Question

The intermolecular interaction that is dependent on the inverse cube of distance between the molecules is

• A. ion-ion interaction
• B. ion-dipole interaction
• C. London force
• D. hydrogen bond

Answer 1

The Correct Option is D

The question requires identifying the intermolecular interaction that depends on the inverse cube of the distance between the molecules. Here, we must look at the fundamental nature of each type of interaction to determine the correct answer.

1. Ion-Ion Interaction: These are electrostatic interactions between ions that follow Coulomb's Law, where the potential energy decreases with the inverse first power of distance (V \propto \frac{1}{r}), not the inverse cube.
2. Ion-Dipole Interaction: These interactions occur between an ion and a polar molecule, where the potential energy depends on the inverse square of the distance (V \propto \frac{1}{r^2}), not the inverse cube.
3. London Force (London Dispersion Forces): These are weak intermolecular forces arising from induced instantaneous dipoles, and the interaction strength varies with the inverse sixth power of the distance (V \propto \frac{1}{r^6}).
4. Hydrogen Bond: This is a special type of dipole-dipole attraction occurring between hydrogen, which is covalently bonded to a highly electronegative atom, and another electronegative atom with a lone pair. The potential energy associated with hydrogen bonds is typically described as under inverse cube dependence with distance (V \propto \frac{1}{r^3}).

Based on the analysis above, the intermolecular interaction that is characterized by dependence on the inverse cube of distance between the molecules is the hydrogen bond. Thus, the correct answer is hydrogen bond.