Chemical Bonding · JEE Main previous year questions

The number of molecules from the following which contain only two lone pair of electrons is _________ ${\text{H}}_2\text{O},{\text{N}}_2,\text{CO},{\text{XeF}}_4,{\text{NH}}_3,\text{NO},{\text{CO}}_2,{\text{F}}_2$

The number of species from the following carrying a single lone pair on central atom Xenon is ____. $\mathrm{Xe}{\mathrm{F}}_5^{+}$, $\mathrm{Xe}{\mathrm{O}}_3$, $\mathrm{Xe}{\mathrm{O}}_2{\mathrm{F}}_2$, $\mathrm{Xe}{\mathrm{F}}_5^{-}$, $\mathrm{Xe}{\mathrm{O}}_3{\mathrm{F}}_2$, $\mathrm{XeO}{\mathrm{F}}_4$, $\mathrm{Xe}{\mathrm{F}}_4$

The ratio of sigma and $\pi$ bonds present in pyrophosphoric acid is ____.

In an ice crystal, each water molecule is hydrogen bonded to ____________ neighbouring molecules.

For ${\mathrm{OF}}_2$ molecule consider the following : A. Number of lone pairs on oxygen is 2 . B. FOF angle is less than $104.5^{\circ }$. C. Oxidation state of O is $-2$. D. Molecule is bent 'V' shaped. E. Molecular geometry is linear. correct options are:

1. A.A, C, D only
2. B.A, B, D only
3. C.C, D, E only
4. D.B, E, A only

Match List I with List II | List I (molecules/ions) | List II (No. of lone pairs of $e^{-}$ on central atom) | | :--- | :--- | | A. ${\mathrm{IF}}_7$ | I. Three | | B. ${\mathrm{ICl}}_4^{-}$ | II. One | | C. ${\mathrm{XeF}}_6$ | III. Two | | D. ${\mathrm{XeF}}_2$ | IV. Zero | Choose the correct answer from the options given below :

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

According to MO theory the bond orders for ${\mathrm{O}}_2^{2-}$, $\mathrm{CO}$ and ${\mathrm{NO}}^{+}$ respectively, are

1. A.1, 3 and 3
2. B.2, 3 and 3
3. C.1, 2 and 3
4. D.1, 3 and 2

Statement I : Dipole moment is a vector quantity and by convention it is depicted by a small arrow with tail on the negative centre and head pointing towards the positive centre. Statement II : The crossed arrow of the dipole moment symbolizes the direction of the shift of charges in the molecules. In the light of the above statements, choose the most appropriate answer from the options given below :

1. A.Statement I is correct but Statement II is incorrect
2. B.Statement I is incorrect but Statement II is correct
3. C.Both Statement I and Statement II are correct
4. D.Both Statement I and Statement II are incorrect

Decreasing order of the hydrogen bonding in following forms of water is correctly represented by A. Liquid water B. Ice C. Impure water Choose the correct answer from the options given below :

1. A.A = B > C
2. B.B > A > C
3. C.A > B > C
4. D.C > B > A

Number of lone pairs of electrons in the central atom of $\mathrm{SC}{\mathrm{l}}_2$, ${\mathrm{O}}_3$, $\mathrm{Cl}{\mathrm{F}}_3$ and $\mathrm{S}{\mathrm{F}}_6$, respectively, are :

1. A.0, 1, 2 and 2
2. B.2, 1, 2 and 0
3. C.1, 2, 2 and 0
4. D.2, 1, 0 and 2

Consider, $\mathrm{P}{\mathrm{F}}_5$, $\mathrm{Br}{\mathrm{F}}_5$, $\mathrm{PC}{\mathrm{l}}_3$, $\mathrm{S}{\mathrm{F}}_6$, $[\mathrm{IC}{\mathrm{l}}_4{]}^{-}$, $\mathrm{Cl}{\mathrm{F}}_3$ and $\mathrm{I}{\mathrm{F}}_5$. Amongst the above molecule(s)/ion(s), the number of molecule(s)/ion(s) having $\mathrm{s}{\mathrm{p}}^3{\mathrm{d}}^2$ hybridisation is ____.

The number of paramagnetic species among the following is _________. ${\text{B}}_2$, ${\text{Li}}_2$, ${\text{C}}_2$, ${\text{C}}_2^{-}$, ${\text{O}}_2^{2-}$, ${\text{O}}_2^{+}$ and ${\text{He}}_2^{+}$

Which of the following pair is not isoelectronic species? (At. no. $\mathrm{Sm},62;\mathrm{Er},68;\mathrm{Yb},70;\mathrm{Lu},71;\mathrm{Eu},63;\mathrm{Tb},65;\mathrm{Tm},69$)

1. A.$\mathrm{S}{\mathrm{m}}^{2+}$ and $\mathrm{E}{\mathrm{r}}^{3+}$
2. B.$\mathrm{Y}{\mathrm{b}}^{2+}$ and $\mathrm{L}{\mathrm{u}}^{3+}$
3. C.$\mathrm{E}{\mathrm{u}}^{2+}$ and $\mathrm{T}{\mathrm{b}}^{4+}$
4. D.$\mathrm{T}{\mathrm{b}}^{2+}$ and $\mathrm{T}{\mathrm{m}}^{4+}$

Amongst the following, the number of oxide(s) which are paramagnetic in nature is $\mathrm{N}{\mathrm{a}}_2\mathrm{O},\mathrm{K}{\mathrm{O}}_2,\mathrm{N}{\mathrm{O}}_2,{\mathrm{N}}_2\mathrm{O},\mathrm{Cl}{\mathrm{O}}_2,\mathrm{NO},\mathrm{S}{\mathrm{O}}_2,\mathrm{C}{\mathrm{l}}_2\mathrm{O}$

According to MO theory, number of species/ions from the following having identical bond order is _________. ${\mathrm{CN}}^{-},{\mathrm{NO}}^{+},{\mathrm{O}}_2,{\mathrm{O}}_2^{+},{\mathrm{O}}_2^{2+}$

Match List I with List II: | List I (molecule) | List II (hybridization ; shape) | | :--- | :--- | | (A) $\mathrm{Xe}{\mathrm{O}}_3$ | (I) $\mathrm{s}{\mathrm{p}}^3\mathrm{d}$ ; linear | | (B) $\mathrm{Xe}{\mathrm{F}}_2$ | (II) $\mathrm{s}{\mathrm{p}}^3$ ; pyramidal | | (C) $\mathrm{XeO}{\mathrm{F}}_4$ | (III) $\mathrm{s}{\mathrm{p}}^3{\mathrm{d}}^3$ ; distorted octahedral | | (D) $\mathrm{Xe}{\mathrm{F}}_6$ | (IV) $\mathrm{s}{\mathrm{p}}^3{\mathrm{d}}^2$ ; square pyramidal | Choose the correct answer from the options given below:

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

The sum of number of lone pairs of electrons present on the central atoms of $\mathrm{Xe}{\mathrm{O}}_3$, $\mathrm{XeO}{\mathrm{F}}_4$ and $\mathrm{Xe}{\mathrm{F}}_6$, is ____ .

Amongst the following, the number of molecule/(s) having net resultant dipole moment is ___________. $\mathrm{N}{\mathrm{F}}_3$, $\mathrm{B}{\mathrm{F}}_3$, $\mathrm{Be}{\mathrm{F}}_2$, $\mathrm{CHC}{\mathrm{l}}_3$, ${\mathrm{H}}_2\mathrm{S}$, $\mathrm{Si}{\mathrm{F}}_4$, $\mathrm{CC}{\mathrm{l}}_4$, $\mathrm{P}{\mathrm{F}}_5$

In the structure of $\mathrm{S}{\mathrm{F}}_4$, the lone pair of electrons on S is in.

1. A.equatorial position and there are two lone pair - bond pair repulsions at $90^{\circ }$.
2. B.equatorial position and there are three lone pair - bond pair repulsions at $90^{\circ }$.
3. C.axial position and there are three lone pair - bond pair repulsion at $90^{\circ }$.
4. D.axial position and there are two lone pair - bond pair repulsion at $90^{\circ }$.

Based upon VSEPR theory, match the shape (geometry) of the molecules in List-I with the molecules in List-II and select the most appropriate option. $$\begin{array}{llll}& \text{List - I (Shape)}& & \text{List - II (Molecules)}\\ \text{(A)}& \text{T-shaped}& \text{(I)}& \mathrm{Xe}{\mathrm{F}}_4\\ \text{(B)}& \text{Trigonal planar}& \text{(II)}& \mathrm{S}{\mathrm{F}}_4\\ \text{(C)}& \text{Square planar}& \text{(III)}& \mathrm{Cl}{\mathrm{F}}_3\\ \text{(D)}& \text{See-saw}& \text{(IV)}& \mathrm{B}{\mathrm{F}}_3\end{array}$$

1. A.(A) - (I), (B) - (II), (C) - (III), (D) - (IV)
2. B.(A) - (III), (B) - (IV), (C) - (I), (D) - (II)
3. C.(A) - (III), (B) - (IV), (C) - (II), (D) - (I)
4. D.(A) - (IV), (B) - (III), (C) - (I), (D) - (II)

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A) : The ionic radii of ${\mathrm{O}}^{2-}$ and $\mathrm{M}{\mathrm{g}}^{2+}$ are same. Reason (R) : Both ${\mathrm{O}}^{2-}$ and $\mathrm{M}{\mathrm{g}}^{2+}$ are isoelectronic species. In the light of the above statements, choose the correct answer from the options given below.

1. A.Both (A) and (R) are true and (R) is the correct explanation of (A).
2. B.Both (A) and (R) are true but (R) is not the correct explanation of (A).
3. C.(A) is true but (R) is false.
4. D.(A) is false but (R) is true.

The number of statements correct from the following for Copper (at. no. 29) is/are ____________. (A) Cu(II) complexes are always paramagnetic. (B) Cu(I) complexes are generally colourless (C) Cu(I) is easily oxidized (D) In Fehling solution, the active reagent has Cu(I)

The correct order of increasing intermolecular hydrogen bond strength is :

1. A.$\text{HCN}<{\text{H}}_2\text{O}<{\text{NH}}_3$
2. B.$\text{HCN}<{\text{CH}}_4<{\text{NH}}_3$
3. C.${\text{CH}}_4<\text{HCN}<{\text{NH}}_3$
4. D.${\text{CH}}_4<{\text{NH}}_3<\text{HCN}$

Consider the ions/molecule ${\mathrm{O}}_2^{+}$, ${\mathrm{O}}_2$, ${\mathrm{O}}_2^{-}$, ${\mathrm{O}}_2^{2-}$ For increasing bond order the correct option is :

1. A.${\mathrm{O}}_2^{2-}<{\mathrm{O}}_2^{-}<{\mathrm{O}}_2<{\mathrm{O}}_2^{+}$
2. B.${\mathrm{O}}_2^{-}<{\mathrm{O}}_2^{2-}<{\mathrm{O}}_2<{\mathrm{O}}_2^{+}$
3. C.${\mathrm{O}}_2^{-}<{\mathrm{O}}_2^{2-}<{\mathrm{O}}_2^{+}<{\mathrm{O}}_2$
4. D.${\mathrm{O}}_2^{-}<{\mathrm{O}}_2^{+}<{\mathrm{O}}_2^{2-}<{\mathrm{O}}_2$