Chemical Bonding · JEE Advanced previous year questions

The pair(s) of diamagnetic ions is(are)

1. A.$\mathrm{L}{\mathrm{a}}^{3+},\mathrm{C}{\mathrm{e}}^{4+}$
2. B.$\mathrm{Y}{\mathrm{b}}^{2+},\mathrm{L}{\mathrm{u}}^{3+}$
3. C.$\mathrm{L}{\mathrm{a}}^{2+},\mathrm{C}{\mathrm{e}}^{3+}$
4. D.$\mathrm{Y}{\mathrm{b}}^{3+},\mathrm{L}{\mathrm{u}}^{2+}$

For the reaction sequence given below, the correct statement(s) is(are) Cyclohexene $\stackrel{\text{HBr}}{\to }$ $\mathbf{P}$; $\mathbf{P}$ $\stackrel{\text{Finkelstein reaction}}{\to }$ $\mathbf{Q}$; $\mathbf{P}$ $\stackrel{\text{Swarts reaction}}{\to }$ $\mathbf{R}$ (In the options, X is any atom other than carbon and hydrogen, and it is different in $\mathbf{P}$, $\mathbf{Q}$ and $\mathbf{R}$)

1. A.C–X bond length in $\mathbf{P}$, $\mathbf{Q}$ and $\mathbf{R}$ follows the order $\mathbf{Q}>\mathbf{R}>\mathbf{P}$.
2. B.C–X bond enthalpy in $\mathbf{P}$, $\mathbf{Q}$ and $\mathbf{R}$ follows the order $\mathbf{R}>\mathbf{P}>\mathbf{Q}$.
3. C.Relative reactivity toward ${\mathrm{S}}_{\mathrm{N}}2$ reaction in $\mathbf{P}$, $\mathbf{Q}$ and $\mathbf{R}$ follows the order $\mathbf{P}>\mathbf{R}>\mathbf{Q}$.
4. D.$\mathrm{p}{K}_{\mathrm{a}}$ value of the conjugate acids of the leaving groups in $\mathbf{P}$, $\mathbf{Q}$ and $\mathbf{R}$ follows the order $\mathbf{R}>\mathbf{Q}>\mathbf{P}$.

The correct statement(s) about intermolecular forces is(are)

1. A.The potential energy between two point charges approaches zero more rapidly than the potential energy between a point dipole and a point charge as the distance between them approaches infinity.
2. B.The average potential energy of two rotating polar molecules that are separated by a distance $r$ has $1/r^3$ dependence.
3. C.The dipole-induced dipole average interaction energy is independent of temperature.
4. D.Nonpolar molecules attract one another even though neither has a permanent dipole moment.

Based on $\text{VSEPR}$ model, match the xenon compounds given in $\text{List-I}$ with the corresponding geometries and the number of lone pairs on xenon given in $\text{List-II}$ and choose the correct option. $$\begin{array}{ll}\text{List-I}& \text{List-II}\\ \text{(P) }\mathrm{Xe}{\mathrm{F}}_2& \text{(1) Trigonal bipyramidal and two lone pair of electrons}\\ \text{(Q) }\mathrm{Xe}{\mathrm{F}}_4& \text{(2) Tetrahedral and one lone pair of electrons}\\ \text{(R) }\mathrm{Xe}{\mathrm{O}}_3& \text{(3) Octahedral and two lone pair of electrons}\\ \text{(S) }\mathrm{Xe}{\mathrm{O}}_3{\mathrm{F}}_2& \text{(4) Trigonal bipyramidal and no lone pair of electrons}\\ & \text{(5) Trigonal bipyramidal and three lone pair of electrons}\end{array}$$

1. A.P-5, Q-2, R-3, S-1
2. B.P-5, Q-3, R-2, S-4
3. C.P-4, Q-3, R-2, S-1
4. D.P-4, Q-2, R-5, S-3

Among $[{\mathrm{I}}_3{]}^{+}$, $[{\mathrm{SiO}}_4{]}^{4-}$, $\mathrm{S}{\mathrm{O}}_2\mathrm{C}{\mathrm{l}}_2$, $\mathrm{Xe}{\mathrm{F}}_2$, $\mathrm{S}{\mathrm{F}}_4$, $\mathrm{Cl}{\mathrm{F}}_3$, $\mathrm{Ni}(\mathrm{CO}{)}_4$, $\mathrm{Xe}{\mathrm{O}}_2{\mathrm{F}}_2$, $[{\mathrm{PtCl}}_4{]}^{2-}$, $\mathrm{Xe}{\mathrm{F}}_4$, and $\mathrm{SOC}{\mathrm{l}}_2$, the total number of species having $s{p}^3$ hybridised central atom is _______.