List of top Chemistry Questions on Chemical bonding and molecular structure asked in JEE Advanced

A sample initially contains only U-238 isotope of uranium. With time, some of the U-238 radioactively decays into Pb-206 while the rest of it remains undisintegrated.
When the age of the sample is P x10⁸ years, the ratio of mass of Pb-206 to that of U-238 in the sample is found to be 7. The value of P is _____.
[Given: Half-life of U-238 is 4.5 x10⁹ years; log_e2 = 0.693]

Among [Co(CN)₄]⁴⁻, [Co(CO)₃(NO)], XeF₄, [PCl₄ ]⁺, [PdCl₄ ]²⁻ , [ICl₄ ]⁻ , [Cu(CN)₄]³⁻ and P₄ the total number of species with tetrahedral geometry is _____.

The species formed on fluorination of phosphorus pentachloride in a polar organic solvent are

The option(s) in which at least three molecules follow Octet Rule is(are)

Based on VSEPR model, match the xenon compounds given in List-I with the corresponding geometries and the number of lone pairs on xenon given in List-II and choose the correct option.

List I		List II
(P)	XeF2	(1)	Trigonal bipyramidal and two lone pair of electrons
(Q)	XeF4	(2)	Tetrahedral and one lone pair of electrons
(R)	XeO3	(3)	Octahedral and two lone pair of electrons
(S)	XeO3F2	(4)	Trigonal bipyramidal and no lone pair of electrons
		(5)	Trigonal bipyramidal and three lone pair of electrons

Consider the following molecules : \(Br_3O_8\), \(F_2O\), \(H_2S_4O_6\), \(H_2S_5O_6\), and \(C_3O_2\). Count the number of atoms existing in their zero oxidation state in each molecule. Their sum is _______.

For diatomic molecules, the correct statement(s) about the molecular orbitals formed by the overlap to two $2 p_z$ orbitals is(are)

For diatomic molecules, the correct statement(s) about the molecular orbitals formed by the overlap to two $2 p_z$ orbitals is(are)

The amount of energy required to break a bond is the same as the amount of energy released when the same bond is formed. In a gaseous state, the energy required for homolytic cleavage of a bond is called Bond Dissociation Energy (BDE) or Bond Strength. BDE is affected by the s-character of the bond and the stability of the radicals formed. Shorter bonds are typically stronger bonds. BDEs for some bonds are given below:

The $1^{\text {st }}, 2^{\text {nd }}$, and the $3^{\text {rd }}$ ionization enthalpies, $I_{1}, I_{2}$, and $I_{3}$, of four atoms with atomic numbers $n, n+1$, $n+2$, and $n+3$, where 𝑛 < 10, are tabulated below. What is the value of n?

Atomic Number	Ionization Enthalpy (kJ/mol)
	I1	I2	I3
n	1681	3374	6050
n+1	2081	3952	6122
n+2	469	4562	6910
n+3	738	1451	7733

The figure below is the plot of potential energy versus internuclear distance $(d)$ of $H _{2}$ molecule in the electronic ground state. What is the value of the net potential energy $E_{0}$ (as indicated in figure) in $kJ\, mol ^{-1}$, for $d=d_{0}$ at which the electron-electron repulsion and the nucleus-nucleus repulsion energies are absent? As reference, the potential energy of $H$ atom is taken as zero when its electron and the nucleus are infinitely far apart. Use Avogadro constant as $6.023 \times 10^{23} mol ^{-1}$

Each of the following options contains a set of four molecules. Identify the option(s) where all four molecules possess permanent dipole moment at room temperature.

Assuming $2s-2p$ mixing is not operative, the paramagnetic species among the following is

The shape of $XeO_2F_2$ molecule is

Assuming that Hund's rule is violated, the bond order and magnetic nature of the diatomic molecule $B_2$ is

Among the following, the molecule with the highest dipole moment is

Among the following species, identify the isostructural pairs. $NF_3$, $NO_3^-$, $BF_3$, $H_3O^+$, $N_3H$

The linear structure assumed by