Chemical Bonding · JEE Main previous year questions

2025 17 questions

1. Q622025 · 8 Apr 2025 · Shift 2

   Given below are two statements: \textbf{Statement I}: ${\mathrm{H}}_2\mathrm{Se}$ is more acidic than ${\mathrm{H}}_2\mathrm{Te}$ \textbf{Statement II}: ${\mathrm{H}}_2\mathrm{Se}$ has higher bond enthalpy for dissociation than ${\mathrm{H}}_2\mathrm{Te}$ In the light of the above statements, choose the $\underline{\text{correct}}$ answer from the options given below:

   1. A.Both Statement I and Statement II are true
   2. B.Statement I is true but Statement II is false
   3. C.Both Statement I and Statement II are false
   4. D.Statement I is false but Statement II is true
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   Answer: D

2. Q602025 · 4 Apr 2025 · Shift 1

   Given below are two statements. Statement I: The dipole moment of $\stackrel{4}{\mathrm{C}}{\mathrm{H}}_3-\stackrel{3}{\mathrm{C}}\mathrm{H}=\stackrel{2}{\mathrm{C}}\mathrm{H}-\stackrel{1}{\mathrm{C}}\mathrm{H}=\mathrm{O}$ is greater than $\stackrel{4}{\mathrm{C}}{\mathrm{H}}_3-\stackrel{3}{\mathrm{C}}{\mathrm{H}}_2-\stackrel{2}{\mathrm{C}}{\mathrm{H}}_2-\stackrel{1}{\mathrm{C}}\mathrm{H}=\mathrm{O}$ Statement II: ${\mathrm{C}}_1-{\mathrm{C}}_2$ bond length of $\underset{4}{\mathrm{C}}{\mathrm{H}}_3-\underset{3}{\mathrm{C}}\mathrm{H}=\underset{2}{\mathrm{C}}\mathrm{H}-\underset{1}{\mathrm{C}}\mathrm{H}=\mathrm{O}$ is greater than ${\mathrm{C}}_1-{\mathrm{C}}_2$ bond length of $\underset{4}{\mathrm{C}}{\mathrm{H}}_3-\underset{3}{\mathrm{C}}{\mathrm{H}}_2-\underset{2}{\mathrm{C}}{\mathrm{H}}_2-\underset{1}{\mathrm{C}}\mathrm{H}=\mathrm{O}$ In the light of the above statements, choose the correct answer from the options given below:

   1. A.Both Statement I and Statement II are true
   2. B.Statement I is true but Statement II is false
   3. C.Statement I is false but Statement II is true
   4. D.Both Statement I and Statement II are false
   Show answer

   Answer: B

3. Q672025 · 4 Apr 2025 · Shift 1

   Which of the following molecule(s) show/s paramagnetic behavior? A. ${\mathrm{O}}_2$ B. ${\mathrm{N}}_2$ C. ${\mathrm{F}}_2$ D. ${\mathrm{S}}_2$ E. $\mathrm{C}{\mathrm{l}}_2$ Choose the correct answer from the options given below:

   1. A.A & C only
   2. B.A & E Only
   3. C.A & D Only
   4. D.B Only
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   Answer: C

4. Q732025 · 4 Apr 2025 · Shift 2· Numerical answer

   A metal complex with a formula ${\mathrm{MCl}}_4\cdot 3{\mathrm{NH}}_3$ is involved in ${\mathrm{sp}}^3{\mathrm{d}}^2$ hybridisation. It upon reaction with excess of ${\mathrm{AgNO}}_3$ solution gives ' $x$ ' moles of $\mathrm{AgCl}$. Consider ' $x$ ' is equal to the number of lone pairs of electron present in central atom of ${\mathrm{BrF}}_5$. Then the number of geometrical isomers exhibited by the complex is $\underline{}$.

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   Answer: 2

5. Q542025 · 3 Apr 2025 · Shift 1

   Match the LIST-I with LIST-II $$\begin{array}{ll}\text{LIST-I}& \text{LIST-II}\\ \text{(Molecules/ion)}& \text{(Hybridisation of central atom)}\\ \text{A.}\mathrm{P}{\mathrm{F}}_5& \text{I}\mathrm{ds}{\mathrm{p}}^2\\ \text{B}\mathrm{S}{\mathrm{F}}_6& \text{II}\mathrm{s}{\mathrm{p}}^3\mathrm{d}\\ \text{C}\mathrm{Ni}(\mathrm{CO}{)}_4& \text{III}\mathrm{s}{\mathrm{p}}^3{\mathrm{d}}^2\\ \text{D}[\mathrm{PtC}{\mathrm{l}}_4{]}^{2-}& \text{IV}\mathrm{s}{\mathrm{p}}^3\end{array}$$ Choose the correct answer from the options given below:

   1. A.A-IV, B-I, C-II, D-III
   2. B.A-III, B-I, C-IV, D-II
   3. C.A-II, B-III, C-IV, D-I
   4. D.A-I, B-II, C-III, D-IV
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   Answer: C

6. Q642025 · 2 Apr 2025 · Shift 1

   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 nonzero dipole moment and highest number of lone-pairs of electrons on the central atom is

   1. A.${\mathrm{sp}}^3$
   2. B.${\mathrm{dsp}}^2$
   3. C.${\mathrm{sp}}^3{\mathrm{d}}^2$
   4. D.${\mathrm{sp}}^3\mathrm{d}$
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   Answer: D

7. Q552025 · 2 Apr 2025 · Shift 2

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

   1. A.$\mathrm{Xe}{\mathrm{F}}_4$
   2. B.$\mathrm{Xe}{\mathrm{F}}_2$
   3. C.$\mathrm{P}{\mathrm{F}}_5$
   4. D.$\mathrm{S}{\mathrm{F}}_4$
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   Answer: D

8. Q562025 · 2 Apr 2025 · Shift 2

   In 3,3-dimethylhex-1-en-4-yne, there are ____ $\mathrm{s}{\mathrm{p}}^3$, ____ $\mathrm{s}{\mathrm{p}}^2$ and ____ $\mathrm{sp}$ hybridised carbon atoms respectively.

   1. A.4, 2, 2
   2. B.2, 4, 2
   3. C.3, 3, 2
   4. D.2, 2, 4
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   Answer: A

9. Q672025 · 2 Apr 2025 · Shift 2

   The type of hybridization and the magnetic property of $[\mathrm{MnC}{\mathrm{l}}_6{]}^{3-}$ are,

   1. A.$s{p}^3{d}^2$, paramagnetic with four unpaired electrons.
   2. B.$d^{2}s{p}^3$, paramagnetic with four unpaired electrons.
   3. C.$s{p}^3{d}^2$, paramagnetic with two unpaired electrons.
   4. D.$d^{2}s{p}^3$, paramagnetic with two unpaired electrons.
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   Answer: A

10. Q672025 · 29 Jan 2025 · Shift 2

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

    1. A.14 and 3
    2. B.11 and 3
    3. C.13 and 3
    4. D.3 and 13
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    Answer: C

11. Q642025 · 28 Jan 2025 · Shift 1

    Consider ' n ' is the number of lone pair of electrons present in the equatorial position of the most stable structure of $\mathrm{Cl}{\mathrm{F}}_3$. The ions from the following with ' n ' number of unpaired electrons are A. ${\mathrm{V}}^{3+}$ B. $\mathrm{T}{\mathrm{i}}^{3+}$ C. $\mathrm{C}{\mathrm{u}}^{2+}$ D. $\mathrm{N}{\mathrm{i}}^{2+}$ E. $\mathrm{T}{\mathrm{i}}^{2+}$ Choose the correct answer from the options given below:

    1. A.B and D Only
    2. B.A, D and E Only
    3. C.B and C Only
    4. D.A and C Only
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    Answer: B

12. Q672025 · 28 Jan 2025 · Shift 1
    
    1. A.Both Statement I and Statement II are correct
    2. B.Statement I is incorrect but Statement II is correct
    3. C.Both Statement I and Statement II are incorrect
    4. D.Statement I is correct but Statement II is incorrect
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    Answer: A

13. Q712025 · 28 Jan 2025 · Shift 1· Numerical answer

    The formation enthalpies, $\Delta {\mathrm{H}}_{\mathrm{f}}^{\ominus }$ for ${\mathrm{H}}_{(\mathrm{g})}$ and ${\mathrm{O}}_{(\mathrm{g})}$ are $220.0$ and $250.0\mathrm{kJ}\mathrm{mo}{\mathrm{l}}^{-1}$, respectively, at $298.15\mathrm{K}$ , and $\Delta {\mathrm{H}}_{\mathrm{f}}^{\ominus }$ for ${\mathrm{H}}_2{\mathrm{O}}_{(\mathrm{g})}$ is $-242.0\mathrm{kJ}\mathrm{mo}{\mathrm{l}}^{-1}$ at the same temperature. The average bond enthalpy of the $\mathrm{O}-\mathrm{H}$ bond in water at $298.15\mathrm{K}$ is ____ $\mathrm{kJ}\mathrm{mo}{\mathrm{l}}^{-1}$ (nearest integer).

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    Answer: 466

14. Q632025 · 24 Jan 2025 · Shift 1

    Which of the following statement is true with respect to ${\mathrm{H}}_2\mathrm{O}$, $\mathrm{N}{\mathrm{H}}_3$ and $\mathrm{C}{\mathrm{H}}_4$ ? A. The central atoms of all the molecules are $\mathrm{s}{\mathrm{p}}^3$ hybridized. B. The $\mathrm{H}-\mathrm{O}-\mathrm{H}$, $\mathrm{H}-\mathrm{N}-\mathrm{H}$ and $\mathrm{H}-\mathrm{C}-\mathrm{H}$ angles in the above molecules are $104.5^{\circ }$ , $107.5^{\circ }$ and $109.5^{\circ }$ , respectively. C. The increasing order of dipole moment is $\mathrm{C}{\mathrm{H}}_4<\mathrm{N}{\mathrm{H}}_3<{\mathrm{H}}_2\mathrm{O}$. D. Both ${\mathrm{H}}_2\mathrm{O}$ and $\mathrm{N}{\mathrm{H}}_3$ are Lewis acids and $\mathrm{C}{\mathrm{H}}_4$ is a Lewis base. E. A solution of $\mathrm{N}{\mathrm{H}}_3$ in ${\mathrm{H}}_2\mathrm{O}$ is basic. In this solution $\mathrm{N}{\mathrm{H}}_3$ and ${\mathrm{H}}_2\mathrm{O}$ act as Lowry-Bronsted acid and base respectively. Choose the correct answer from the options given below:

    1. A.A, D and E Only
    2. B.C, D and E Only
    3. C.A, B and C Only
    4. D.A, B, C and E Only
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    Answer: C

15. Q622025 · 24 Jan 2025 · Shift 2
    
    1. A.3 and 5
    2. B.3 and 6
    3. C.4 and 5
    4. D.4 and 6
    Show answer

    Answer: A

16. Q662025 · 24 Jan 2025 · Shift 2

    Given below are two statements : Statement (I) : Experimentally determined oxygen-oxygen bond lengths in the ${\mathrm{O}}_3$ are found to be same and the bond length is greater than that of a $\mathrm{O}=\mathrm{O}$ (double bond) but less than that of a single $(\mathrm{O}-\mathrm{O})$ 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 $(\mathrm{O}=\mathrm{O})$ but more than that of a single bond $(\mathrm{O}-\mathrm{O})$. In the light of the above statements, choose the correct answer from the options given below :

    1. A.Statement I is false but Statement II is true
    2. B.Both Statement I and Statement II are true
    3. C.Statement I is true but Statement II is false
    4. D.Both Statement I and Statement II are false
    Show answer

    Answer: C

17. Q542025 · 22 Jan 2025 · Shift 1

    From the magnetic behaviour of $[{\mathrm{NiCl}}_4{]}^{2-}$ (paramagnetic) and $[\mathrm{Ni}(\mathrm{CO}{)}_4]$ (diamagnetic), choose the correct geometry and oxidation state.

    1. A.$[{\mathrm{NiCl}}_4{]}^{2-}:\mathrm{Ni}(0)\text{, tetrahedral }[\mathrm{Ni}(\mathrm{CO}{)}_4]:\mathrm{Ni}(0)\text{, square planar}$
    2. B.$[{\mathrm{NiCl}}_4{]}^{2-}:{\mathrm{Ni}}^{\mathrm{II}}\text{, tetrahedral }[\mathrm{Ni}(\mathrm{CO}{)}_4]:\mathrm{Ni}(0)\text{, tetrahedral}$
    3. C.$[{\mathrm{NiCl}}_4{]}^{2-}:{\mathrm{Ni}}^{\mathrm{II}}\text{, tetrahedral }[\mathrm{Ni}(\mathrm{CO}{)}_4]:{\mathrm{Ni}}^{II}\text{, square planar}$
    4. D.$[{\mathrm{NiCl}}_4{]}^{2-}:{\mathrm{Ni}}^{\mathrm{II}}\text{, square planar }[\mathrm{Ni}(\mathrm{CO}{)}_4]:\mathrm{Ni}(0)\text{, square planar}$
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    Answer: B