Chemical bonding & molecular structure practice · Medium

The correct answer is C (Hydrogen sulphide) because hydrogen bonding requires a hydrogen atom bonded to a highly electronegative atom like F, O, or N, which is not the case in hydrogen sulfide.

The correct answer is $\frac{1.03 \times 100 \times 10^{-18}}{4.8 \times 10^{-10} \times 1.275 \times 10^{-8}}$. Percent polarity is calculated by dividing the observed dipole moment by the calculated dipole moment and multiplying by 100.

Option B (${H}_2 {O}_2$) is correct because both ${O}_2 {~F}_2$ and ${H}_2 {O}_2$ have a similar peroxide structure.

Option A is correct because the polar character increases with the electronegativity difference between the bonded atoms, and the order of electronegativity is S < N < O < F.

The correct answer is B (HCOOH and CH3COOH) because carboxylic acids form strong hydrogen bonds due to dimerization.

Option A is correct because the lattice energy of ionic compounds depends on both the charge and size of the ions, as described by Coulomb's law.

Option B is correct because HCl is a covalent compound with weak intermolecular forces, resulting in a lower melting point compared to the ionic compounds CsF, HF, and LiF.

Option B ($\mathrm{PO}_4^{3 - }$) is correct because phosphorus has available d-orbitals, allowing for $p\pi - d\pi$ bonding with oxygen.

Option B is correct because a low ionization energy for A and a high electron affinity for B favor the formation of ions ${A^ + }$ and ${B^ - }$ respectively, leading to an ionic bond.

Option C (Mulliken) is correct because Robert S. Mulliken is credited with the development of the Molecular Orbital Theory.

Option B ($\mathrm{O}_2^{-} > \mathrm{O}_2 > \mathrm{O}_2^+$) is correct because bond length is inversely proportional to bond order, and the bond orders are O2- (1.5), O2 (2), and O2+ (2.5).

Option A (The energy of the resonance hybrid is more than the energy of any single canonical structure) is correct because the resonance hybrid is more stable and thus has lower energy than any individual contributing canonical structure.