Chemical Bonding · JEE Main previous year questions

The total number of 'sigma' and 'pi' bonds in 2-oxohex-4-ynoic acid is ______.

In case of isoelectronic species the size of ${\mathrm{F}}^{-},\mathrm{Ne}$ and $\mathrm{N}{\mathrm{a}}^{+}$ is affected by :

1. A.Nuclear charge $(\mathrm{z})$
2. B.None of the factors because their size is the same
3. C.Electron-electron interaction in the outer orbitals
4. D.Principal quantum number (n)

Arrange the bonds in order of increasing ionic character in the molecules. $\mathrm{LiF},{\mathrm{K}}_2\mathrm{O},{\mathrm{N}}_2,\mathrm{S}{\mathrm{O}}_2$ and $\mathrm{Cl}{\mathrm{F}}_3$ :

1. A.${\mathrm{N}}_2<\mathrm{S}{\mathrm{O}}_2<\mathrm{Cl}{\mathrm{F}}_3<{\mathrm{K}}_2\mathrm{O}<\mathrm{LiF}$
2. B.$\mathrm{Cl}{\mathrm{F}}_3<{\mathrm{N}}_2<\mathrm{S}{\mathrm{O}}_2<{\mathrm{K}}_2\mathrm{O}<\mathrm{LiF}$
3. C.$\mathrm{LiF}<{\mathrm{K}}_2\mathrm{O}<\mathrm{Cl}{\mathrm{F}}_3<\mathrm{S}{\mathrm{O}}_2<{\mathrm{N}}_2$
4. D.${\mathrm{N}}_2<\mathrm{Cl}{\mathrm{F}}_3<\mathrm{S}{\mathrm{O}}_2<{\mathrm{K}}_2\mathrm{O}<\mathrm{LiF}$

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

A diatomic molecule has a dipole moment of $1.2\mathrm{D}$. If the bond distance is $1{\mathrm{A}}^{\circ }$, then fractional charge on each atom is ____ $\times 10^{-1}$ esu. (Given $1\mathrm{D}=10^{-18}$ esucm)

Diamagnetic Lanthanoid ions are :

1. A.$\mathrm{L}{\mathrm{a}}^{3+}\&\mathrm{C}{\mathrm{e}}^{4+}$
2. B.$\mathrm{N}{\mathrm{d}}^{3+}\&\mathrm{C}{\mathrm{e}}^{4+}$
3. C.$\mathrm{L}{\mathrm{u}}^{3+}\&\mathrm{E}{\mathrm{u}}^{3+}$
4. D.$\mathrm{N}{\mathrm{d}}^{3+}\&\mathrm{E}{\mathrm{u}}^{3+}$

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A) : $\mathrm{C}{\mathrm{H}}_2=\mathrm{CH}-\mathrm{C}{\mathrm{H}}_2-\mathrm{Cl}$ is an example of allyl halide. Reason (R) : Allyl halides are the compounds in which the halogen atom is attached to $\mathrm{s}{\mathrm{p}}^2$ hybridised carbon atom. In the light of the above statements, choose the most appropriate answer from the options given below :

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

The difference in energy between the actual structure and the lowest energy resonance structure for a given compound is

1. A.electromeric energy
2. B.resonance energy
3. C.ionization energy
4. D.hyperconjugation energy

The interaction between $\pi$ bond and lone pair of electrons present on an adjacent atom is responsible for

1. A.Resonance effect
2. B.Electromeric effect
3. C.Hyperconjugation
4. D.Inductive effect

The number of species from the following which are paramagnetic and with bond order equal to one is _________. ${\mathrm{H}}_2,\mathrm{H}{\mathrm{e}}_2^{+},{\mathrm{O}}_2^{+},{\mathrm{N}}_2^{2-},{\mathrm{O}}_2^{2-},{\mathrm{F}}_2,\mathrm{N}{\mathrm{e}}_2^{+},{\mathrm{B}}_2$

Number of compounds with one lone pair of electrons on central atom amongst following is _________. ${\mathrm{O}}_3,{\mathrm{H}}_2\mathrm{O},\mathrm{S}{\mathrm{F}}_4,\mathrm{Cl}{\mathrm{F}}_3,\mathrm{N}{\mathrm{H}}_3,\mathrm{Br}{\mathrm{F}}_5,\mathrm{Xe}{\mathrm{F}}_4$

Which of the following statements are correct about $\mathrm{Zn},\mathrm{Cd}$ and $\mathrm{Hg}$ ? A. They exhibit high enthalpy of atomization as the d-subshell is full. B. $\mathrm{Zn}$ and $\mathrm{Cd}$ do not show variable oxidation state while $\mathrm{Hg}$ shows $+\mathrm{I}$ and $+\mathrm{II}$. C. Compounds of $\mathrm{Zn},\mathrm{Cd}$ and $\mathrm{Hg}$ are paramagnetic in nature. D. $\mathrm{Zn},\mathrm{Cd}$ and $\mathrm{Hg}$ are called soft metals. Choose the most appropriate from the options given below:

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

The total number of molecules with zero dipole moment among $\mathrm{C}{\mathrm{H}}_4,\mathrm{B}{\mathrm{F}}_3,{\mathrm{H}}_2\mathrm{O},\mathrm{HF},\mathrm{N}{\mathrm{H}}_3,\mathrm{C}{\mathrm{O}}_2$ and $\mathrm{S}{\mathrm{O}}_2$ is _________.

The total number of 'Sigma' and 'Pi' bonds in 2-formylhex-4-enoic acid is _________.

Sum of bond order of $\text{CO}$ and ${\text{NO}}^{+}$ is _______.

Identify from the following species in which ${\text{d}}^2{\text{sp}}^3$ hybridization is shown by central atom :

1. A.$[\text{Co}({\text{NH}}_3{)}_6{]}^{3+}$
2. B.${\text{SF}}_6$
3. C.$[\text{Pt}({\text{Cl}}_4){]}^{2-}$
4. D.${\text{BrF}}_5$

In which of the following processes, the bond order increases and paramagnetic character changes to diamagnetic one ?

1. A.${\mathrm{O}}_2\to {\mathrm{O}}_2^{2-}$
2. B.${\mathrm{N}}_2\to {\mathrm{N}}_2^{+}$
3. C.$\mathrm{NO}\to {\mathrm{NO}}^{+}$
4. D.${\mathrm{O}}_2\to {\mathrm{O}}_2^{+}$

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

${\mathrm{A}}_2+{\mathrm{B}}_2\to 2\mathrm{AB}$. $\Delta H_f^0=-200{\text{ kJ mol}}^{-1}$ $\mathrm{AB}$, ${\mathrm{A}}_2$ and ${\mathrm{B}}_2$ are diatomic molecules. If the bond enthalpies of ${\mathrm{A}}_2$, ${\mathrm{B}}_2$ and $\mathrm{AB}$ are in the ratio $1:0.5:1$, then the bond enthalpy of ${\mathrm{A}}_2$ is ___________ ${\text{kJ mol}}^{-1}$ (Nearest integer)

Given below are two statements : Statement I : ${\mathrm{SO}}_2$ and ${\mathrm{H}}_2\mathrm{O}$ both possess V-shaped structure. Statement II : The bond angle of ${\mathrm{SO}}_2$ is less than that of ${\mathrm{H}}_2\mathrm{O}$. In the light of the above statements, choose the most appropriate answer from the options given below:

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

The bond order and magnetic property of acetylide ion are same as that of

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

In an oligopeptide named Alanylglycylphenyl alanyl isoleucine, the number of ${\mathrm{sp}}^2$ hybridised carbons is _________.

The maximum number of lone pairs of electrons on the central atom from the following species is _________. $\mathrm{Cl}{\mathrm{O}}_3^{-}$, $\mathrm{Xe}{\mathrm{F}}_4$, $\mathrm{S}{\mathrm{F}}_4$ and ${\mathrm{I}}_3^{-}$

The pair from the following pairs having both compounds with net non-zero dipole moment is

1. A.cis-butene, trans-butene
2. B.${\text{CH}}_2{\text{Cl}}_2,{\text{CHCl}}_3$
3. C.Benzene, anisidine
4. D.1,4-Dichlorobenzene, 1,3-Dichlorobenzene

The sum of lone pairs present on the central atom of the interhalogen ${\text{IF}}_5$ and ${\text{IF}}_7$ is _________