Chemical Bonding & Molecular Structure
Identify the pair of molecules in which the hybridisation of the central atom is $s p^2$ with bent geometry.
$\mathrm{H}_2 \mathrm{O}, \mathrm{SO}_2$
$\mathrm{SO}_2, \mathrm{O}_3$
$\mathrm{H}_2 \mathrm{O}, \mathrm{O}_3$
$\mathrm{N}_2 \mathrm{O}, \mathrm{H}_2 \mathrm{O}$
Consider the following statements
I. In the conversion of $\mathrm{O}_2$ to $\mathrm{O}_2^{2+}$ bond order decreases.
II. In the conversion of $\mathrm{O}_2$ to $\mathrm{O}_2^{2+}$ magnetic property is not changed.
III. In the conversion of $\mathrm{O}_2$ to $\mathrm{O}_2^{2+}$ bond length decreases.
IV. $\mathrm{O}_2^{2-}$ and $\mathrm{B}_2$ have same bond order.
Identify the correct statements
I and III only
III and IV only
II and III only
I and IV only
The correct order of increasing bond lengths of $\mathrm{C}-\mathrm{H}$, $\mathrm{O}-\mathrm{H}, \mathrm{C}-\mathrm{C}$ and $\mathrm{H}-\mathrm{H}$ is
$\mathrm{O}-\mathrm{H}<\mathrm{H}-\mathrm{H}<\mathrm{C}-\mathrm{C}<\mathrm{C}-\mathrm{H}$
$\mathrm{C}-\mathrm{C}<\mathrm{C}-\mathrm{H}<\mathrm{H}-\mathrm{H}<\mathrm{O}-\mathrm{H}$
$\mathrm{C}-\mathrm{C}<\mathrm{O}-\mathrm{H}<\mathrm{H}-\mathrm{H}<\mathrm{C}-\mathrm{H}$
The sum of bond order of $\mathrm{O}_2^{2+}, \mathrm{O}_2^{2-}, \mathrm{O}_2^{+}, \mathrm{O}_2^{-}, \mathrm{O}_2$ and sum of the unpaired electrons present in them respectively are
10,4
10,6
8,4
8,6
$ \text { Which of the following sets are correctly matched? } $
$ \begin{array}{llll} \hline & \text { Molecule } & \text { Hybridisation } & \text { Geometry } \\ \hline \text { I. } & \mathrm{BrF}_5 & s p^3 d^2 & \text { Square pyramidal } \\ \hline \text { II. } & \mathrm{XeF}_6 & s p^3 d^3 & \text { Distorted octahedral } \\ \hline \text { III. } & \mathrm{SF}_4 & d s p^2 & \text { Square planar } \\ \hline \text { IV. } & \mathrm{PbCl}_2 & s p & \text { Linear } \\ \hline \end{array} $
I and IV
II and III
III and IV
I and II
The order of dipole moments of $\mathrm{H}_2 \mathrm{O}(A), \mathrm{CHCl}_3(B)$ and $\mathrm{NH}_3(C)$ is
$ \text { Match the following } $
| $ \begin{gathered} \text { List-I } \\ \text { (Molecule) } \end{gathered} $ |
List-II (Dipole moment in D) |
||
|---|---|---|---|
| (A) | $ \mathrm{HCl} $ |
(I) | 1.85 |
| (B) | $ \mathrm{NH}_3 $ |
(II) | 1.07 |
| (C) | $ \mathrm{H}_2 \mathrm{O} $ |
(III) | 0.23 |
| (D) | $ \mathrm{NF}_3 $ |
(IV) | 1.47 |
The correct answer is
A-II, B-IV, C-I, D-III
A-IV, B-III, C-I, D-II
A-II, B-I, C-IV, D-III
A-III, B-II, C-IV, D-I
$ \text { Which of the following sets are correctly matched? } $
$ \begin{array}{llcc} \hline & \text { Molecule } & \begin{array}{c} \text { Number of lone } \\ \text { pair of electrons } \\ \text { on central atom } \end{array} & \text { Hybridisation } \\ \hline \text { (I) } & \mathrm{PCl}_3 & 1 & s p^3 \\ \hline \text { (II) } & \mathrm{SO}_2 & 2 & s p^3 \\ \hline \text { (III) } & \mathrm{SF}_4 & 2 & s p^3 d^2 \\ \hline \text { (IV) } & \mathrm{ClF}_3 & 2 & s p^3 d \\ \hline \end{array} $
I and II
II and III
II and IV
I and IV
The number of molecules having lone pair of electrons on central atom in the following is
$\mathrm{BF}_3, \mathrm{SF}_4, \mathrm{SiCl}_4, \mathrm{XeF}_4, \mathrm{NCl}_3, \mathrm{XeF}_6, \mathrm{PCl}_5, \mathrm{HgCl}_2, \mathrm{SnCl}_2$
6
3
4
5
Observe the following molecules/ions $\mathrm{NH}_4^{+}, \mathrm{NH}_3, \mathrm{BF}_3, \mathrm{OH}^{-}, \mathrm{CH}_3^{+}, \mathrm{H}^{+}, \mathrm{CO}, \mathrm{C}_2 \mathrm{H}_4$.
The number of Lewis bases in the above list is
2
3
4
5
$\mathrm{XeO}_3, \mathrm{SF}_4$
$\mathrm{BrF}_5, \mathrm{PF}_5$
$\mathrm{ClF}_3, \mathrm{SF}_4$
$\mathrm{PCl}_3, \mathrm{NH}_3$
Identify the set containing isoelectronic species
$\mathrm{N}_2, \mathrm{O}_2^{2-}, \mathrm{NO}^{+}$
$\mathrm{N}_2, \mathrm{CO}, \mathrm{NO}^{+}$
$\mathrm{F}_2, \mathrm{O}_2^{2-}, \mathrm{N}_2$
$\mathrm{N}_2, \mathrm{O}_2^{2+}, \mathrm{C}_2$
A molecules has T -shape. The total number of electron pairs in the valence shell of central atom of it is
4
5
6
3
$\mathrm{O}_2^{-}, \mathrm{O}_2^{+}, \mathrm{O}_2$
$\mathrm{B}_2, \mathrm{~N}_2, \mathrm{~F}_2$
$\mathrm{He}_2^{+}, \mathrm{F}_2, \mathrm{~N}_2$
$\mathrm{O}_2^{2-}, \mathrm{N}_2, \mathrm{Be}_2$
How many of the following molecules have two lone pairs of electrons on central atom?
$\mathrm{SF}_6, \mathrm{BF}_3, \mathrm{ClF}_3, \mathrm{PCl}_5, \mathrm{BrF}_5, \mathrm{XeF}_4, \mathrm{H}_2 \mathrm{O}, \mathrm{SF}_4$
5
4
3
2
The pair of molecules / ions with the same bond order value is
$\mathrm{B}_2, \mathrm{C}_2$
$\mathrm{O}_2, \mathrm{C}_2$
$\mathrm{O}_2^{+}, \mathrm{O}_2^{-}$
$\mathrm{H}_2^{+}, \mathrm{Li}_2$
How many of the following molecules / ions have trigonal planar structure?
$ \mathrm{BO}_3^{3-}, \mathrm{NH}_3, \mathrm{PCl}_3, \mathrm{BCl}_3, \mathrm{ClF}_3, \mathrm{XeO}_3 $
5
2
4
3
Consider the following
Assertion (A) Dipole moment of $\mathrm{NF}_3$ is lesser than $\mathrm{NH}_3$.
Reason (R) In $\mathrm{NF}_3$, the orbital dipole due to lone pair of electrons is in the opposite direction to the resultant dipole moment of the three $\mathrm{N}-\mathrm{F}$ bonds.
The correct answer is
both (A) and (R) are correct and (R) is the correct explanation of (A)
both (A) and (R) are correct but (R) is not the correct explanation of (A)
(A) is correct but (R) is not correct
(A) is not correct but (R) is correct
Consider the following changes I and II
$ \mathrm{O}_2^{-} \underset{\text { II }}{\longleftarrow} \mathrm{O}_2 \xrightarrow[\text { I }]{ } \mathrm{O}_2^{+} $
The correct statements about these changes (I) and (II) in accordance with MO theory are
(A) In (I) bond order increases by 0.5 from the existing value
(B) In (II) bond order decreases by 1.0 from the existing value
(C) In both (I) and (II) magnetic property is not changed
(D) In both (I) and (II) magnetic property is changed
A, B and C only
A and C only
A and D only
B and C only
The increasing order of number of lone pair of electrons on the central atom of the following molecules is
(I) $\mathrm{ClF}_3$
(II) $\mathrm{XeF}_2$
(III) $\mathrm{SF}_4$
(IV) $\mathrm{SiH}_4$
IV $<$ III $<$ II $<$ I
I $<$ II $<$ III $<$ IV
II $<$ I $<$ III $<$ IV
IV $<$ III $<$ I $<$ II
Identify the correct set of molecules with zero dipole moment
$\mathrm{CO}_2, \mathrm{NH}_3, \mathrm{H}_2 \mathrm{O}$
$\mathrm{NH}_3, \mathrm{NF}_3, \mathrm{BF}_3$
$\mathrm{PF}_3, \mathrm{NH}_3, \mathrm{CH}_4$
$\mathrm{CH}_4, \mathrm{BF}_3, \mathrm{CO}_2$
The correct increasing order for bond angles among $\mathrm{BF}_3, \mathrm{PF}_3$ and $\mathrm{ClF}_3$ is :
In which one of the following pairs the central atoms exhibit $\mathrm{sp}^2$ hybridization ?
The shape of carbocation is :
When $\psi_{\mathrm{A}}$ and $\psi_{\mathrm{B}}$ are the wave functions of atomic orbitals, then $\sigma^*$ is represented by :
Match List I with List II
| LIST I (Molecule) |
LIST II (Shape) |
||
|---|---|---|---|
| A. | $\mathrm{NH_3}$ | I. | Square pyramid |
| B. | $\mathrm{BrF_5}$ | II. | Tetrahedral |
| C. | $\mathrm{PCl_5}$ | III. | Trigonal pyramidal |
| D. | $\mathrm{CH_4}$ | IV. | Trigonal bipyramidal |
Choose the correct answer from the options given below:
Match List I with List II
| LIST I (Compound/Species) |
LIST II (Shape/Geometry) |
||
|---|---|---|---|
| A. | $\mathrm{SF_4}$ | I. | Tetrahedral |
| B. | $\mathrm{BrF_3}$ | II. | Pyramidal |
| C. | $\mathrm{BrO_3^-}$ | III. | See saw |
| D. | $\mathrm{NH_4^+}$ | IV. | Bent T-Shape |
Choose the correct answer from the options given below:
Match List I with List II
| LIST I (Molecule/Species) |
LIST II (Property/Shape) |
||
|---|---|---|---|
| A. | $\mathrm{SO_2Cl_2}$ | I. | Paramagnetic |
| B. | $\mathrm{NO}$ | II. | Diamagnetic |
| C. | $\mathrm{NO_2^-}$ | III. | Tetrahedral |
| D. | $\mathrm{I_3^-}$ | IV. | Linear |
Choose the correct answer from the options given below:
Match List I with List II.
| LIST I |
LIST II |
||
|---|---|---|---|
| A. | $ \mathrm{ICl} $ |
I. | T - shape |
| B. | $ \mathrm{ICl}_3 $ |
II. | Square pyramidal |
| C. | $ \mathrm{ClF}_5 $ |
III. | Pentagonal bipyramidal |
| D. | $ \mathrm{IF}_7 $ |
IV. | Linear |
Choose the correct answer from the options given below :
Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A) : $\mathrm{NH}_3$ and $\mathrm{NF}_3$ molecule have pyramidal shape with a lone pair of electrons on nitrogen atom. The resultant dipole moment of $\mathrm{NH}_3$ is greater than that of $\mathrm{NF}_3$.
Reason (R) : In $\mathrm{NH}_3$, the orbital dipole due to lone pair is in the same direction as the resultant dipole moment of the $\mathrm{N}-\mathrm{H}$ bonds. $\mathrm{F}$ is the most electronegative element.
In the light of the above statements, choose the correct answer from the options given below :
Number of $\sigma$ and $\pi$ bonds present in ethylene molecule is respectively :
The correct statement/s about Hydrogen bonding is/are
A. Hydrogen bonding exists when H is covalently bonded to the highly electro negative atom.
B. Intermolecular H bonding is present in $o$-nitro phenol
C. Intramolecular $\mathrm{H}$ bonding is present in HF.
D. The magnitude of $\mathrm{H}$ 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:
The number of species from the following that have pyramidal geometry around the central atom is _________
$\mathrm{S}_2 \mathrm{O}_3^{2-}, \mathrm{SO}_4^{2-}, \mathrm{SO}_3^{2-}, \mathrm{S}_2 \mathrm{O}_7^{2-}$
Number of molecules/ions from the following in which the central atom is involved in $\mathrm{sp}^3$ hybridization is ________.
$\mathrm{NO}_3^{-}, \mathrm{BCl}_3, \mathrm{ClO}_2^{-}, \mathrm{ClO}_3^{-}$
Which one of the following molecules has maximum dipole moment?
Statement (I) : A $\pi$ bonding MO has lower electron density above and below the inter-nuclear axis.
Statement (II) : The $\pi^*$ antibonding MO has a node between the nuclei.
In the light of the above statements, choose the most appropriate answer from the options given below :
Assertion (A): $\mathrm{PH}_3$ has lower boiling point than $\mathrm{NH}_3$.
Reason (R) : In liquid state $\mathrm{NH}_3$ molecules are associated through vander Waal's forces, but $\mathrm{PH}_3$ molecules are associated through hydrogen bonding.
In the light of the above statements, choose the most appropriate answer from the options given below :
Which of the following is least ionic?
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:
Given below are two statements:
Statement - I: Since Fluorine is more electronegative than nitrogen, the net dipole moment of $\mathrm{NF}_3$ is greater than $\mathrm{NH}_3$.
Statement - II: In $\mathrm{NH}_3$, the orbital dipole due to lone pair and the dipole moment of $\mathrm{NH}$ bonds are in opposite direction, but in $\mathrm{NF}_3$ 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:
The molecule / ion with square pyramidal shape is
Aluminium chloride in acidified aqueous solution forms an ion having geometry
Match List I with List II.
| List I Molecule |
List II Shape |
||
|---|---|---|---|
| (A) | $\mathrm{BrF_5}$ | (I) | T-Shape |
| (B) | $\mathrm{H_2O}$ | (II) | See saw |
| (C) | $\mathrm{ClF_3}$ | (III) | Bent |
| (D) | $\mathrm{SF_4}$ | (IV) | Square pyramidal |
Choose the correct answer from the options given below :
Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A) : There is a considerable increase in covalent radius from $\mathrm{N}$ to $\mathrm{P}$. However from As to Bi only a small increase in covalent radius is observed.
Reason (R) : Covalent and ionic radii in a particular oxidation state increases down the group. In the light of the above statements, choose the most appropriate answer from the options given below:
The difference in energy between the actual structure and the lowest energy resonance structure for the given compound is
Choose the polar molecule from the following:
Total number of electrons present in $\left(\pi^*\right)$ molecular orbitals of $\mathrm{O}_2, \mathrm{O}_2^{+}$ and $\mathrm{O}_2^{-}$ is ________.
Explanation:
$\begin{aligned} & \mathrm{O}_2(16 \mathrm{e}):\left(\sigma_{1 \mathrm{~s}}\right)^2\left(\sigma_{1 \mathrm{~s}}^*\right)^2\left(\sigma_{2 \mathrm{~s}}\right)^2\left(\sigma_{2 \mathrm{~s}}^*\right)^2 \\ & \left(\sigma_{2 \mathrm{p}}\right)^2\left[\left(\pi_{2 \mathrm{p}}\right)^2=\left(\pi_{2 \mathrm{p}}\right)^2\right],\left[\left(\pi_{2 \mathrm{p}}^*\right)^1=\left(\pi_{2 \mathrm{p}}^*\right)^1\right] \end{aligned}$
Number of $\mathrm{e}^{-}$ present in $\left(\pi^*\right)$ of $\mathrm{O}_2=2$
Number of $\mathrm{e}^{-}$ present in $\left(\pi^*\right)$ of $\mathrm{O}_2^{+}=1$
Number of $\mathrm{e}^{-}$ present in $\left(\pi^*\right)$ of $\mathrm{O}_2^{-}=3$So total $\mathrm{e}^{-}$ in $\left(\pi^*\right)=2+1+3=6$
The total number of species from the following in which one unpaired electron is present, is _______.
$\mathrm{N}_2, \mathrm{O}_2, \mathrm{C}_2^{-}, \mathrm{O}_2^{-}, \mathrm{O}_2^{2-}, \mathrm{H}_2^{+}, \mathrm{CN}^{-}, \mathrm{He}_2^{+}$
Explanation:
| Species | Unpaired e |
|---|---|
| $ \mathrm{N}_2 $ |
0 |
| $ \mathrm{O}_2 $ |
2 |
| $ \mathrm{C}_2^{-} $ |
1 |
| $ \mathrm{O}_2^{-} $ |
1 |
| $ \mathrm{O}_2^{2-} $ |
0 |
| $ \mathrm{H}_2^{+} $ |
1 |
| $ \mathrm{CN}^{-} $ |
0 |
| $ \mathrm{He}_2^{+} $ |
1 |







