - Cl bond then I - I bond.

Q2: Amongst the following which one will have maximum ‘lone pair-lone pair’ electron repulsions?    (NEET 2022 Phase 1)
(1) SF₄
(2) XeF₂
(3) ClF₃
(4) IF₅
Ans: b
In XeF₂, the central atom Xe has 3 lone pairs around it.

Q3: Which amongst the following is incorrect statement?    (NEET 2022 Phase 1)
(a) ion has one electron.
(b) ion is diamagnetic.
(c) The bond orders of are 2.5, 2, 1.5 and 1, respectively.
(d) C₂ molecule has four electrons in its two degenerate π molecular orbitals.  
Ans: b
is paramagnetic, as it has one unpaired electron. (15e^–)

Q4: Match List-I with List-II :    (NEET 2022 Phase 2)

Choose the correct answer from the options given below : 
(a) (a) - (iii), (b) - (iv), (c) - (i), (d) - (ii)
(b) (a) - (ii), (b) - (iii), (c) - (iv), (d) - (i)
(c) (a) - (iii), (b) - (iv), (c) - (ii), (d) - (i)
(d) (a) - (iv), (b) - (iii), (c) - (i), (d) - (ii)
Ans: (c)

Q5: The correct order of bond angles in the following compounds/species is :
(a)

(b)

(c)

(d)     (NEET 2022 Phase 2)

Ans: (b)

2021

Q1: BF₃ is planar and electron deficient compound. Hybridization and number of electrons around the central atom, respectively are:     (NEET 2021)
(a) Sp² and 6
(b) sp² and 8
(c) sp³ and 4
(d) sp³ and 6
Ans: (a)

Geometry of Molecules in which the Central Atom has No Lone Pair of Electrons

Hint: 1 bond pair means two electrons

BF3 =  = 3σ band = sp²

The number of bond pairs is three. One bond pair needs two electrons. So, the number of electrons for the three bond pairs is 6.

Q2: Match List - I with List - II     (NEET 2021)

Choose the correct answer from the options given below
(a) (a) - (iii), (b) - (i), (c) - (iv), (d) - (ii)
(b) (a) - (iv), (b) - (iii), (c) - (ii), (d) - (i)
(c) (a) - (iv), (b) - (iii), (c) - (i), (d) - (ii)
(d) (a) - (ii), (b) - (iii), (c) - (iv), (d) - (i)
Ans: c

Hint: Sp³ = tetrahedral, sp³d = trigonal bipyramidal, and sp³d² = octahedral

1. The hybridization of P in PCl₅ is sp³d. The geometry of PCl₅ is trigonal bipyramidal.
2. The hybridization of S in SF₆ is sp³d². The geometry of SF₆ is octahedral.
3. The hybridization of Br in BrF₅ is sp³d². It contains 5 bond pairs and one lone pair. Hence, its shape is square pyramidal.
4. The hybridization of B in BF₃ is sp². The geometry of BF₃ is square planar.

Hence, option third is the correct answer.

Q3: The correct sequence of bond enthalpy of 'C-X' bond is :     (NEET 2021)
(a) CH₃ - Cl > CH₃ - F > CH₃ - Br > CH₃ - l 
(b) CH₃ - F < CH₃ - Cl < CH₃ - Br < CH₃ - l 
(c) CH₃ - F > CH₃ - Cl > CH₃ - Br > CH₃ - l 
(d) CH₃ - F < CH₃ - Cl > CH₃ - Br > CH₃ - l 
Ans: (c)
On moving down the group from F to I, the size of atom increases. Order of the size of halogen atoms is I > Br > Cl > F.
So, the bond length of C—X bond also increases from F to I and hence, the bond enthalpy decreases from F to I. Correct order of bond length of C—X bond is
H₃C - I > H₃C - Br > H₃C - Cl > H₃C - F.
Correct order of bond enthalpy is
H₃C - F > H₃C - Cl > CH₃ - Br > H₃C - I. 

Q4: The non-polar nature molecule among the following is-     (NEET 2021)
(a) SbCl₅
(b) NO₂
(c) POCl₃
(d) CH₂O
Ans:  (a)
 Dipole moment depends on the structure of the compound.
The structure of SbCl₅, NO₂, POCl₃, and CH₂O is as follows:
The SbCl5 is a non-polar compound because it has zero dipole moment. The SbCl₅ is a symmetrical molecule thus it has a net dipole moment is zero.

2020

Q1: Which of the following set of molecules will have zero dipole moment ?      (NEET 2020)
(a) Nitrogen trifluoride, beryllium difluoride, water, 1,3-dichlorobenzene 
(b) Boron trifluoride, beryllium difluoride, carbon dioxide, 1,4-dichlorobenzene 
(c) Ammonia, beryllium difluoride, water 1,4-dichlorobenzene 
(d) Boron trifluoride, hydrogen fluoride, carbon dioxide, 1,3-dichlorobenzene
Ans: (b)

Q2: Identify a molecule which does not exist.     (NEET 2020)
(a) C₂ 
(b) O₂ 
(c) He₂ 
(d) Li₂
Ans: c
Diatomic molecule for which bond order is zero or negative does not exist.

2019

Q1: Which of the following diatomic molecular species has only π bonds according to Molecular Orbital Theory?    (NEET 2019)
(a) O₂
(b) N₂
(c) C₂
(d) Be₂
Ans: (c)
MO configuration C₂ is:

Q2: The number of sigma (σ) and pi (π) bonds in pent-2-en-4-yne is -    (NEET 2019)
(a) 11 σ bonds and 2 π bonds
(b) 13 σ bonds and no π bonds
(c) 10 σ bonds and 3 π bonds
(d) 8 σ bonds and 5 π bonds
Ans: (c)
H–C $\equiv$ C – CH = CH – CH₃
Here, 10 σ bonds and 3 π bonds are presents. 

Q3: The manganate and permanganate ions are tetrahedral due to :   (NEET 2019)
(a) The π-bonding involves overlap of p-orbitals of oxygen with p-orbtials of manganese
(b) The π-bonding involves overlap of d-orbitals of oxygen with d-orbitals of manganese
(c) The π-bonding involves overlap of p-orbitals of oxygen with d-orbitals of manganese
(d) There is no π-bonding
Ans: (c)

Q4:  Identify the incorrect statement related to PCl₅ from the following:    (NEET 2019)
(a) Three equatorial P–Cl bonds make an angle of 120° with each other
(b) Two axial P–Cl bonds make an angle of 180° with each other
(c) Axial P–Cl bonds are longer than equatorial P–Cl bonds
(d) PCl₅ molecule is non-reactive
Ans: (d)

(1) True

(3) TrueAxial bond : 240 pm
Equatorial bond : 202 pm
(4) False
Due to longer and hence weaker axial bonds, PCl₅ is a reactive molecule.

2018

Q1: Consider the following species: CN⁺, CN^–, NO and CN
Which one of these will have the highest bond order?    (NEET 2018)
(a) NO
(b) CN^–
(c) CN⁺
(d) CN
Ans: (b)

Q2: In the structure of ClF₃ , the number of lone pairs of electrons on central atom ‘Cl’ is    (NEET 2018)
(a) one
(b) two
(c) four
(d) three
Ans: (b)

Hence, Cl has 2 lone pairs of electrons.

2017

Q1: Which of the following pairs of species have the same bond order?    (NEET 2017)
(a) O₂, NO⁺
(b) CN^–, CO
(c) N₂ , O₂^-
(d) CO, NO
Ans: (b)
Total no. of electrons in CN^– is 14
Total no. of electrons in CO is also 14
Hence, B.O. of both CN^– & CO is 3

Q2: The species, having bond angles of 120^o is   (NEET 2017)
(a) ClF₃
(b) NCl₃
(c) BCl₃
(d) PH₃
Ans: (b)
BCl₃-Trigonal planar, sp²-hybridised, 120^o angle 

2016

Q1: Predict the correct order among the following :   (NEET 2016 Phase 1)
(a) Ione pair - bond pair > bond pair - bond pair > lone pair - lone pair
(b) lone pair - lone pair > lone pair - bond pair > bond pair - bond pair
(c) lone pair - lone pair > bond pair - bond pair > lone pair - bond pair
(d) bond pair - bond pair > lone pair - bond pair > lone pair - lone pair
Ans: (b)
The order of repulsion force according to VSEPR theory :
lone pair - lone pair > lone pair - bond pair > bond pair - bond pair

Q.20. Consider the molecules CH₄, NH₃ and H₂O. Which of the given statement is false?    (NEET 2016 Phase 1)
(a) The H-C-H bond angle in CH₄ is larger than the H-N-H bond angle in NH₃
(b) The H-C-H bond angle in CH₄, the H-N-H bond angle in H₂O are all greater than 90°.
(c) The H-O-H bond angle in H₂O  is larger than the H-C-H bond angle in CH₄.
(d) The H-O-H bond angle in H₂O is smaller than the H-N-H bond angle in NH₃.
Ans: (c)
The H-O-H bond angle in H₂O  is larger than the H-C-H bond angle in CH₄.
According to VBT: lone pair-lone pair repulsion is more than a bond pair -lone pair repulsion.
As the number of lone pair of electrons on central element increases, repulsion between that lone pair of electrons increases and therefore, bond angle decreases.

Q3: Among the following, which one is a wrong statement ?    (NEET 2016 Phase 2)
(a) PH₅ and BiCl₅ do not exist. 
(b) pπ-dπ bonds are present in SO₂. 
(c) SeF₄ and CH₄ have same shape. 
(d) I₃⁺ has bent geometry. 
Ans: (c)

Q4: The correct geometry and hybridization for XeF₄ are    (NEET 2016 Phase 2)
(a) octahedral, sp³d² 
(b) trigonal bipyramidal, sp³d 
(c) planar triangle, sp³d³ 
(d) square planar, sp³d² 
Ans: (a)

sp³d² hybridisation (octahedral geometry, square planar shape)

Q5: The hybridizations of atomic orbitals of nitrogen in NO₂⁺, NO₃⁻  and  NH₄⁺  respectively are
(a) sp, sp³ and sp² 
(b) sp², sp³ and sp₃ 
(c) sp, sp² and sp³ 
(d) sp², sp and sp³   (NEET 2016 Phase 2)
Ans: (c)

Q6: Which one of the following compounds shows the presence of intramolecular hydrogen bond?
(a) H₂O₂
(b) HCN
(c) Cellulose
(d) Concentrated acetic acid   (NEET 2016 Phase 2)
Ans: (c)
H₂O₂, HCN and conc. CH₃COOH form intermolecular hydrogen bonding while cellulose has intramolecular hydrogen bonding.

2015

Q1: The correct bond order in the following species is:    (NEET / AIPMT 2015)
(a)

(b)

(c)

(d)

Ans: (a)

Q2: Maximum bond angle at nitrogen is present in which of the following ?   (NEET / AIPMT 2015)
(a) NO₂⁺ 
(b) NO₃ -
(c) NO₂
(d) NO₂^-
Ans: (a)

Q3: In which of the following pairs, both the species are not isostructural ?      (NEET / AIPMT 2015)
(a) Diamond, Silicon carbide
(b) NH₃, PH₃
(c) XeF₄, XeO₄
(d) SiCl₄, PCl₄⁺
Ans: (c) 

Q4: Decreasing order of stability of O₂, O₂^$-$, O₂⁺ and O₂^2$-$ is        (NEET / AIPMT 2015)
(a) O₂^2$-$  >  O₂^$-$  >  O₂  >  O₂⁺
(b) O₂  >  O₂⁺  >  O₂^2$-$  >  O₂^$-$
(c) O₂^$-$  >  O₂^2$-$  >  O₂⁺  >  O₂
(d) O₂⁺  >  O₂  >  O₂^$-$  >  O₂²
Ans: (d)
According to molecular orbital theory as bond order decreases stability of the molecule decreases.

2014

Q1: Which one of the following species has plane triangular shape?    (NEET / AIPMT 2014)
(a)
(b) CO₂
(c) N₃
(d)
Ans: (d)
Species with sp² hybridisation are plane triangular in shape. Among the given species  is sp² hybridised with no lone pair of electrons on central atom, N. Whereas, N₃,  and CO₂ are sp hybridised with a linear shape.

Q2: Which of the following molecules has the maximum dipole moment ?    (NEET / AIPMT 2014)
(a) NH₃
(b) NF₃
(c) CO₂
(d) CH₄
Ans: (a)

In NH₃, H is less electronegative than N and hence dipoie moment of each N - H bond is towards N and create high net dipole moment whereas in NF₃ ,F is more electronegative than N, the dipole moment of each N - F bond is opposite to that of lone pair, hence reducing the net dipole moment.