BoardChemistry

Chemical Bonding and Molecular Structure

22 Board Chemistry previous year questions on Chemical Bonding and Molecular Structure — options free on every question; 2 include the answer & explanation free, the rest unlock with PYQ Pass.

Q1 FREE PREVIEW
PYQ

Which of the following has non-zero dipole moment value?

[Re-NEET 2024]

a

\({\mathrm{CCl}}_{4}\)

b

\(\mathrm{HI}\)

c

\({\mathrm{CO}}_{2}\)

d

\({\mathrm{BF}}_{3}\)

✓ Correct answer: b)

\(\mathrm{HI}\)

Explanation

HI has a non-zero dipole moment value due to electronegativity difference

Q2 FREE PREVIEW
PYQ

In \({\mathrm{SO}}_{2},{\mathrm{NO}}_{2}^{-}\) and \({\mathrm{N}}_{3}^{-}\)the hybridisations at the central atom are, respectively,

a

\({\mathrm{sp}}^{2},{\mathrm{sp}}^{2}\) and sp

b

\({\mathrm{sp}}^{2}\), sp and sp

c

\({\mathrm{sp}}^{2},{\mathrm{sp}}^{2}\) and \({\mathrm{sp}}^{2}\)

d

\(\mathrm{sp},{\mathrm{sp}}^{2}\) and sp

✓ Correct answer: a)

\({\mathrm{sp}}^{2},{\mathrm{sp}}^{2}\) and sp

Explanation

Theoretical

Q3
PYQ

Which of the following molecules(s) show/s paramagnetic behavior?
(A) \({\mathrm{O}}_{2}\)
(B) \({\mathrm{N}}_{2}\)
(C) \({\mathrm{F}}_{2}\)
(D) \({\mathrm{S}}_{2}\)
(E) \({\mathrm{Cl}}_{2}\)
Choose the correct answer from the options given below :

a

B only

b

A & C only

c

A & E only

d

A & D only

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Q4
PYQ

Number of \(\sigma \mathrm{and}\pi\) bonds respectively in hex-1-en-4-yne are:

Memory Based Question 29/Jan/25 Evening shift

a

13,3

b

14,3

c

3,14

d

14,13

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Q5
PYQ

The correct statement/s about Hydrogen bonding is/are
A. Hydrogen bonding exists when \(\mathrm{H}\) is covalently bonded to the highly electronegative atom.
B. Intermolecular H bonding is present in o-nitro phenol
C. Intramolecular H bonding is present in \(\mathrm{HF}\)
D. The magnitude of H bonding depends on the physical state of the compound.
E. H-bonding has powerful effect on the structure and properties of compounds

Choose the correct answer from the options given below:

[JEE Main 2024, 4 Apr (Shift 2)]

a

A, B, C only

b

A only

c

A, B, D only

d

A, D, E only

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Q6
PYQ

Total number of lone pair of electron in \( \mathrm{I}_{3}^{-} \)ion is:

a

\(3\)

b

\(6\)

c

\(9\)

d

\(12\)

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Q7
PYQ

Given below are two statements:

Statement-I: Oxygen-oxygen bond length in ozone is greater than dioxygen

Statement-II: \(\mathrm{O}-\mathrm{O}\) bond order in ozone is 1.5 and \(\mathrm{O}-\mathrm{O}\) bond order in dioxygen is 2.0

In the light of the above statements, choose the most appropriate answer from the options given below:

a

Statement I is correct but Statement II is incorrect.

b

Statement I is incorrect but Statement II is correct.

c

Both Statement I and Statement II are correct.

d

Both Statement I and Statement II are incorrect.

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Q8
PYQ

Which of the following linear combination of atomic orbitals will lead to formation of molecular orbitals in homonuclear diatomic molecules [internuclear axis in 𝑧-direction] ?

A. \(2{p}_{z}\) and \(2{p}_{x}\)
B. 2s and \(2{p}_{x}\)
C. \(3{d}_{xy}\) and \(3{d}_{{x}^{2}-{y}^{2}}\)
D. 2s and \(2{p}_{z}\)
E. \(2{p}_{z}\) and \(3{d}_{{x}^{2}-{y}^{2}}\)

a

A and B Only

b

D Only

c

C and D Only

d

E Only

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Q9
PYQ

The hybridisation scheme for the central atom includes a d-orbital contribution in

a

\({\mathrm{I}}_{3}^{-}\)

b

\({\mathrm{PCl}}_{3}\)

c

\({\mathrm{NO}}_{3}^{-}\)

d

\({\mathrm{H}}_{2}\mathrm{Se}\)

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Q10
PYQ

Identify the correct orders against the property mentioned
A. \({\mathrm{H}}_{2}\mathrm{O}>{\mathrm{NH}}_{3}>{\mathrm{CHCl}}_{3}\) - dipole moment
B. \({\mathrm{XeF}}_{4}>{\mathrm{XeO}}_{3}>{\mathrm{XeF}}_{2}\)- number of lone pairs on central atom
C. \(\mathrm{O}-\mathrm{H}>\mathrm{C}-\mathrm{H}>\mathrm{N}-\mathrm{O}\) - bond length
D. \({\mathrm{N}}_{2}>{\mathrm{O}}_{2}>{\mathrm{H}}_{2}-\) bond enthalpy

Choose the correct answer from the options given below :

a

A, C only

b

B, C only

c

A, D only

d

B, D only

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Q11
PYQ

Total number of sigma \((\sigma )\) ______ and \(pi(\pi )\) _______ bonds respectively present in hex-1-en-4-yne are

[JEE Main 2025, 29 Jan (Shift 2)]

a

3 and 13

b

14 and 3

c

11 and 3

d

13 and 3

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Q12
PYQ

The linear combination of atomic orbitals to form molecular orbitals
takes place only when the combining atomic orbitals

A. have the same energy
B. have the minimum overlap
C. have same symmetry about the molecular axis
D. have different symmetry about the molecular axis

Choose the most appropriate from the options given below:

a

A, B, C only

b

A and C only

c

B, C, D only

d

B and D only

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Q13
PYQ

Identify the correct statement.

[NEET 2024]

a

Three canonical forms can be drawn for \(C{O}_{3}^{2-}\) ion.

b

Three resonance structures can be drawn for ozone.

c

\(B{F}_{3}\) has non-zero dipole moment.

d

Dipole moment of \(N{F}_{3}\) is greater than that of \(N{H}_{3}\).

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Q14
PYQ

Which among the following molecules is (a) involved in \({\mathrm{sp}}^{3}\mathrm{d}\) hybridization, (b) has different bond lengths and (c) has lone pair of electrons on the central atom?

[JEE Main 2025, 2 Apr (Shift 2)]

a

\({\mathrm{PF}}_{5}\)

b

\({\mathrm{XeF}}_{4}\)

c

\({\mathrm{SF}}_{4}\)

d

\({\mathrm{XeF}}_{2}\)

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Q15
PYQ

Identify the incorrect statement about \(PCl _5\)

a

\(PCl _5\) possesses two different \(Cl - P - Cl\) bond angles.

b

All five \(P - Cl\) bonds are identical in length.

c

\(PCl _5\) exhibits \(sp ^3 d\) hybridisation.

d

\(PCl _5\) consists of five \(P - Cl\) (sigma) bonds.

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Q16
PYQ

Given below are two statements:

Statement-I: Oxygen-oxygen bond length in ozone is greater than dioxygen

Statement-II: \(\mathrm{O}-\mathrm{O}\) bond order in ozone is 1.5 and \(\mathrm{O}-\mathrm{O}\) bond order in dioxygen is 2.0

In the light of the above statements, choose the most appropriate answer from the options given below:

a

Statement I is correct but Statement II is incorrect.

b

Statement I is incorrect but Statement II is correct.

c

Both Statement I and Statement II are correct.

d

Both Statement I and Statement II are incorrect.

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Q17
PYQ

Arrange the following compounds in increasing order of their dipole moment : \(\mathrm{HBr},{\mathrm{H}}_{2}\mathrm{S},{\mathrm{NF}}_{3}\mathrm{and}{\mathrm{CHCl}}_{3}\)

a

\({\mathrm{H}}_{2}\mathrm{S}<\mathrm{HBr}<{\mathrm{NF}}_{3}<{\mathrm{CHCl}}_{3}\)

b

\({\mathrm{CHCl}}_{3}<{\mathrm{NF}}_{3}<\mathrm{HBr}<{\mathrm{H}}_{2}\mathrm{S}\)

c

\({\mathrm{NF}}_{3}<\mathrm{HBr}<{\mathrm{H}}_{2}\mathrm{S}<{\mathrm{CHCl}}_{3}\)

d

\(\mathrm{HBr}<{\mathrm{H}}_{2}\mathrm{S}<{\mathrm{NF}}_{3}<{\mathrm{CHCl}}_{3}\)

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Q18
PYQ

Given below are two statements :

Statement (I) : According to the Law of Octaves, the elements were arranged in the increasing order of their atomic number.

Statement (II) : Meyer observed a periodically repeated pattern upon plotting physical properties of certain elements against their respective atomic numbers.

In the light of the above statements, choose the correct answer from the options given below:

a

Both Statement I and Statement II are true

b

Statement I is false but Statement II is true

c

Statement I is true but Statement II is false

d

Both Statement I and Statement II are false

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Q19
PYQ

The correct increasing order for bond angles among \(B{F}_{3},P{F}_{3}\) and \(Cl{F}_{3}\) is :

[JEE Main 2024, 9 Apr (Shift 2)]

a

\(Cl{F}_{3}

b

\(B{F}_{3}=P{F}_{3}

c

\(B{F}_{3}

d

\(P{F}_{3}

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Q20
PYQ

Given below are two statements :
Statement (I): Experimentally determined oxygen-oxygen bond lengths in the \({O}_{3}\) are found to be same and the bond length is greater than that of a O = O (double bond) but less than that of a single (O − O) bond.
Statement (II) : The strong lone pair-lone pair repulsion between oxygen atoms is solely responsible for the fact that the bond length in ozone is smaller than that of a double bond (O = O) but more than that of a single bond (O − O).
In the light of the above statements, choose the correct answer from the options given below :

[JEE Main 2025, 24 Jan (Shift 2)]

a

Statement I is false but Statement II is true

b

Both Statement I and Statement II are true

c

Both Statement I and Statement II are false

d

Statement I is true but Statement II is false

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Q21
PYQ

The molecules having square pyramidal geometry are

[JEE Main 2025, 28 Jan (Shift 1)]

a

\(Sb{F}_{5}\&PC{l}_{5}\)

b

\(Sb{F}_{5}\&XeO{F}_{4}\)

c

\(Br{F}_{5}\&PC{l}_{5}\)

d

\(Br{F}_{5}\&XeO{F}_{4}\)

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Q22
PYQ

Among \({\mathrm{SO}}_{2},{\mathrm{NF}}_{3},{\mathrm{NH}}_{3},{\mathrm{XeF}}_{2},{\mathrm{ClF}}_{3}\) and \({\mathrm{SF}}_{4}\), the hybridization of the molecule with non-zero dipole moment and highest number of lone-pairs of electrons on the central atom is

[JEE Main 2025, 2 Apr (Shift 1)]

a

\({\mathrm{sp}}^{3}\)

b

\({\mathrm{dsp}}^{2}\)

c

\({\mathrm{sp}}^{3}{\mathrm{d}}^{2}\)

d

\({\mathrm{sp}}^{3}\mathrm{d}\)

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